Health Hazard Evaluation Report 2012-0170-3372 Page 1

Evaluation of exposures and respiratory health 

at a coffee roasting, flavoring, and packaging 

facility

Report No. 2012-0170-3372

April 2020

U.S. Department of Health and Human Services

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

Rachel L. Bailey, DO, MPH

Matthew G. Duling, MS, REHS

Stephen B. Martin, Jr., PhD, PE

Marcia L. Stanton, BS

Tia L. McClelland, MS

Ryan F. LeBouf, PhD, CIH

Nicole T. Edwards, MS

Kathleen B. Fedan, BS 

Jean M. Cox-Ganser, PhD 
Page 2 Health Hazard Evaluation Report 2012-0170-3372

Contents

Highlights.............................................. i

Abbreviations ...................................... 1

Summary.............................................. 2 

Introduction......................................... 3

Background.......................................... 4

Facility and Process Description......... 8

Methods ............................................. 13

Results ................................................ 23

Discussion .......................................... 37

Conclusions........................................ 47

Recommendations............................. 48

Appendix A: Tables............................ 53

References.......................................... 78

Acknowledgements........................... 88

The employer is required to post a copy of this report for 30 days at or near the 

workplace(s) of affected employees. The employer must take steps to ensure 

that the posted report is not altered, defaced, or covered by other material.

The cover photo is a close-up image of sorbent tubes, which are used by the HHE

Program to measure airborne exposures. This photo is an artistic representation that may

not be related to this Health Hazard Evaluation.
Health Hazard Evaluation Report 2012-0170-3372 Page i

Highlights of this Evaluation

The Health Hazard Evaluation Program of the National Institute for Occupational Safety 

and Health received a confidential request from employees at a coffee roasting, flavoring, 

and packaging facility regarding concerns about respiratory symptoms, lung disease, and 

eye irritation related to substances used in the 

manufacturing of coffee products, including 

ingredients mixed in the flavoring process.

What We Did

● We conducted a walkthroug visit of the 

facility in July/August 2012.

○ We performed a medical survey in 

September 2012.

○ We administered a health questionnaire, 

performed breathing tests, and offered 

blood tests.

○ We notified participants of their 

individual medical test results.

● We performed a medical survey in 

September 2012. 

○ We administered a health questionnaire, 

performed breathing tests, and offered 

blood tests.

○ We notified participants of their 

individual medical test results.

● We performed an industrial hygiene survey 

in November 2012.

○ We collected full-shift (hours), task 

(minutes), and instantaneous (seconds) 

air samples to measure concentrations 

of diacetyl and 2,3-pentanedione over 

multiple days.

○ We measured airborne dust 

concentrations throughout the facility. 

○ We collected bulk samples of liquid 

flavorings to measure their emission 

potential for diacetyl, 2,3-pentanedione, 

and 2,3-hexanedione.

● We performed an industrial hygiene survey 

in April 2017.

○ We collected full-shift (hours), 

task (minutes), and instantaneous 

We evaluated respiratory health and airborne 

exposures to alpha-diketones (diacetyl, 

2,3-pentanedione, and 2,3-hexanedione), dust, 

other volatile organic compounds, carbon 

monoxide, and carbon dioxide during coffee 

roasting, grinding, flavoring, and packaging. 

Diacetyl and 2,3-pentanedione were detected in 

a majority of full-shift personal breathing zone 

air samples. During the November 2012 visit, the 

maximum concentration of diacetyl was 166.0 parts 

per billion in a personal sample from a packaging 

employee while the maximum 2,3-pentanedione 

concentration was 199.0 parts per billion from 

a personal sample collected on an employee 

in the flavoring room. In April 2017, personal 

samples from employees in the flavoring room 

gave maximum concentrations of 163.8 parts 

per billion diacetyl and 899.6 parts per billion 

2,3-pentanedione. In November 2012, 58 of 59 

full-shift personal samples exceeded the NIOSH 

recommended exposure limit for diacetyl of 5 

parts per billion and 42 of 59 samples exceeded 

the NIOSH recommended exposure limit for 

2,3-pentanedione of 9.3 parts per billion. In April 

2017, 28 of 29 full-shift personal samples exceeded 

the NIOSH recommended exposure limits for 

diacetyl and 2,3-pentanedione. The production 

volume in April 2017 was approximately 70% 

higher than our first visit which likely contributed to 

the higher concentrations measured in some areas. 

During the medical survey, eye and nose symptoms 

were the most commonly reported symptoms; 

1.6-fold excess of employees reported shortness 

of breath compared to the U.S. population with a 

similar demographic distribution, and 2.7 times 

as many employees as expected had spirometric 

obstruction than in the U.S. population. We 

recommend installing local exhaust and dilution 

ventilation and implementing administrative 

controls such as modification of work practices. 

Until engineering and administrative controls are 

in place, we recommend respiratory protection to 

reduce exposures to alpha-diketones. The choice of 

respirator should be guided by personal exposure 

sampling for diacetyl and 2,3-pentanedione and 

be made only by qualified personnel. We also 

recommended continuing the medical surveillance 

program.
Page ii Health Hazard Evaluation Report 2012-0170-3372

(seconds) air samples to measure concentrations of diacetyl, 2,3-pentanedione, and 

2,3-hexanedione.

○ We measured real-time air levels of carbon monoxide and carbon dioxide.

○ We collected additional bulk samples of liquid flavorings.

● We assessed the ventilation system at the facility in November 2012 and April 2017.

● We provided seven interim reports with recommendations to the company following our 

visits. 

What We Found

● Production volume increased approximately 70% between 2012 and 2017 which made 

direct comparison of sampling results between the two visits difficult. Personal full-shift 

sampling results exceeded the NIOSH recommended exposure limits for both diacetyl 

and 2,3-pentanedione in 2012 and 2017.

● In November 2012, area sample diacetyl concentrations were highest in packaging (112.2 

parts per billion) and the packaging mezzanine (247.2 parts per billion). In 2017, the 

flavoring room (372.0 parts per billion) and flavoring mezzanine (251.3 parts per billion) 

had the highest concentrations. 

● In November 2012, one personal sample in the nonproduction offices exceeded the 

NIOSH recommended exposure limit for diacetyl. Prior to the April 2017 survey, the 

air handling unit serving the nonproduction offices was replaced resulting in no samples 

exceeding the exposure limits.

● In November 2012 and April 2017, area 2,3-pentanedione concentrations were highest 

in the flavoring room (273.1 parts per billion, 2012; 1285.3 parts per billion, 2017) and 

flavoring mezzanine (206.4 parts per billion, 2012; 2060.3 parts per billion, 2017). 

● Source sampling results in November 2012 showed the storage bins on the packaging 

mezzanine had the highest concentrations of diacetyl and 2,3-pentanedione. As a result, 

the packaging mezzanine was enclosed and ventilated prior to our April 2017 survey. 

● Diacetyl was identified in 11 of 13 bulk flavoring samples. Compared to diacetyl, 

higher concentrations of 2,3-pentanedione were identified in almost all the flavorings. 

2,3-Hexanedione was measured in five samples.

● In November 2012, air samples for dust were below occupational exposure limits. Dust 

samples were not collected in April 2017. 

● Employees used brooms to sweep the production floor, wet or dry wipes on table tops 

and equipment surfaces, and compressed air to remove coffee bean dust from surfaces 

and equipment. In response to a NIOSH recommendation after the November 2012 visit, 

the facility reduced the use of compressed air for cleaning and placed industrial vacuums 

throughout the production spaces for use in cleaning tasks.

● Ventilated enclosures were installed around all grinders prior to our November 2012 visit. 

An assessment of those enclosures showed they were largely ineffective. Before our April 
Health Hazard Evaluation Report 2012-0170-3372 Page iii

2017 visit, enclosures around two grinders were improved, and the third grinder was 

completely replaced with a sealed grinder to reduce emissions. The April 2017 survey 

revealed that additional improvements are needed.

● Peak levels of carbon monoxide inside the flavoring room grinder enclosure exceeded 

the NIOSH ceiling of 200 parts per million; employees typically do not enter the grinder 

enclosure during operation.

● In July/August 2012, N95 filtering facepiece respirators were available but not required. 

In September 2012, flavoring specialists and mixers sometimes wore half-face air- purifying respirators. In November 2012, flavoring employees were required to wear fullface powered air-purifying respirators. In April 2017, half-face air-purifying respirators 

were required in flavoring, the packaging mezzanine, while feeding roasted coffee into 

the new corner-seal packaging line, and during rework. 

● During the September 2012 medical survey of current employees at the coffee facility:

○ Eye and nose symptoms were the most commonly reported symptoms. 

○ Some participants with mucous membrane irritation of eyes, nose, or sinuses 

attributed it to green coffee or roasted coffee dust, smoke, pallet dust/debris, heat in 

the roasting room, or the burlap bags.Shortness of breath was the most commonly 

reported lower respiratory symptom followed by chest wheezing or whistling, trouble 

breathing, and cough.

○ Of 69 participants with spirometry, five had obstructive abnormalities, two had 

restrictive abnormalities, and eight had low FEF25-75.

○ Current coffee plant employees had a 2.7-fold excess of spirometric obstruction and 

1.6-fold excess of shortness of breath (when hurrying on level ground or walking up 

a slight hill) compared to the U.S. population of the same age, race/ethnicity, sex, and 

cigarette smoking distribution.

○ Spending work time in the roasting room was associated with having trouble with 

breathing, wheeze, sinus symptoms, and burning eyes in the last 12 months. There 

were no significant associations between symptoms and currently spending work time 

in the flavoring room or grinding/packaging room.

○ Five of 45 participants who completed the mannitol challenge test had abnormal tests 

reflecting bronchial hyperactivity. Two of the five reported no respiratory symptoms, 

excluding the diagnosis of clinical asthma. 

○ All 60 participants who took the blood test had evidence of being exposed to green 

coffee beans by their immunoglobulin G levels; 22 participants had high levels of 

total immunoglobulin E; one participant had specific immunoglobulin E to coffee or 

green coffee beans, and one participant had specific immunoglobin E to castor beans.

● Of 13 former employees, five reported physician-diagnosed obliterative bronchiolitis, 

a serious, often disabling lung disease; all five had abnormal spirometry that was 

not reversible with bronchodilator. Another former employee had elevated total 

immunoglobulin E and specific immunoglobulin E to green coffee, coffee, and caster 

bean allergens. 

● The company started a medical surveillance program; NIOSH reviewed company 

spirometry and found it to be of good quality. 
Page iv Health Hazard Evaluation Report 2012-0170-3372

○ Of 27 employees tested by NIOSH who also had a company-provided spirometry 

test, one had a drop in FEV1 greater than 15% after expected loss due to aging.

○ Of 23 employees who did not have NIOSH spirometry testing but had two companyprovided spirometry tests, none had excessive drops in FEV1 or FVC.

What the Employer Can Do

● Ensure employees understand potential hazards (e.g., diacetyl, 2,3-pentanedione, carbon 

monoxide, carbon dioxide, green and roasted coffee dust) in the workplace and how to 

protect themselves.

● Continue working with a qualified ventilation contractor to improve existing local 

exhaust ventilation systems and install additional systems targeted at specific points along 

production lines to capture alpha-diketones at their source.

● Increase the amount of outdoor air supplied to areas where local exhaust ventilation 

is not feasible or cannot reduce concentrations below NIOSH recommended exposure 

limits. Ensure that outdoor air is supplied from an area free of contamination from 

existing exhaust systems.

● Modify existing ventilation systems serving the production offices, breakroom and locker 

rooms to ensure that no air from the production area is recirculated into those areas.

● Conduct follow-up air sampling to verify that any modifications made were effective in 

reducing exposures to below the recommended exposure limits.

● Eliminate the use of compressed air as much as possible during cleaning. Instead, use 

a vacuum system with a high-efficiency particle air filter and wet methods whenever 

possible. 

● Until engineering and administrative controls are in place, respiratory protection for 

diacetyl and 2,3-pentanedione should continue to be used to reduce exposures to alphadiketones. The choice of respirator should be guided by personal exposure sampling for 

diacetyl and 2,3-pentanedione.

● Ensure employees required to use respiratory protection receive an annual medical 

evaluation, training, and fit testing, along with all other elements of a written respiratory 

protection program as required by the Occupational Safety and Health Administration 

Respiratory Protection Standard (29 Code of Federal Regulations part 1910.134). 

● Continue to make N95 disposable filtering facepiece respirators available for voluntary 

use for protection against dust exposure. 

● Encourage employees to report new, worsening, or ongoing respiratory symptoms to their 

healthcare providers and to a designated individual at the workplace.

● Maintain the medical surveillance program for employees who work in the production 

area.
Health Hazard Evaluation Report 2012-0170-3372 Page v

What Employees Can Do

● Use any local exhaust ventilation as instructed by your employer. 

● Use respirators when required according to your employer’s written respiratory 

protection program as required by the Occupational Safety and Health Administration 

Respiratory Protection Standard (29 Code of Federal Regulations part 1910.134). 

● Some employees may wish to use N95 disposable filtering facepiece respirators when 

emptying burlap bags of green beans into the roaster dump stations, cleaning the roaster 

exhaust system of chaff, when emptying the chaff containers, or cleaning the green bean 

storage area.

● Report new, persistent, or worsening respiratory symptoms to your healthcare providers 

and a designated individual at your workplace. 

● Participate in your employer’s surveillance program.

● Report new, persistent, or worsening respiratory symptoms to your personal healthcare 

provider(s) and, as instructed, to a designated individual at your workplace. 

● Participate in your employer’s medical monitoring program as instructed by your 

employer. 
Page vi Health Hazard Evaluation Report 2012-0170-3372

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Health Hazard Evaluation Report 2012-0170-3372 Page 1

Abbreviations 

μm Micrometer

μg Microgram

μg/cc Microgram per cubic centimeter

°F degrees Fahrenheit

ACGIH® American Conference of Governmental Industrial Hygienists

APF Assigned protection factor

BMI Body mass index

cfm Cubic feet per minute

CFR Code of Federal Regulations

CO Carbon monoxide

CO2 Carbon dioxide

DLCO Diffusing capacity of the lung for carbon monoxide 

FEV1 1-second forced expiratory volume

FEF25-75 Forced mid-expiratory flow

FID Flame ionization detector

FVC Forced vital capacity

GC Gas chromatograph

IDLH Immediately dangerous to life or health

Ig Immunoglobulin

IOM Institute of Occupational Medicine

kU/L Kilounits per liter 

L Liter

LEV Local exhaust ventilation

LPM Liters per minute

LOD Limit of detection

LOQ Limit of quantitation

mgA/L Milligrams of antigen specific-antibodies per liter 

mg/m3 Milligrams per cubic meter of air

mL Milliliter

mL/min Milliliter per minute

NHANES National Health and Nutrition Examination Survey

NIOSH National Institute for Occupational Safety and Health

OSHA Occupational Safety and Health Administration

PAPR Powered air-purifying respirator

PEL Permissible exposure limit

ppb Parts per billion

ppm Parts per million

PVC Polyvinyl chloride 

REL Recommended exposure limit

RH Relative humidity

SDS Safety data sheet

SMR Standardized morbidity ratio

STEL Short-term exposure limit

TLV® Threshold limit value

TVOC Total volatile organic compound

TWA Time-weighted average

VOC Volatile organic compound
Page 2 Health Hazard Evaluation Report 2012-0170-3372

Summary 

Physicians at a university medical center diagnosed obliterative bronchiolitis, a serious, 

often disabling lung disease, in five former employees of the coffee roasting, flavoring, and 

packaging facility. In April 2012, the National Institute for Occupational Safety and Health’s 

Health Hazard Evaluation Program received a confidential employee request from a coffee 

roasting, flavoring, and packaging facility with approximately 85 employees. The requestors 

had concerns about respiratory symptoms, lung disease, and eye irritation related to the 

manufacturing of coffee products, including ingredients used in the flavoring process. In 

July/August 2012, we conducted an initial walkthrough site visit at the facility. In September 

2012, we conducted a medical survey; we administered a questionnaire, performed breathing 

tests, and measured antibodies in blood. In November 2012, we conducted an industrial 

hygiene survey and ventilation assessment at the facility. The industrial hygiene survey 

consisted of collecting personal breathing zone and area air samples for alpha-diketones 

(i.e., diacetyl and 2,3-pentanedione) and dust. Bulk samples of whole bean green and roasted 

coffee, ground roasted coffee, and liquid flavorings were collected to evaluate the potential 

for emission of diacetyl and 2,3-pentanedione. We used continuous monitoring instruments 

to measure total volatile organic compounds, carbon monoxide, carbon dioxide, temperature, 

and relative humidity in specific areas and during tasks. 

During the medical survey at the facility, the most commonly reported symptoms were eye 

and nose symptoms. Shortness of breath was the most commonly reported lower respiratory 

symptom followed by chest wheezing or whistling, trouble breathing, and cough. Current 

coffee plant employees had a 2.7-fold excess of spirometric obstruction and 1.6-fold excess 

of shortness of breath compared to the U.S. population. Spending work time in the roasting 

room was associated with having trouble with breathing, wheeze, sinus symptoms, and 

burning eyes in the last 12 months. There were no significant associations between symptoms 

and currently spending work time in the flavoring room or grinding/packaging room. Five 

of 45 participants who completed the mannitol challenge test had abnormal tests reflecting 

bronchial hyperactivity; two of the five reported no respiratory symptoms, excluding a 

diagnosis of clinical asthma. All 60 participants who took the blood tests had evidence of 

being exposed to green coffee beans by their immunoglobulin G levels; 22 participants 

had high levels of total immunoglobulin E; one participant had specific immunoglobulin 

E to coffee or green coffee beans, and one participant had specific immunoglobulin E to 

castor beans. Of 13 former employees, five reported physician-diagnosed obliterative 

bronchiolitis; all five had abnormal spirometry. Another former employee had elevated total 

immunoglobulin E and abnormal specific immunoglobulin E to green coffee, coffee, and 

caster bean allergens. 

During the November 2012 industrial hygiene survey, employees in the grinding/packaging 

area for unflavored coffee had the highest mean diacetyl exposures, with personal 

concentrations averaging 93 parts per billion (ppb). This area was under positive pressure 

with respect to flavored coffee production (mean personal diacetyl levels of 80 ppb). 

The 2,3-pentanedione exposures were highest in the flavoring room with mean personal 

exposures of 122 ppb, followed by exposures in the unflavored coffee grinding/packaging 
Health Hazard Evaluation Report 2012-0170-3372 Page 3

area (53 ppb). Peak 15-minute airborne concentrations of 14,300 ppb diacetyl and 13,800 

ppb 2,3-pentanedione were measured at a small open hatch in the lid of a hopper containing 

ground unflavored coffee on the mezzanine over the grinding/packaging area. Three out of 

the four bulk coffee flavorings tested had at least a factor of two higher 2,3-pentanedione than 

diacetyl headspace measurements. Six interim reports providing results and recommendations 

were sent to the company following the 2012 surveys. 

To evaluate the process and ventilation changes made by the company in response to 

NIOSH recommendations, we conducted a second industrial hygiene survey and ventilation 

assessment in April 2017. We also reviewed the quality of spirometry tests performed by 

the company’s medical surveillance provider and found the spirometry results to be of good 

quality. The industrial hygiene survey included the collection of general area and personal air 

and bulk samples for diacetyl, 2,3-pentanedione, and 2,3-hexanedione. We used continuous 

monitoring instruments to measure total volatile organic compounds, carbon monoxide, and 

carbon dioxide in specific areas and during specific work tasks. Source sampling results 

in November 2012 showed the storage bins on the packaging mezzanine had the highest 

concentrations of diacetyl and 2,3-pentanedione. As a result, the packaging mezzanine was 

enclosed and ventilated prior to our April 2017 survey. Overall, time-weighted average air 

concentrations of diacetyl and 2,3-pentanedione were consistently higher during our second 

industrial hygiene survey. In April 2017, the production volume was approximately 70% 

higher than our first visit which likely contributed to the higher concentrations measured in 

some areas. We identified jobs where some work tasks resulted in higher air concentrations 

of diacetyl and 2,3-pentanedione than other tasks. Specifically, grinding, weighing and 

packaging, and flavoring roasted coffee beans were associated with higher diacetyl and 

2,3-pentanedione levels. 

We recommend installing local exhaust and dilution ventilation and implementing 

administrative controls such as modification of work practices. Until engineering and 

administrative controls are in place, we recommend respiratory protection to reduce 

exposures to alpha-diketones. The choice of respirator should be guided by personal exposure 

sampling for diacetyl and 2,3-pentanedione. We also recommend continuing the medical 

surveillance program.

Introduction

In June 2012, the National Institute for Occupational Safety and Health (NIOSH) received a 

confidential employee request for a health hazard evaluation at a coffee roasting, flavoring, 

and packaging facility regarding concerns about respiratory symptoms, lung disease, and 

eye irritation related to the manufacturing of coffee products, including ingredients used in 

the flavoring process. In July/August 2012, we conducted a walkthrough visit at the facility. 

In September 2012, we conducted a medical survey that consisted of a medical and work 

history questionnaire, spirometry, administration of bronchodilator or mannitol challenge 

test, tests for carbon monoxide diffusing capacity and alveolar volume, and blood tests for 

immune responsiveness. In November 2012, we conducted a ventilation assessment and 
Page 4 Health Hazard Evaluation Report 2012-0170-3372

industrial hygiene survey. We collected area and personal breathing zone air samples for dust 

and volatile organic compounds (VOCs), including diacetyl and 2,3-pentanedione. In April 

2017, we conducted a second ventilation assessment and industrial hygiene survey. During 

the 2017 visit, the total daily production volume at the plant was 70% higher than in 2012. 

We collected area and personal breathing zone air samples for VOCs, including diacetyl, 

2,3-pentanedione, and 2,3-hexanedione. We also measured carbon monoxide (CO), carbon 

dioxide (CO2), and total VOCs (TVOCs) in air using real-time instruments. 

Background 

Physicians at a university medical center diagnosed obliterative bronchiolitis, a serious, often 

disabling lung disease, in five individuals who had worked at a coffee roasting, grinding, 

flavoring, and packaging facility. In June 2012, employees at the facility requested a NIOSH 

health hazard evaluation.

Diacetyl and 2,3-Pentanedione 

Diacetyl (2,3-butanedione) and 2,3-pentanedione (acetyl propionyl) are VOCs known as 

alpha-diketones that are added as ingredients in food flavorings used in some food products 

such as microwave popcorn, bakery mixes, and flavored coffee [Kanwal et al. 2006; 

Martyny et al. 2008; Day et al. 2011; LeBouf et al. 2019; Harvey et al. 2020]. Diacetyl, 

2,3-pentanedione, other VOCs, and gases such as CO and CO2 are naturally produced and 

released during the coffee roasting process [Raffel and Thompson 2013; Daglia et al. 2007; 

Nishimura et al. 2003; Newton 2002]. Grinding roasted coffee beans produces a greater 

surface area for off-gassing (sometimes called degassing) of these compounds [Akiyama 

et al. 2003]. Often, coffee roasting facilities package newly roasted coffee in permeable 

bags or in bags fitted with one-way valves to allow the coffee to off-gas after it is packaged. 

Sometimes, newly roasted coffee is placed in bins or containers and allowed to off-gas before 

packaging. 

NIOSH has recommended exposure limits (RELs) for diacetyl and 2,3-pentanedione in 

workplace air (Table 1) [NIOSH 2016a]. The NIOSH objective in establishing RELs for 

diacetyl and 2,3-pentanedione is to reduce the risk of respiratory impairment (decreased lung 

function) and the severe irreversible lung disease obliterative bronchiolitis associated with 

occupational exposure to these chemicals. The NIOSH RELs are intended to protect workers 

exposed to diacetyl or 2,3-pentanedione for a 45-year working lifetime. The REL for diacetyl 

is based on a quantitative risk assessment which necessarily contains assumptions and some 

uncertainty. Analytical limitations current at the time were taken into consideration in setting 

the REL for 2,3-pentanedione. The RELs should be used as a guideline to indicate when steps 

should be taken to reduce exposures in the workplace.

These exposure limits and the accompanying recommendations for control of exposures 

were derived from a risk assessment of flavoring-exposed workers. At an exposure equal to 

the diacetyl REL, the risk of adverse health effects is low. NIOSH estimated that less than 1 

in 1,000 workers exposed to diacetyl levels of 5 parts per billion (ppb) as a time-weighted 
Health Hazard Evaluation Report 2012-0170-3372 Page 5

average (TWA) for 8 hours a day, 40 hours a week for a 45-year working lifetime would develop 

reduced lung function (defined as forced expiratory volume in one second [FEV1] below the 

lower limit of normal) as a result of that exposure. NIOSH predicted that around 1 in 10,000 

workers exposed to diacetyl at 5 ppb for a 45-year working lifetime would develop more severe 

lung function reduction (FEV1 below 60% predicted, defined as at least moderately severe by 

the American Thoracic Society [Pellegrino et al. 2005]). Workers exposed for less time would be 

at lower risk for adverse lung effects.

2,3-Hexanedione

2,3-Hexanedione is also an alpha-diketone sometimes used as a substitute for diacetyl and is 

produced naturally during coffee roasting. In a study using animals, there was some evidence 

that 2,3-hexanedione might also damage the lungs, but it appeared to be less toxic than diacetyl 

and 2,3-pentanedione [Morgan et al. 2016]. There are no established occupational exposure 

limits for 2,3-hexanedione.

Carbon Monoxide and Carbon Dioxide

CO and CO2 are gases produced by combustion. They are also produced as a result of reactions 

that take place during coffee roasting. These gases are released during and after roasting and 

grinding by a process called off-gassing [Anderson et al. 2003; Hawley et al. 2017; LeBouf 

et al. 2018]. High exposures to CO and CO2 can cause headache, dizziness, fatigue, nausea, 

confusion, rapid breathing, impaired consciousness, coma, and death [Newton 2002; Nishimura 

et al. 2003; Langford 2005; CDC 2018; Raffel and Thompson 2013; Rose et al. 2017]. 

Occupational exposure limits for CO and CO2 are listed in Table 1.

Inhalable Dust

Dust refers to the particles present in air, either from natural forces or from mechanical 

processes. Inhalable dust includes particles of various sizes. Some of the particles may be too 

large to enter the deepest areas of the lungs but can enter the nose, mouth, and upper airways 

during breathing. Occupational exposure limits for inhalable dust are listed in Table 1.

Exposure Limits

We utilize mandatory (legally enforceable) and recommended occupational exposure limits 

when evaluating workplace hazards. Occupational exposure limits are developed by federal 

agencies and safety and health organizations to prevent adverse health effects from workplace 

exposures.

Occupational Safety and Health Administration (OSHA) [Mandatory]

The U.S. Department of Labor’s OSHA permissible exposure limits (PELs) are legal limits that 

are enforceable in workplaces covered under the Occupational Safety and Health Act. OSHA 

PELs represent the legal maximum for a TWA exposure to a physical or chemical agent over 

a work shift [OSHA 2019]. OSHA short-term exposure limits (STELs) are the legal maximum 

average exposure for a 15-minute time period. Some chemicals also have an OSHA ceiling 

value which represent levels that must not be exceeded at any time. Currently, there are no PELs 

for diacetyl, 2,3-pentanedione, or 2,3-hexanedione. For substances for which an OSHA PEL has 

not been issued, violation of the OSHA General Duty Clause can be considered using available 
Page 6 Health Hazard Evaluation Report 2012-0170-3372

occupational exposure references and recommendations [OSHA 1993; OSHA 2003], such as 

the American Conference of Governmental Industrial Hygienists (ACGIH®) Threshold Limit 

Values (TLVs®) and NIOSH RELs.

American Conference of Governmental Industrial Hygienists (ACGIH) [Recommended]

ACGIH is a professional, not-for-profit scientific association that reviews existing published, 

peer-reviewed scientific literature and publishes recommendations for levels of substances 

in air based on an 8-hour workday and 40-hour workweek. These recommendations 

are called TLVs [ACGIH 2019]. ACGIH TLVs are not standards; they are health-based 

guidelines derived from scientific and toxicological information. ACGIH provides TLV-TWA 

guidelines that are levels that should not be exceeded during any 8-hour workday of a 40-

hour workweek. ACGIH also provides TLV-STEL guidelines which are 15-minute exposure 

levels that should not be exceeded during a workday. Exposures above the TLV-TWA but less 

than the TLV-STEL should be (1) less than 15 minutes, (2) occur no more than four times a 

day, and (3) be at least 60 minutes between exposures [ACGIH 2019]. Additionally, ACGIH 

provides TLV-Ceiling values which are levels that should not be exceeded at any time during 

a work shift. The ACGIH TLV-TWA for diacetyl is 10 ppb. The TLV-STEL for diacetyl is 20 

ppb. Currently, there is no TLV-TWA or TLV-STEL for 2,3-pentanedione. 

National Institute for Occupational Safety and Health (NIOSH) [Recommended] 

For NIOSH RELs, TWA indicates a time-weighted average concentration for up to a 10-hour 

workday during a 40-hour workweek

NIOSH provides RELs as TWA concentrations that should not be exceeded over an 8 or 

10-hour work shift, during a 40-hour workweek [NIOSH 2016a, 2016b]. RELs are intended 

to be protective over a 45-year working lifetime. NIOSH also provides STELs which are 

15-minute TWA exposures that should not be exceeded at any time during a workday 

[NIOSH 2016b]. Some chemicals have ceiling values which are concentrations that should 

not be exceeded at any time [NIOSH 2016b]. For some chemicals, NIOSH has established an 

Immediately Dangerous to Life or Health (IDLH) value. An IDLH value is a concentration 

of an air contaminant that can cause death or immediate or delayed permanent adverse 

health effects, or prevent escape from such an environment. Currently, NIOSH has RELs and 

STELs for diacetyl and 2,3-pentanedione [NIOSH 2016a]. NIOSH does not have a REL or a 

STEL for 2,3-hexanedione. NIOSH does not have ceiling limits or IDLH values for diacetyl, 

2,3-pentanedione, or 2,3-hexanedione. 

For diacetyl and 2,3-pentanedione, the NIOSH RELs are 5.0 ppb and 9.3 ppb, respectively, 

as a TWA for up to an 8-hour workday during a 40-hour workweek (Table 1). The NIOSH 

STELs are 25 ppb for diacetyl and 31 ppb for 2,3-pentanedione [NIOSH 2016b]. The NIOSH 

exposure limits do not differentiate between natural and synthetic chemical origin of diacetyl 

or 2,3-pentanedione. Although the NIOSH exposure limit for 2,3-pentanedione is above that 

of diacetyl, 2,3-pentanedione has been shown to be as hazardous as diacetyl [Hubbs et al. 

2012; Morgan et al. 2012]. The hazard potential probably increases when these chemicals 

occur in combination with each other; having exposure to chemicals with the same functional 

alpha-diketone group and effect on the same system or organ (e.g., lungs) can result in 
Health Hazard Evaluation Report 2012-0170-3372 Page 7

additive effects [ACGIH 2019]. The NIOSH REL is higher for 2,3-pentanedione than for 

diacetyl largely because analytic measures were not available in a validated OSHA method to 

detect 2,3-pentanedione at lower levels. In addition to the REL, NIOSH also recommends an 

action level for diacetyl of 2.6 ppb to be used with exposure monitoring in an effort to ensure 

employee exposures are routinely below the diacetyl REL. When exposures exceed the 

action level, employers should take corrective action (i.e., determine the source of exposure, 

identify methods for controlling exposure) to ensure that exposures are maintained below the 

NIOSH REL for diacetyl [NIOSH 2016a].

Table 1. Personal exposure limits for compounds sampled during NIOSH industrial hygiene 

surveys, November 2012 and April 2017

Compound

OSHA* ACGIH NIOSH

PEL TLV STEL REL STEL IDLH

Diacetyl - 10 ppb 20 ppb 5.0 ppb† 25 ppb -

2,3-Pentanedione - - - 9.3 ppb† 31 ppb -

2,3-Hexanedione - - - - - -

Inhalable dust - 10 mg/m3‡ - - - -

Carbon dioxide§ 5,000 ppm 5,000 ppm 30,000 ppm 5,000 ppm 30,000 ppm 40,000 ppm

Carbon monoxide§ 50 ppm 25 ppm - 35 ppm 200 ppm 1,200 ppm

(ceiling limit)¶

Note: OSHA=Occupational Safety and Health Administration; ACGIH=American Conference of Governmental 

Industrial Hygienists; NIOSH=National Institute for Occupational Safety and Health; PEL=permissible exposure limit; 

TLV=threshold limit value; STEL=short-term exposure limit; REL=recommended exposure limit; IDLH=immediately 

dangerous to life or health; mg/m3=milligram per cubic meter; ppb=parts per billion; ppm=parts per million; “-“=no 

exposure limit available. 

*There are no OSHA STELs for the compounds in the table.

†The NIOSH RELs for diacetyl and 2,3-pentanedione are time-weighted averages for up to an 8-hour day, during a 40-hour 

workweek.

‡ACGIH does not have a TLV for inhalable dust but does provide guidelines for total dust; ACGIH guidelines suggests 

airborne concentrations be kept below 10 mg/m3.

§OSHA and NIOSH limits are designed for occupational exposure measurements in manufacturing and other trades that 

have potential sources of carbon dioxide or carbon monoxide (e.g., coffee roasting, welding, vehicle exhaust, diesel engine 

exhaust). Typical levels of carbon monoxide in offices are 0–5 ppm. In office settings, carbon dioxide generally should not be 

greater than 700 ppm above outdoor carbon dioxide levels; this typically corresponds to indoor concentrations below 1200 

ppm. 

¶This is the NIOSH ceiling exposure limit for carbon monoxide. A ceiling concentration should not be exceeded at any time.

Obliterative Bronchiolitis

Obliterative bronchiolitis is a serious, often disabling, lung disease that involves scarring 

of the very small airways (i.e., bronchioles). Symptoms of this disease may include cough, 

shortness of breath on exertion, or wheeze, that do not typically improve away from work 

[NIOSH 2012]. Occupational obliterative bronchiolitis has been identified in flavoring 

manufacturing workers, microwave popcorn workers, and coffee roasting and packaging 

workers who worked with flavoring chemicals or butter flavorings [Kreiss 2013; Kim et al. 

2010; Kanwal et al. 2006; Harvey et al. 2018, 2020]. Recently, obliterative bronchiolitis was 

reported in an individual in India who had worked for 20 years in a coffee facility that roasted 

and ground coffee; he quit after developing respiratory symptoms [Chetambath et al. 2020].
Page 8 Health Hazard Evaluation Report 2012-0170-3372

Work-related Asthma

Work-related asthma refers to asthma that is brought on by (“occupational asthma”) or made 

worse by (“work-exacerbated asthma” or “work-aggravated asthma”) workplace exposures 

[NIOSH 2017; Tarlo 2016; Tarlo and Lemiere 2014; OSHA 2014; Henneberger et al. 2011]. 

Work-related asthma includes asthma due to sensitizers, which cause disease through 

immune (allergic) mechanisms, and asthma due to irritants, which cause disease through 

non-immune mechanisms. Symptoms of work-related asthma include episodic shortness of 

breath, cough, wheeze, and chest tightness. The symptoms may begin early in a work shift, 

towards the end of a shift, or hours after a shift. They generally, but do not always, improve 

or remit during periods away from work, such as on weekends or holidays. 

Green and roasted coffee dust and castor beans (from cross-contamination of bags used 

to transport coffee) are known risk factors for occupational asthma [Figley and Rawling 

1950; Karr et al. 1978; Zuskin et al. 1979, 1985; Thomas et al. 1991]. Persons who become 

sensitized (develop an immune reaction) to coffee dust can subsequently react to relatively 

low concentrations in the air. Others may experience irritant-type symptoms from exposure 

to coffee dust [Oldenburg et al. 2009].

Facility and Process Description

Facility and Workforce

At the time of the initial NIOSH walkthrough in July/August 2012, the plant had 

approximately 85 employees that produced flavored and unflavored whole bean and ground 

roasted coffee and packaged some tea, largely for commercial consumers. The roasting 

facility opened in its current location in May 2003. It consisted of a two-story office space 

directly attached to a one-story steel industrial-style building that contained the production 

operations within several rooms. Most production area rooms (warehouse, roasting room, 

packaging/grinding room, hold room, production support corridor) were not completely 

isolated, as walls did not always extend to the ceiling, and large curtained openings 

between the spaces existed to facilitate forklift traffic. The flavoring room was isolated with 

walls to the ceiling and had a 0.12-gauge polyvinyl chloride (PVC) ribbed strip curtain 

door separating it from unflavored coffee production. The flavoring room was kept under 

negative air pressure with respect to the other production areas, to prevent contamination 

of unflavored coffee with flavorings. The employees worked day and evening shifts that 

sometimes overlapped, depending on job responsibilities. Most employees worked 8-hour 

shifts; however, sometimes employees in the flavoring room worked 12-hour shifts, three or 

four days per week, and others worked overtime hours depending on the orders for that week.

Warehouse

The warehouse was separated into finished goods and greens (green coffee bean storage) 

areas by a wall with two breezeways at each end. Loading docks with overhead doors were 

located on the back wall of the warehouse. Green coffee beans were delivered in burlap bags 

to the facility by trucks. In April 2017, we were told the production volumes had increased 

substantially. The amount of green coffee beans stored in the greens warehouse had increased 

noticeably. 
Health Hazard Evaluation Report 2012-0170-3372 Page 9

Employees known as greens unloaders transferred the bags onto pallets, which were then 

moved and stacked in the greens warehouse via forklifts. When the green coffee beans were 

needed for processing, material handlers moved the pallets and placed them at the dumping 

station for each roasting line.

Material handlers also moved palletized finished goods by forklift through PVC ribbed strip 

curtain doorways from the grinding/packaging room and the flavoring room into the finished 

goods warehouse. The finished goods warehouse had a small shipping and receiving office in 

the back corner near the overhead doors where truck drivers took delivery of finished goods. 

There was also an area where small orders were packaged for mail shipment. 

Roasting Room

Employees known as greens dumpers emptied burlap bags of green coffee beans into hoppers 

in the floor. The beans were then automatically fed into a perforated cylinder within a large 

gas-fired coffee roaster. Employees known as roasters stood nearby to monitor the process, 

including listening for the “first crack” and checking for the proper color and smell of roasted 

beans. Throughout their shift, roasters took samples of roasted coffee beans to the quality 

control room. In the quality control room, roasters ground the beans and used an instrument 

to evaluate the color of the roasted coffee.

When the roasting process was completed, beans were emptied into a large cooling bin to 

cool; they were automatically stirred and aerated to ensure even cooling. Afterward, the 

roasted beans were transferred by a bucket elevator system to large hoppers on a mezzanine 

above the packaging lines in the grinding/packaging room or to hoppers on the mezzanine in 

the flavoring room. The roasting room was separated from the grinding/packaging room by a 

PVC ribbed strip curtain doorway. Roasters and dumpers used brooms and compressed air to 

clean their work areas.

Grinding/Packaging Room – Unflavored Coffee

The grinding/packaging room consisted of six packaging lines for unflavored coffee, a 

mezzanine above the lines with hoppers for unflavored whole beans and ground coffee, a 

tea machine and associated mezzanine, and a hand packing station. Whole coffee beans 

delivered from the roasting room were stored in the mezzanine bean hoppers until they were 

ready to be ground or packed on the lines below. For ground coffee, the beans dropped into 

one of two grinding machines, after which it was sent up to the mezzanine ground coffee 

hoppers. Ground or whole coffee was placed in bags with exhaust valves to off-gas CO2 and 

volatiles. Coffee to be packed in non-valved bags required a 12-hour off-gassing period in the 

mezzanine hoppers prior to packaging. 

When ready to be bagged, whole coffee beans or ground coffee dropped to one of the six 

packaging machines that filled bags and placed them on a conveyer belt. The grinding and 

packaging machine operators frequently climbed the mezzanine stairs to inspect hopper 

material levels and dislodge material. Packers and helpers placed cardboard boxes at the 

end of the conveyer belt to place bagged coffee in boxes. A material handler transported the 

pallets using a forklift to the finished goods warehouse. 
Page 10 Health Hazard Evaluation Report 2012-0170-3372

A tea machine operator ran the equipment that filled bags with tea, and then boxed them. The 

tea arrived fully-processed at the plant, where it was essentially repackaged from large sacks 

to smaller bags for customers.

At the hand packing station, employees known as hand packers completed small batch 

orders, such as those from small coffee shops or online customers, by manually filling and 

labeling bags. The hand packers also worked alongside the packaging lines to perform 

rework, where coffee with faulty packaging was manually redirected into the packaging 

process to be packed correctly, including reloading it into the hoppers on the mezzanine. 

Besides unflavored coffee, these employees handled some flavored coffee at the hand packing 

station in the grinding/packaging room or in the adjacent hold room for rework. 

In April 2017, the grinding/packaging room was largely the same as in 2012 with six 

packaging lines and two grinders; however, a corner-seal packaging line had been installed in 

the hold room and a Super Sack filling station was installed in the main packaging area near 

the entrance to the finished good warehouse. Additionally, an enclosed grinder feeding two 

lines had been replaced with a new unenclosed, sealed grinder that fed those packaging lines 

and the Super Sack filling station. The most significant modification made to the facility since 

November 2012 was the enclosure of the entire mezzanine level of the grinding/packaging 

room; it was separate from the other production spaces. Two new supply air ducts were added 

along the south wall; each duct had two openings, one high and one low. Two exhaust fans 

for the space were located in the roof near the northern end of the space.

Flavored Coffee Production Room

During our initial walkthrough in July/August 2012, flavoring occurred in small batches. 

Initially, freshly roasted coffee beans sat overnight to off-gas. The next day a mixer or 

flavor specialist scooped whole roasted coffee beans from a hopper into a bin on wheels and 

transported it to one of two flavor mixing stations. A mixer ran a flavoring station used to 

make hazelnut coffee, and a flavor specialist ran the other mixing station which made smaller 

batches of flavored coffee including cinnamon twist, cinnamon bun, cinnamon almond 

macaroon, blueberry cobbler, butter pecan, butterscotch, butter toffee, coconut cream, Swiss 

chocolate almond, white chocolate mousse, eggnog, gingerbread snap, hazelnut, French 

caramel cream, French vanilla, Irish cream, praline & cream, pumpkin, spiced butter rum, 

and others. 

At each mixing station, the mixer or flavor specialist scooped roasted coffee beans into open 

barrels mounted on a rotating rack. The mixer or flavor specialist then weighed the liquid 

flavoring on a small scale on an open bench top. Some flavorings were stored in the flavoring 

room in large barrels and pumped into one-gallon containers. Most flavorings were stored in 

three to five-gallon containers.

After a flavoring was weighed, the mixer or flavor specialist carried the open container to 

a mixing station and poured the flavoring into one of the rotating barrels of roasted coffee 

beans and repeated this process until all coffee beans were flavored. The employee stood 

nearby to monitor the process, break up clumps of coffee, and make sure the flavoring was 
Health Hazard Evaluation Report 2012-0170-3372 Page 11

evenly distributed. When mixing was complete, they manually emptied the barrels into large 

storage containers on wheels. The employee repeated this process until the ordered amount 

of flavored coffee had been completed; for the larger orders, this process was repeated for 

the duration of the shift. After the coffee beans were flavored, they were manually dumped 

into an opening in the floor to be transported via an enclosed bucket elevator to a hopper on 

the flavoring mezzanine for a 12-hour off-gassing period before grinding or packaging. After 

the beans were ground, they were transported back up to a hopper on the mezzanine for an 

additional 12-hour off-gassing before packaging. 

When ready to be bagged, the flavored whole bean or ground coffee dropped to one of 

two packaging machines in the flavoring room that filled bags and placed them on a 

conveyer belt. Flavored coffee was packaged in non-valved bags so that the flavoring did 

not contaminate other coffee. Packers and helpers placed cardboard boxes at the end of the 

packaging lines to catch bags from the conveyer belt. Once full, they taped the cardboard 

box tops and stacked the boxes on pallets. Using a forklift, a material handler transported 

the pallets to the finished products warehouse. Occasionally, hand packers manually packed 

small orders of flavored coffee and performed re-works where coffee with faulty packaging 

was manually redirected into the packaging process.

In August 2012, the company changed the layout of the flavoring room. Small batches 

of flavored coffee continued to be prepared as previously described, while processing of 

larger batches of hazelnut coffee became more automated. In this new process, the coffee 

was roasted and ground with no off-gas periods afterwards, and then the ground coffee was 

flavored in a large batch automated mixer that pumped the flavoring from a carboy next to 

the machine and injected it directly onto the ground coffee. The flavored coffee was then 

transported up to the mezzanine via an enclosed bucket elevator to a hopper for a 12-hour 

off-gassing prior to packaging. The manual tasks included dumping the beans into an opening 

in the floor to be ground and filling the carboy with the appropriate flavoring.

In April 2017, the layout of the flavoring room and the associated local exhaust ventilation 

systems were fundamentally the same as in November 2012.

Quality Control Room

Quality control technicians performed quality checks on the coffee during all steps of 

the production process. The quality control room equipment included a sieve shaker, 

scales, small grinders, stovetop, small roasting machine, coffee brewers, water tank, and a 

machine to test bags for valve integrity. Throughout their shift, quality control technicians 

intermittently left the quality control room for minutes at a time to go to other parts of the 

plant (such as the greens warehouse, grinding/packaging room, and flavoring room) to 

retrieve samples of coffee for quality checks. Throughout the day, quality control technicians 

performed a procedure called cupping. Cupping is a systematic method for investigating the 

nature of green coffee beans and includes smelling and inspecting the green coffee beans, 

roasting and grinding samples, smelling during the roasting and grinding, testing the aroma, 

and tasting the coffee. 
Page 12 Health Hazard Evaluation Report 2012-0170-3372

For flavored coffee, quality control technicians performed some quality checks, including 

opening flavored coffee bags, weighing the coffee on a scale, and brewing and tasting the 

coffee. These activities were done in the break room (located in the production support office 

area) instead of the quality control room, to prevent contaminating the non-flavored coffee. 

Maintenance Rooms

Adjacent to the roasting room and separated by a 3/4-height wall was a maintenance shop 

where mechanical and welding work was performed. Additionally, a small maintenance room 

was located behind the maintenance supervisor’s office in the production support office area. 

Offices

The non-production offices were located in a two-story section of the building near the 

reception entrance to the plant. Several production support offices were located within the 

larger production area, adjacent to the grinding and packaging operation for unflavored 

coffee. The production support offices were typical room height while the grinding/packaging 

room averaged over 30 feet tall. Between the quality control room and reception area was 

a room used to train staff and demonstrate coffee brewing equipment and company coffee 

products to customers.

Worker Mobility

Many employees did not spend all their time in their company-designated department (e.g., 

nonproduction offices, production support offices, warehouse, roasting room, grinding/

packaging room, flavoring room, quality control room) since their job duties entailed 

spending time in various areas of the plant. For example, the plant manager, production 

supervisors, and maintenance staff often entered multiple areas of the plant. Material 

handling and inventory staff entered the production areas to move things or check inventory. 

The housekeeper cleaned nonproduction offices, the production support areas, and the 

warehouse office. Quality control technicians obtained samples in the warehouse, grinding/

packaging room, and flavoring room or dealt with paperwork in different areas of the plant. 

Some nonproduction office employees reported giving tours of the entire plant or entering 

the different production or production support areas to check paperwork or get questions 

answered. Some participants reported helping in other departments, for example, with 

reworks or hand packing in the flavoring room or operating the packaging machines in the 

grinding/packaging room or flavoring room. 

Cleaning Activities

In November 2012, various cleaning techniques were used throughout the production areas. 

Employees used brooms to sweep the production floor, wet or dry wipes on table tops and 

equipment surfaces, and compressed air to remove coffee bean dust from surfaces and 

equipment. The facility had a wash station equipped with a commercial dishwasher that 

washed buckets and containers for reuse. In response to a NIOSH recommendation after the 

2012 visit, the facility reduced the use of compressed air for cleaning and placed industrial 

vacuums throughout the production spaces for use in cleaning tasks.
Health Hazard Evaluation Report 2012-0170-3372 Page 13

In April 2017, wet/dry vacuum cleaners (Dayton Model 135020) were stationed along beams 

throughout the production area for cleaning to limit the use of compressed air. Despite the 

addition of the vacuums, many cleaning tasks were still observed to be completed using 

brooms, dust mops, or compressed air.

Personal Protective Equipment

Employees in the production areas wore steel toe shoes, safety glasses/goggles, companyprovided uniforms, hair covers, and beard covers (if applicable). Hearing protection (foam 

ear plugs) was available but not required. Mixers and flavor specialists wore rubber aprons, 

gloves and face shields when measuring or pouring flavorings. They also wore face shields at 

the time of the NIOSH walkthrough and medical survey.

At the NIOSH initial walkthrough in July/August 2012, N95 filtering facepiece respirators 

were available but not required. At the NIOSH medical survey in September 2012, the 

flavoring specialists and mixers sometimes wore half-mask respirators with organic 

vapor/particulate cartridges in the flavoring room. N95 filtering facepiece respirators (for 

particulates but not organic vapors) were available but not required for other staff. At the 

time of the NIOSH industrial hygiene survey in November 2012, individuals who worked 

in the flavoring room or entered the flavoring room wore full-face powered air-purifying 

respirators (PAPRs) with an assigned protection factor (APF) of 1000 and NIOSH-certified 

organic vapor/particulate cartridges. N95 filtering facepiece respirators were available but not 

required in other production areas.

During our April 2017 visit, employees were required to wear a half-face air-purifying 

respirators with NIOSH-certified organic vapor/particulate cartridges in the flavoring room, 

packaging room mezzanine, while filling the hopper on the corner-seal packaging machine, 

when working inside grinder enclosures, and when doing rework activities.

Methods 

We conducted an initial walkthrough at the coffee roasting, flavoring, and packaging facility 

in July/August 2012. We returned for a medical survey in September 2012. In November 

2012 and April 2017, we conducted industrial hygiene surveys and ventilation assessments. 

We had the following objectives for the health hazard evaluation:

1. Measure employees’ exposure to diacetyl, 2,3-pentanedione, and 2,3-hexanedione 

during coffee processing;

2. Identify process areas or work tasks associated with emissions of diacetyl, 

2,3-pentanedione, and 2,3-hexanedione;

3. Measure levels of TVOCs, CO, CO2, and inhalable dust throughout the facility;

4. Assess ventilation systems and their effect on exposure levels;

5. Determine if employees had mucous membrane, respiratory, or systemic symptoms 

and the proportion of those symptoms that were work-related or aggravated by work;
Page 14 Health Hazard Evaluation Report 2012-0170-3372

6. Determine if employees had abnormal lung function; 

7. Determine total and specific Immunoglobulin E and G; 

8. Compare employees’ prevalence of lower respiratory symptoms and healthcare 

provider-diagnosed asthma to expected levels based on general population values.

9. Evaluate company-provided spirometry and assess changes in lung function over 

time.

We provided seven interim reports with recommendations to the company following our 

visits. 

Initial Walkthrough

We held an opening and closing meeting with management and employees, toured the 

facility, collected bulk samples of flavorings and evacuated canister air samples, and had 

informal interviews with employees. 

Industrial Hygiene Surveys

Sampling Times for Alpha-Diketones 

We designed the sampling strategy to assess full-shift exposures and to identify tasks and 

processes that were the greatest contributors to employee exposure to alpha-diketones. For 

diacetyl, 2,3-pentanedione, and 2,3-hexanedione, air samples were collected over seconds, 

minutes, and hours. Samples collected over hours can help determine average concentrations 

that can be compared to the NIOSH RELs for diacetyl and 2,3-pentanedione. These average 

concentrations might not tell us about short-term peak exposures that could be relevant to 

respiratory health, particularly when tasks are repeated multiple times per day. Therefore, 

during certain tasks, we collected air samples over several minutes. We also conducted 

instantaneous sampling over seconds to help identify point sources of alpha-diketones. 

Air Sampling and Analysis Using Modified Occupational Safety and Health Administration 

(OSHA) Methods

There are three validated OSHA Analytical Methods used to analyze samples for alphadiketones in air. OSHA Method 1013 is used for determining low parts per million (ppm) 

concentrations of diacetyl [OSHA 2008a]. In response to the need for longer sampling time 

periods with a lower limit of detection or reliable quantitation limit, OSHA Method 1012 was 

validated for parts per billion (ppb) concentrations of diacetyl [OSHA 2008b]. OSHA Method 

1016 is used to measure 2,3-pentanedione concentrations [OSHA 2010].

We collected personal and area air samples for diacetyl and 2,3-pentanedione on silica gel 

sorbent tubes during both industrial hygiene surveys over multiple days. April 2017 samples 

were also analyzed for 2,3-hexanedione. The samples were collected and analyzed according 

to modified OSHA Methods 1013/1016 [OSHA 2008a; OSHA 2010; LeBouf and Simmons 

2017]. In accordance with the two methods, two glass silica gel sorbent tubes were connected 

by a piece of tubing and inserted into a protective, light-blocking cover. The tubes were 
Health Hazard Evaluation Report 2012-0170-3372 Page 15

connected in series to a sampling pump pulling air through the tubes at a flow rate of 50 

milliliters per minute (mL/min). The sampling setup was attached to an employee’s breathing 

zone or placed in an area basket in locations throughout the facility. For full-shift sampling, 

we collected two consecutive 3-hour samples and calculated the TWA concentration from the 

two samples, assuming that the total 6-hour monitoring results reflected a full work shift (8-

hour) TWA exposure. This is a more conservative approach than the alternative assumption 

of no exposure during the last two hours of the shift. We refer to these samples as “full-shift 

samples” throughout this report. We also collected short-term, task-based samples in the 

same manner with a sampling pump flow rate of 200 mL/min, as detailed in OSHA Methods 

1013/1016 [OSHA 2008a; 2010]. 

Samples from the first industrial hygiene survey (November 2012) were analyzed by Bureau 

Veritas North America (BVNA; Novi, MI). The samples were chemically desorbed using 

two milliliters (mL) of 95% ethanol:5% water (ACS spectrophotometric grade), shaken 

for 60 minutes, and subsequently analyzed using an HP 5890 gas chromatograph with a 

flame ionization detector (GC/FID) (Agilent Technologies, Inc.). The sample extracts were 

subsequently derivatized according to a modified OSHA Method 1012 to increase sensitivity 

[OSHA 2008b]. The derivatized extracts were analyzed using an HP 5890 GC with an 

electron capture detector (GC/ECD) (Agilent Technologies, Inc.). For the November 2012 

visit, we reported results from the validated method with the greatest sensitivity: OSHA

Method 1012 for diacetyl and OSHA Method 1016 for 2,3-pentanedione. 

Samples from the second industrial hygiene survey (April 2017) were analyzed in the NIOSH 

Respiratory Health Division’s Organics Laboratory. The samples were extracted in 95% 

ethanol:5% water containing 3-pentanone as an internal standard, shaken for 60 minutes, and 

subsequently analyzed using an Agilent 7890/7001 GC/mass spectrometer (GC/MS) system. 

The mass spectrometer operated in selected ion monitoring mode for increased sensitivity 

compared to the traditional FID used in OSHA Methods 1013/1016 [LeBouf and Simmons 

2017].

A limit of detection (LOD) is the lowest mass that an instrument can detect above 

background and is a criteria used to determine whether to report a result from a sample. The 

LODs decreased between the first and second visit. The LODs for the first industrial hygiene 

survey were 0.05 micrograms per sample (μg/sample) for diacetyl (OSHA Method 1012) 

and 0.20 μg/sample for 2,3-pentanedione (OSHA Method 1016). These equate to 1.6 ppb 

for diacetyl and 5.4 ppb for 2,3-pentanedione for a typical full-shift TWA air sample but will 

vary depending on the volume of air collected during the sampling period.

The limit of quantitation (LOQ) is the lowest mass that can be reported with acceptable 

precision, and there is greater confidence in the reported result if it is above the LOQ. The 

LOQs for the first industrial hygiene survey were 0.18 micrograms per sample (μg/sample) 

for diacetyl (OSHA Method 1012) and 0.63 μg/sample for 2,3-pentanedione (OSHA Method 

1016). These equate to 5.7 ppb for diacetyl and 17.1 ppb for 2,3-pentanedione for a typical 

full-shift TWA air sample but will vary depending on the volume of air collected during the 

sampling period. 
Page 16 Health Hazard Evaluation Report 2012-0170-3372

The LODs for the second industrial hygiene visit in April 2017 were 0.01 μg/sample for 

diacetyl, 2,3-pentanedione, and 2,3-hexanedione. These equate to 0.32 ppb for diacetyl, 0.27 

ppb for 2,3-pentanedione, and 0.24 ppb for 2,3-hexanedione for a typical full-shift TWA air 

sample. The LOQs were 1.1 ppb for diacetyl, 0.90 for 2,3-pentanedione, and 0.79 ppb for 

2,3-hexanedione. 

The LODs for task samples are generally higher than typical LOD values for full-shift 

samples since the air volumes collected during task samples were lower. When the values 

presented in the report were from samples below the LOD they are denoted by a “<” symbol. 

Air Sampling and Analysis Using Evacuated Canisters

We collected personal and area air samples and instantaneous task-based and source air 

samples for VOCs, including diacetyl and 2,3-pentanedione using evacuated canisters during 

the walkthrough. In November 2012, full-shift personal and area samples were collected and 

analyzed for diacetyl and 2,3-pentanedione. In April 2017, we collected instantaneous air 

samples before and after the work shift to determine if air concentrations of alpha-diketones 

(diacetyl, 2,3-pentanedione, and 2,3-hexanedione) changed over the course of a work shift. 

The evacuated canister sampling setup consisted of a 450-mL evacuated canister equipped 

with either a restricted flow controller set at a 15-minute, 6-hour, or 9-hour duration, or an 

instantaneous flow controller designed for a short sampling duration (less than 30 seconds). 

Instantaneous samples were taken by opening the evacuated canister to grab a sample of 

air to help identify point sources of alpha-diketones. For task-based air samples, a NIOSH 

employee placed the inlet of the flow controller in an employee’s personal breathing zone 

as they performed their work task to replicate exposure. For source air samples, a NIOSH 

employee placed the inlet of the flow controller directly at the source of interest. 

The canister air samples were analyzed using a pre-concentrator/GC/MS [LeBouf et al. 2012; 

NIOSH 2018]. For the walkthrough and first industrial hygiene visit, the typical LODs were 

2.7 ppb for diacetyl, and 3.3 ppb for 2,3-pentanedione, but LODs for individual samples were 

dependent on the pressure inside each canister after the samples have been collected, and 

they may be higher or lower than these typical values. The typical LOQs were 8.9 ppb and 

10.9 ppb for diacetyl and 23-pentanedione, respectively. For the second industrial hygiene 

survey in April 2017, typical LODs were 0.78 ppb for diacetyl, 1.1 ppb for 2,3-pentanedione, 

and 1.9 ppb for 2,3-hexanedione. The typical LOQs were 2.6 ppb, 3.6 ppb, and 6.3 ppb for 

diacetyl, 2,3-pentanedione, and 2,3-hexanedione, respectively. 

Inhalable Dust Sampling (November 2012 Only)

We collected personal and area air samples for inhalable dust using the Institute of 

Occupational Medicine (IOM) sampler (SKC Inc., Eighty Four, PA) loaded with a preweighed 25-mm polyvinyl chloride filter with air pulled through the filter at a flow rate of 2.0 

liters per minute for a minimum of 6 hours to achieve a TWA sample. Inhalable dust samples 

were collected and weighed following NIOSH Method 0500 [NIOSH 1994]. The LOD for 

the gravimetric method was 200 micrograms per sample (μg/sample), which corresponds to 

approximately 0.3 milligrams per cubic meter (mg/m3) for typical samples. The actual LOD 

for individual samples varies, depending on actual sampling duration. 
Health Hazard Evaluation Report 2012-0170-3372 Page 17

Bulk Sampling and Headspace Analysis

We used 50-mL sterile polypropylene centrifuge tubes to collect four liquid flavoring 

samples during the initial walkthrough. Bulk samples of nine liquid flavorings were collected 

during the second industrial hygiene survey. For headspace analysis of alpha-diketones, we 

transferred 1 mL of liquid bulk material into a sealed 40-mL amber volatile organic analysis 

vial and let it rest for 24 hours at room temperature (70°F) in the laboratory. Then 2 mL of 

headspace air was transferred to a clean 450-mL canister and pressurized to approximately 

1.5 times atmospheric pressure. Using the canister analysis system, the concentrations were 

calculated in ppb of analytes in the headspace as an indicator of emission potential. 

Real-time Air Sampling

We collected real-time area samples for TVOCs and total dust concentrations throughout the 

facility during November 5-8, 2012. The real-time TVOC data were collected using RAE 

Systems ppbRAE monitors (models 3000 and 7240, RAE Systems Inc., San Jose, CA) which 

contain photoionization detectors with 10.6 electron volt lamps. They are a non-specific 

detector that will efficiently respond to any VOC with an ionization potential less than 10.6 

electron volts. The ppbRAE monitors were calibrated with isobutylene, so all reported results 

are isobutylene-equivalents. Real-time total dust measurements were collected using TSI 

DustTrak DRX aerosol monitors (model 8533, TSI Inc., Shoreview, MN). Since we had 

a limited number of real-time instruments, we rotated them in the area sampling baskets 

distributed throughout the facility. We occasionally removed the TVOC monitors from the 

area baskets to more closely monitor a process or task.

During April 11-13, 2017, we used RAE Systems (San Jose, CA) ppbRAE 3000 monitors 

or Tiger VOC detector monitors (ION Science, Stafford, TX) to measure concentrations 

of TVOCs in the air during both visits. Both instruments use non-specific photoionization 

detectors that respond to chemicals with ionization potentials below the energy of the lamp. 

These monitors were used to identify areas where coffee could be releasing VOCs. Areas 

where higher concentrations of TVOCs were measured may benefit from further sampling to 

characterize specific exposures to alpha-diketones. 

During both visits we also collected real-time measurements of temperature and relative 

humidity (RH) using TSI Incorporated (Shoreview, MN) VelociCalc Model 9555-X MultiFunction Ventilation Meters equipped with Model 982 IAQ probes. In April 2017, we also 

collected real-time measurements of CO2 and CO using the same equipment.

Ventilation Assessments

In November 2012, we collected physical measurements of all ducts, ventilation openings 

and rooms with a standard tape measure or a Zircon (Campbell, CA) LaserVision DM 200 

laser tape measure. Air flow measurements of supply vents and exhaust outlets were taken 

using an Accubalance Plus Model 8373 Air Capture Hood (TSI Incorporated, Shoreview, 

MN) or a TSI VelociCalc Plus Model 8324 Rotating Vane Anemometer, depending on which 

was most appropriate for the ventilation component being measured. The complete set of 

ventilation measurements allowed the estimation of volumetric flow rates in cubic feet per 
Page 18 Health Hazard Evaluation Report 2012-0170-3372

minute (cfm) into and out of each area. A Ventilation Smoke Tube Kit, Catalog #458481 

(MSA, Pittsburgh, PA), was used to visualize airflow patterns in the plant, particularly in 

and around local exhaust ventilation hoods, to investigate whether contaminant sources 

were effectively captured and removed by the ventilation system. Differential pressure 

measurements between adjacent spaces were taken under various ventilation scenarios using 

an Energy Conservatory DG-500 Pressure Gauge (Minneapolis, MN).

In August 2017, the ventilation assessment was repeated using an Alnor (TSI Incorporated, 

Shoreview, MN) Model RVA501 Air Velocity Meter in place of the Accubalance Plus Model 

8373 Air Capture Hood and TSI VelociCalc Plus Model 8324 Rotating Vane Anemometer.

Informal Interviews during Walkthrough Visit

A NIOSH medical officer conducted voluntary, private individual interviews with 22 

employees about their work history and health concerns. A NIOSH staff member fluent in 

Spanish assisted during the interviews, as needed.

NIOSH Medical Survey

Participants 

We invited all current employees to participate in the medical survey at the workplace on 

September 10-13, 2012, including on-site temporary workers. Thirteen former workers, 

including the five who were diagnosed with obliterative bronchiolitis, participated in the 

medical survey at the local health department on September 14, 2012. Participation was 

voluntary; written informed consent approved by the NIOSH Institutional Review Board was 

obtained from each individual at the time of testing. The survey included a medical and work 

history questionnaire, spirometry, administration of bronchodilator or mannitol challenge 

test, tests for carbon monoxide diffusing capacity and alveolar volume, and blood tests for 

immune responsiveness. 

Questionnaire 

We used an interviewer-administered computerized questionnaire to ascertain symptoms 

and diagnoses, work history with this company and other coffee or flavoring companies, 

and cigarette smoking history. Questions on respiratory health were derived from three 

standardized questionnaires, the European Community Respiratory Health Survey (ECRHS) 

[Burney et al. 1994; ECRHS 2014], the American Thoracic Society (ATS) adult respiratory 

questionnaire (ATS-DLD-78) [Ferris 1978], and the Third National Health and Nutrition 

Examination Survey (NHANES III) questionnaire [CDC 1996], and were supplemented 

with respiratory, dermatological, and systemic symptom questions. We had four bilingual 

interpreters that assisted with Spanish translation of consent, questionnaires, and instructions 

during medical testing.

Spirometry 

The purpose of the spirometry test was to determine a person’s ability to move air out 

of their lungs. Test results were compared to expected normal values. The test included 

three measurements or calculations: 1) forced vital capacity (FVC) (total amount of air the 

participant can forcefully blow out after taking a deep breath), 2) FEV1 (amount of air the 
Health Hazard Evaluation Report 2012-0170-3372 Page 19

participant can blow out in the first second of exhaling), 3) mid‐expiratory flow (FEF25–75) 

(forced expiratory flow between 25% and 75% of exhaled volume), and 4) ratio of FEV1 to 

FVC. We used ATS criteria for acceptability and repeatability [Miller et al. 2005]. 

We used a volume spirometer (dry rolling seal spirometer) to measure exhaled air volume 

and flow rates. We used equations for predicted values and lower limits of normal derived 

from NHANES III data to define abnormal spirometry [Hankinson et al. 1999]. We defined 

obstruction as an FEV1/ FVC ratio less than the lower limit of normal with FEV1 less than 

the lower limit of normal; restriction as a normal FEV1/FVC ratio with FVC less than the 

lower limit of normal; and mixed obstruction and restriction as having FEV1, FVC, and 

FEV1/FVC ratio all less than the lower limit of normal. We used the FEV1 percent predicted 

to categorize such abnormalities as mild, moderate, moderately severe, severe, or very severe 

[Pellegrino et al. 2005]. We defined a low FEF25–75 as less than the lower limit of normal. 

Bronchodilator Reversibility Testing for Spirometry

If a participant had abnormal spirometry, we repeated the test after the participant received 

a bronchodilator inhaler medication (i.e., albuterol), which can open the airways in some 

individuals (e.g., asthmatics). We defined reversibility (improvement) as increases of at least 

12% and 200 mL for either FEV1 or FVC after bronchodilator administration. 

Diffusing Capacity and Alveolar Volume (DLCO) 

The purpose of DLCO test is to determine how well a person’s lungs transfer oxygen. 

Diffusing capacity is decreased in persons with emphysema and in persons with scarring or 

inflammatory diseases of the air sacs of the lung. The purpose of the alveolar volume test 

is to estimate the amount of air in a person’s lungs after taking a deep breath. We measured 

DLCO using the single breath technique with helium as the tracer gas. We used the ATS 

criteria for acceptability and repeatability [MacIntyre et al. 2005]. We compared the alveolar 

volume to reference values generated from a stratified random sample of the general 

population of an entire state [Miller et al. 1983]. We defined DLCO below the lower limit of 

normal as low diffusing capacity. From the same test, we estimated total lung capacity using 

the calculated alveolar volume. 

Mannitol Challenge Test for Bronchial Hyperresponsiveness 

We used mannitol challenge testing to examine bronchial hyperresponsiveness in 

employees with normal spirometry. This is a test that is frequently abnormal in persons with 

uncontrolled asthma, who may have normal lung function between asthma attacks but whose 

airways are sensitive and can narrow in reaction to irritants and allergens. We measured the 

FEV1 following successive doses of mannitol (0, 5, 10, 20, 40, 80, 160, 160, 160 milligrams 

(mg). We asked subjects to exhale completely before taking a controlled deep inspiration 

from the device, to hold their breath for 5 seconds, and then to exhale through the mouth. 

Sixty seconds after inhalation of the 0 mg capsule, the FEV1 was measured in duplicate. 

The highest of these values was taken as the baseline FEV1 and used to calculate the target 

FEV1 value that indicated a 15% fall in response to the mannitol challenge. The interpolated 

provocative dose causing a 15% fall in FEV1 was expressed as a PD15 [Pharmaxis, Inc. 

2012]. The procedure outlined for the 0 mg capsule was repeated for each dose step until a 
Page 20 Health Hazard Evaluation Report 2012-0170-3372

15% fall in FEV1 was achieved (or a 10% fall between consecutive doses), or the cumulative 

dose of 635 mg had been administered. A value above 635 mg was considered normal. A 

value from 156 mg to 635 mg was considered mildly increased airway sensitivity. A value 

from 36 mg to 155 mg was considered moderately increased airway sensitivity. A value of 

35 mg or less was considered severely increased airway sensitivity [Anderson and Brannan 

2003; Pharmaxis, Inc. 2012].

Determination of Total and Specific Immunoglobulin G and E 

We tested participants’ blood to determine if they had antibodies that reacted to coffee, 

green coffee beans, or castor beans. There are different classes of antibodies including 

immunoglobulin G (IgG) and immunoglobulin E (IgE). The presence of IgG antibodies 

specific to coffee, green coffee bean, or castor bean antigens is a marker of exposure to that 

specific antigen. The level of specific IgG usually reflects the amount of exposure to that 

antigen. IgE is considered the allergic antibody. Adults who have allergies tend to have an 

elevated total IgE blood level, but this does not provide information as to the specific allergen 

that a person may be allergic to. We examined whether or not participants had IgE antibodies 

in the blood that reacted to coffee, green coffee bean, or castor bean allergens.

We collected 20 mL of blood by venipuncture from each participant. The serum was 

separated for quantitative measurement of total IgE, specific IgE, and specific IgG antibodies. 

Samples were analysed for total IgE and specific IgG and IgE by fluoroenzymeimmunoassay 

using the ImmunoCAP100 (Phadia AB, Uppsala, Sweden). Total IgE serum levels equal to 

or greater than 100 kilounits per liter (kU/L) indicate an atopic status (tendency to develop 

allergic diseases such as atopic dermatitis, hay fever, and asthma); total IgE serum levels 

less than 100kU/L indicate a non-atopic status. Specific IgE and specific-IgG were measured 

using green coffee (k70), coffee (Rf221), and castor bean (k71) allergens/antigens covalently 

coupled to ImmunoCAPs (Phadia AB). Sensitivity to a specific allergen was considered 

positive when IgE titers exceeded 0.35 kUA/L. (The “A” represents the amount of specific 

IgE antibody present in the blood.) Antibody level to antigen-specific IgG was measured as 

milligrams of antigen specific-antibodies per liter (mgA/L).

Index of Suspicion for Possible Lung Disease

We developed an index of suspicion for possible obliterative bronchiolitis using questionnaire 

data and medical test results. In participants who reported ever going into the grinding/

packaging room or the flavoring room, indications for possible obliterative bronchiolitis 

were the following: shortness of breath on exertion (a report of shortness of breath walking 

with people of his/her own age on level ground; of having to stop for breath when walking 

at his or her own pace on level ground; or having to stop for breath after walking about 

100 yards or after a few minutes), cough, chest wheeze/whistling, regular trouble with 

breathing, abnormal spirometry, decreased diffusing capacity, or decreased alveolar volume. 

We included these symptoms and abnormalities because medical literature documents that 

spirometry, diffusing capacity, and lung volumes can be insensitive for biopsy-confirmed 

obliterative bronchiolitis, and many cases have normal spirometry or have abnormalities 

in any pattern [Ghanei et al. 2008; King et al. 2011; Markopoulou et al. 2002]. In addition, 
Health Hazard Evaluation Report 2012-0170-3372 Page 21

pulmonary function abnormalities in flavoring-exposed workers may not be accompanied by 

reported symptoms [Kreiss et al. 2002]. 

For an index of suspicion for possible work-related asthma (including occupational asthma 

and work-exacerbated asthma), we considered both asthma arising during employment and 

pre-employment asthma with exacerbation related to work. Indications for possible asthma 

were the following: awoken by an attack of shortness of breath in the past 12 months; 

awoken with a feeling of tightness in the chest in the past 12 months; cough; chest wheeze/

whistling in the past 12 months; regular trouble breathing; obstruction on spirometry with 

a bronchodilator response and the presence of asthma-like symptoms; or positive response 

to mannitol with the presence of asthma-like symptoms. Prior physician diagnoses of 

respiratory disorders were also taken into consideration. If an asthma indication was present, 

a positive IgE response to coffee, green coffee beans, or castor beans was considered 

evidence for occupational asthma associated with any of these antigens. 

Coffee Facility Occupational Health Provider Spirometry 

The coffee roasting, flavoring, and packaging facility contracted an occupational health 

provider to perform spirometry as part of their medical surveillance program. We assessed 

the occupational health provider spirometry data collected in October 2014 and October 

2015 for quality and excessive declines in FEV1 or FVC between tests for employees 

who completed more than one spirometry test, including NIOSH spirometry data from the 

September 2012 medical survey. 

We classified the spirometry tests using a grading scheme based on the acceptability and 

repeatability criteria recommended by the American Thoracic Society [Miller et al. 2005]. 

Trials were considered to have acceptable quality for measurement of FEV1 if they were free 

of technical errors at the start of the trial (including large extrapolated volume and cough in 

the first second), and there was evidence of adequate inspiration. For measurement of FVC, 

trials also were required to show evidence of adequate expiration and that end-of-test criteria 

were satisfied to be considered of acceptable quality.

Each test received a separate quality grade for FEV1 and FVC. Any trial deemed not 

technically acceptable was not considered when grading the quality of the test session. We 

assigned FEV1 quality grade A if a test session contained at least three acceptable trials, and 

the highest two values were repeatable within 100 mL. FEV1 grade B was assigned if the 

session contained at least two acceptable trials, and the highest two values were repeatable 

within 150 mL. FEV1 grade C was assigned if the session contained at least two acceptable 

trials, and the highest two values were within 250 mL. Similarly, we assigned FVC quality 

grade A if a test session contained at least three trials, and the highest two values were 

repeatable within 100 mL. FVC grade B was assigned if the session contained at least two 

acceptable trials, and the highest two values were repeatable within 150 mL. FVC grade C 

was assigned if the session contained at least two acceptable trials, and the highest two values 

were repeatable within 250 mL. Only tests with A, B or C quality grades in both FEV1 and 

FVC were interpreted.
Page 22 Health Hazard Evaluation Report 2012-0170-3372

Longitudinal Changes in Spirometry 

For medical survey participants that had company-provided spirometry results, we compared 

the results of NIOSH spirometry tests performed and the most recent company-provided 

spirometry test to assess their change in FVC and FEV1. Excessive decline in FEV1 or FVC 

was defined as a 15% or more decrease in FEV1 or FVC, after accounting for the expected 

loss due to aging, between two spirometry tests [Pellegrino et al. 2005; Townsend and 

Occupational and Environmental Lung Disorders Committee 2011]. We mailed health hazard 

evaluation participants letters (in English and Spanish, if applicable) regarding their change 

in FVC and FEV1 from the NIOSH spirometry testing and the most current companyprovided spirometry testing. We recommended participants provide that information to 

their physicians. Of the employees that did not have NIOSH spirometry testing but had two 

company-provided spirometry tests, we compared the results between the two companyprovided spirometry tests to evaluate for excessive declines in FEV1 or FVC.

Statistical Analysis 

Industrial Hygiene Survey and Ventilation Assessment

We performed analyses using Excel (Microsoft®, Redmond, WA) and SAS version 9.4 (SAS 

Institute Inc., Cary, NC). We created summary statistics by work area location, job title, and 

task. When the values presented in the report are from samples below the LOD they are 

denoted by a “<” symbol.

Medical Survey

Based on the participants’ questionnaire responses, we determined the job title and 

department they were primarily assigned to at the time of the survey and during past 

jobs at the facility. Worker mobility suggested that classifying employees into similar 

exposure groups based on job title or company-designated department would result in 

substantial misclassification of exposure and make evaluation of potential exposure-response 

relationships difficult. Since we had questionnaire data regarding whether employees spent 

time in the grinding/packaging room or flavoring room during their current or past jobs 

at the coffee roasting, flavoring, and packaging facility, we used that index of exposure 

for analyses. We also created exposure variables using assignment to the roasting room 

combined with reports of entering the roasting room for the current and past jobs.

We compared participants’ prevalences of symptoms and spirometric obstructive and 

restrictive abnormalities and abnormal FEF25-75 to expected prevalences of a sample of the 

general population reflected in the NHANES III, adjusting for gender, race, age (age ≤ 39 

and ≥ 40), and smoking categories (ever/never). For restrictive pattern on spirometry, we also 

adjusted for body mass index (BMI).

 

We conducted analyses using SAS version 9.3 and 9.4 (SAS Institute, Cary, North Carolina). 

We ran linear regressions using the GLM procedure on percent predicted FEV1, FVC, 

FEF25-75, DLCO, and alveolar volume, and on the FEV1/FVC ratio in relation to currently 

and ever having any work time in the grinding/packaging room and flavoring room, as 

well as for currently and ever having any work time in the roasting room. We used logistic 

regression models to evaluate prevalence of upper and lower respiratory symptoms, 
Health Hazard Evaluation Report 2012-0170-3372 Page 23

sinus symptoms, and eye irritation in relation to currently having worked in the grinding/

packaging room and/or flavoring room, and currently having worked in the roasting room. 

The comparison group for working in grinding/packaging room and/or flavoring room was 

composed of participants who worked in neither. The models for symptoms and the FEV1/

FVC ratio were adjusted for age and smoking pack-years, while the percent predicted lung 

function parameter models were adjusted for smoking pack-years. We chose a probability 

of less than or equal to 0.05 as a criterion for statistical significance. In view of the small 

size of the worker population and the curtailed distribution of exposure indices, we report a 

probability between greater than 0.05 and less than or equal to 0.1 as marginally significant.

Results

All results tables are in Appendix A.

Walkthrough Visit – July/August 2012

Headspace analyses of flavorings collected during the walkthrough showed that 

2,3-pentanedione existed in higher concentrations than diacetyl in three of the four samples 

(Table A1).

Canister sample results from the walkthrough are shown in Table A2. We collected 14 

evacuated canister samples; eight personal samples and six area samples. All personal 

samples were collected on flavoring room employees. Three-hour TWA personal sample 

concentrations in the flavoring room ranged from 160 ppb to 260 ppb diacetyl and 110 ppb to 

570 ppb 2,3-pentanedione, and 13 ppb to 90 ppb 2,3-hexanedione. An instantaneous sample 

collected near a worker’s breathing zone immediately after addition of flavoring to beans 

in a tumbler measured 400 ppb diacetyl and 2,000 ppb 2,3-pentanedione. Concentrations of 

diacetyl and 2,3-pentanedione were lowest in the 15-minute samples collected in the greens 

warehouse and roasting room. A 4.5-hour sample collected in the unflavored coffee grinding/

packaging room (just outside flavoring room entrance) measured 170 ppb diacetyl and 120 

ppb 2,3-pentanedione. 

Industrial Hygiene Surveys

Personal and Area Full-shift Air Sampling Results

Modified Occupational Safety and Health Administration (OSHA) Methods

Table A3 presents the personal and area full-shift air sampling results from our first industrial 

hygiene visit in November 2012. We collected 59 personal and 111 area full-shift air samples 

over four days. Fifty-eight personal air samples (98%) were above the NIOSH REL for 

diacetyl of 5.0 ppb and 42 (71%) were above the NIOSH REL for 2,3-pentanedione of 9.3 

ppb.

Overall, employees in packaging had the highest personal exposures to diacetyl ranging from 

75.4 ppb to 166.0 ppb. Packaging employee exposures exceeded the NIOSH REL for diacetyl 

by as much as 33 times. Employees in the production area offices had the second highest 
Page 24 Health Hazard Evaluation Report 2012-0170-3372

maximum personal exposure to diacetyl of 139.5 ppb (range: 39.7 ppb – 139.5 ppb), closely 

followed by employees in flavoring with a maximum concentration of 96.3 ppb (range: 

52.6 ppb – 96.3 ppb). Employees in the flavoring room were required to wear respirators. 

Diacetyl concentrations measured in five samples taken on employees working all over the 

facility and in one sample from an employee working in all offices ranged from 49.2 ppb to 

80.1 ppb. Personal diacetyl concentrations in roasting ranged from 15.1 ppb – 40.1 ppb and 

concentrations in the quality control room ranged from 11.7 ppb – 31.3 ppb. Concentrations 

in the downstairs non-production offices, finished good warehouse, and greens warehouse 

were all below 11.7 ppb, with all but one exceeding the NIOSH REL for diacetyl of 5.0 ppb.

Employees in flavoring had the highest personal exposures to 2,3-pentanedione ranging 

from 79.6 ppb to 199.0 ppb. Flavoring room employee exposures exceeded the NIOSH 

REL for 2,3-pentanedione by as much as 21 times. Employees in packaging had the second 

highest average personal exposure to 2,3-pentanedione ranging from 17.9 ppb to 133.6 

ppb, followed by employees who worked all over the facility with exposures ranging from 

31.7 ppb to 45.0 ppb. Concentrations of 2,3-pentanedione measured in three samples taken 

on employees working in the production area offices ranged from 9.5 ppb to 44.8 ppb. 

Personal 2,3-pentanedione concentrations in roasting ranged from < 6.0 ppb to 15.8 ppb and 

concentrations in the quality control room ranged from < 5.4 ppb to 15.8 ppb. Concentrations 

in the downstairs non-production offices, finished good warehouse, and greens warehouse 

were all below the LOD.

Area sample concentrations for diacetyl inside the facility were highest in packaging and on 

the packaging mezzanine with concentrations ranging from 67.9 to 247.2 ppb diacetyl. The 

second highest concentration was found in flavoring and the flavoring mezzanine, ranging 

from 44.0 ppb to 144.0 ppb diacetyl. Concentrations in production area offices ranged from 

33.8 ppb to 93.4 ppb, followed by roasting and the roasting mezzanine with a range of 9.5 to 

50.6 ppb diacetyl.

Area sample concentrations for 2,3-pentanedione inside the facility were highest in flavoring 

(including the mezzanine), where the range was 48.7 ppb to 273.1 ppb. Second highest area 

sample concentrations were in packaging and the packaging mezzanine with results ranging 

from 23.0 ppb to 190.6 ppb). Production area offices showed a range of 9.9 ppb to 46.2 ppb 

2,3-pentanedione, followed by roasting and the roasting mezzanine showing ae range of > 

5.3 ppb – 26.8 ppb. 

Table A4 presents the personal and area full-shift air sampling results from our second 

industrial hygiene visit in April 2017. We collected 29 personal and 147 area full-shift air 

samples over three days. Twenty-eight of the 29 personal air samples (97%) exceeded the 

NIOSH REL for diacetyl of 5.0 ppb and the NIOSH REL for 2,3-pentanedione of 9.3 ppb.

Overall, the seven flavoring employees had the highest measured personal exposure to 

diacetyl, ranging from 100.3 ppb to 163.8 ppb. Employees in the flavoring room were 

required to wear respirators, so their true exposures were lower. Employees in packaging 

had the second highest exposures with concentrations ranging from 47.2 ppb to 129.3 ppb 

diacetyl. A sample on a production office employee followed with a concentration of 52.4 
Health Hazard Evaluation Report 2012-0170-3372 Page 25

ppb, then three samples on employees who worked all over the facility showed a range of 

30.6 ppb to 45.2 ppb. 

Employees in flavoring also had the highest personal exposure to 2,3-pentanedione. The 

seven flavoring employee measurements ranged from 182.7 ppb to 899.9 ppb. Employees 

in the flavoring room were required to wear respirators, so their true exposures were lower. 

Employees in the packaging room had the second highest exposures with a range of 20.5 ppb 

to 161.6 ppb 2,3-pentanedione. A sample on a production office employee followed with a 

concentration of 23.9 ppb, then three samples on employees who worked all over the facility 

showed a range of 15.8 ppb to 21.4 ppb. 

Area sampling showed flavoring and the flavoring mezzanine had the highest air 

concentrations of diacetyl, with 24 total samples ranging from 93.2 ppb to 372.0 ppb. The 

packaging mezzanine, packaging room and new packaging line (old hold room) had 48 

samples with diacetyl concentrations ranging from 32.9 ppb to 176.2 ppb. Respirator use 

was required for any employee entering the packaging mezzanine area. Fifteen samples from 

offices in the production area showed concentrations ranging from 16.2 ppb to 128.9 ppb 

diacetyl.

Area samples in flavoring and the flavoring mezzanine also had the highest air concentrations 

of 2.3-pentanedione, with 24 total samples ranging from 224.2 ppb – 2060.3 ppb and an 

average concentration of 636.1 ppb on the lower level and 1553.0 ppb on the mezzanine. 

The packaging mezzanine, packaging and new packaging line (old hold room) had 48 

samples with 2,3-pentanedione concentrations ranging from 23.0 ppb – 124.1 ppb. Average 

area sample concentrations in those areas showed the packaging mezzanine with the 

highest (77.0 ppb) followed by packaging (67.0 ppb), then the new packaging line (old 

hold room) with 63.1 ppb 2.3-pentanedione. Fifteen samples from offices in the production 

area showed concentrations ranging from 8.0 ppb – 98.1 ppb with an average of 40.8 ppb 

2.3-pentanedione.

Nineteen of the 29 personal air samples were above the LOD for 2,3-hexanedione; of those 

above LOD, flavoring room employees had the highest concentrations, ranging from below 

LOD to 15.7 ppb. The flavoring and flavoring mezzanine area samples also showed the 

highest concentrations with a 24 sample range of 2.5 ppb to 53.3 ppb. All other area samples 

in the facility were below 6.0 ppb for 2,3-hexanedione.

Tables A5 and A6 compare the diacetyl and 2,3-pentanedione concentrations for area 

samples collected in the same location during the first (November 2012) and second (April 

2017) industrial hygiene surveys. Area sample concentrations of diacetyl (Table A5) were 

higher in the finished goods warehouse, flavoring room, flavoring room mezzanine, and 

greens warehouse in April 2017. Diacetyl concentrations were lower in the maintenance 

shop, nonproduction offices (both downstairs and upstairs), packaging mezzanine, quality 

control room, reception area, and roasting mezzanine. Area sample concentrations of 

2,3-pentanedione (Table A6) were higher in the finished goods warehouse, flavoring room, 

flavoring room mezzanine, greens warehouse, quality control room, roasting, and the roasting 

mezzanine April 2017.
Page 26 Health Hazard Evaluation Report 2012-0170-3372

Full-shift Evacuated Canisters

During our first industrial hygiene visit in November 2012, personal evacuated canister 

sample concentrations were highest for employees in the flavoring room with a range of 

110.5 ppb to 323.6 ppb for diacetyl, and 56.0 ppb to 310.0 ppb for 2,3-pentanedione (Table 

A7). Concentrations in packaging ranged from 67.1 ppb to 142.1 ppb for diacetyl and 16.0 

ppb to 96.0 ppb for 2,3-pentanedione. A single sample from a production office employee 

measured 86.8 ppb diacetyl and 54.0 ppb 2,3-pentanedione. Employees who worked all over 

the plant were exposed to concentrations ranging from 67.1 ppb to 86.8 ppb diacetyl and 

42.0 ppb to 56.0 ppb 2,3-pentanedione, followed by quality control room employees (8.7 ppb 

– 30.8 ppb diacetyl, <3.2 ppb – 20.0 ppb 2,3-pentanedione), and roasting workers (7.9 ppb – 

20.5 ppb diacetyl, <3.8 ppb – 11.0 ppb 2,3-pentanedione).

Area evacuated canister sample concentrations for diacetyl and 2,3-pentanedione 

were highest in the flavoring (126.3 ppb – 323.6 ppb diacetyl, 69.0 ppb – 240.0 ppb 

2,3-pentanedione) and packaging (86.8 ppb – 292.0 ppb diacetyl, 17.0 ppb – 220.0 ppb 

2,3-pentanedione). Two samples in the production area offices gave 41.8 ppb and 69.5 

ppb diacetyl, and 25.0 ppb and 44.0 ppb 2,3-pentanedione. Results from samples collected 

outside flavoring room exhaust were 13.4 ppb and 25.3 ppb diacetyl and 15.0 ppb and 76.0 

ppb 2,3-pentanedione. 

No full-shift evacuated canister samples were taken as part of the second industrial hygiene 

survey in April 2017.

Area/Personal Inhalable Dust Samples

We collected 25 personal and 106 area samples for inhalable dust (Table A8) during our 

November 2012 industrial hygiene survey. Of the 106 area samples collected, 67 (63%) 

were below the LOD. The maximum concentration measured inside the facility was 1.2 mg/

m3 in the roasting room. Samples collected in all other areas ranged from below the LOD 

to 0.7 mg/m3. One area sample collected outside the loading dock showed an inhalable dust 

concentration of 232.5 mg/m3 on a day where many delivery trucks entered and exited the 

plant.

Of the 25 personal inhalable dust samples collected, only four (16%) were below the LOD. 

The maximum personal inhalable dust concentrations on two employees unloading green 

beans from a delivery truck were 14.9 mg/m3 and 14.8 mg/m3, measured on the same day. All 

other personal inhalable dust results ranged from below LOD to 2.7 mg/m3. 

No inhalable dust samples were collected during the second industrial hygiene visit in April 

2017.

Task-based Air Sampling Results

Evacuated Canisters

We collected three 15-minute task-based canister samples, one each in roasting, packaging, 

and the quality control room, during our first industrial hygiene visit in November 2012. The 

packaging sample results showed 249 ppb diacetyl and 175 ppb 2,3-pentanedione during 
Health Hazard Evaluation Report 2012-0170-3372 Page 27

grinding of unflavored roasted coffee beans. Concentrations in the roasting sample were 16 

ppb diacetyl and 8 ppb 2,3-pentanedione while green coffee beans were roasted and cooled. 

The quality control room followed with sample concentrations of 11 ppb diacetyl and 6 ppb 

2,3-pentanedione while sample roasting and grinding were performed.

We collected two instantaneous canister samples with a sample duration of approximately 

30 seconds. One sample by the grinder in the quality control room during grinding of 

unflavored coffee beans showed 87 ppb diacetyl and 78 ppb 2,3-pentanedione. The second 

sample, collected in the break room while a quality control technician emptied a packet of 

French vanilla flavored coffee onto a filter on a scale, showed 50 ppb diacetyl and 64 ppb 

2,3-pentanedione. These instantaneous results should not be compared to the 15-minute 

STELs.

No task-based evacuated canister samples were taken as part of the second industrial hygiene 

survey in April 2017.

Source Air Sampling Results

Modified Occupational Safety and Health Administration (OSHA) Methods

During the November 2012 industrial hygiene survey, a 15-minute source air sample 

collected at the open hatch of a hopper on the packaging mezzanine containing ground coffee 

had concentrations of 14,300 ppb diacetyl and 13,800 ppb 2,3-pentanedione. A 15-minute 

sample at the open hatch of an adjacent empty hopper on the packaging mezzanine had 628 

ppb diacetyl and 475 ppb 2,3-pentanedione. Source air samples were not collected as part of 

the April 2017 industrial hygiene visit. 

Background Pre- and Post-Shift Diacetyl and 2,3-Pentanedione Canister Results

No background pre- and post-shift evacuated canister samples were taken during the first 

industrial hygiene visit in November 2012. Table A9 presents the instantaneous evacuated 

canister pre- and post-shift background air sampling results from our second industrial 

hygiene visit (April 2017) collected in various locations throughout the facility. Diacetyl and 

2,3-pentanedione air concentrations either decreased or remained constant over the course of 

the work day for the three days sampled. Pre and post-shift concentrations were highest in 

flavoring and packaging, followed by the warehouses, roasting, and quality control room. 

Bulk Samples and Headspace Results

Results from the analyses of the bulk flavoring samples collected during the second industrial 

hygiene survey are provided in Table A10. Diacetyl was identified in seven of nine bulk 

flavoring samples, and 2,3-pentanedione was identified in almost all the flavorings in higher 

concentrations than diacetyl. 2,3-Hexanedione was measured in only one sample.

Real-time Monitoring: Total Volatile Organic Compounds (TVOCs), Dust, Carbon Monoxide 

(CO) and Carbon Dioxide (CO2)

TVOC concentrations

During the first industrial hygiene survey, the lowest TVOC concentrations were found 

in the nonproduction offices and warehouses (Table A11). The next lowest concentrations 
Page 28 Health Hazard Evaluation Report 2012-0170-3372

were found in roasting with most peaks below 1,000 ppb. There were a few peaks above 

1,000 ppb associated with cleaning tasks. The quality control room showed slightly higher 

concentrations with peaks over 4,000 ppb during roasting and grinding of coffee. The 

breakroom showed higher overall TVOC concentrations with a peak over 10,000 ppb during 

the weighing of flavored coffee. Background TVOC concentrations near the grinders in 

packaging were between 1,000 ppb and 2,000 ppb with some peaks over 50,000 ppb and 

multiple peaks over 10,000 ppb on the mezzanine over the line 7 packaging machine. The 

flavoring room showed the highest background TVOC concentrations with consistent 

readings over 2,000 ppb and peaks over 9,000 ppb on the mezzanine above the hoppers. 

The flavoring room had its own exhaust ventilation to the outside of the building. Measured 

TVOC concentrations outside the flavoring room exhaust ranged from 4,000 ppb to 10,000 

ppb and were reflective of the concentration profiles of the flavoring room area.

Table A12 shows TVOC measurements taken throughout the facility during our second 

industrial hygiene visit in April 2017. Overall, TVOC concentrations were highest in 

flavoring. The highest mean TVOC concentration was found inside the flavoring room 

grinder enclosure on line 4 (17,737 ppb) with peak reading of 342,500 ppb. The second 

highest mean TVOC concentration of 12,488 ppb was measured at the small batch barrel 

flavoring station, however that location showed the highest peak value observed at 165,900 

ppb. Outside of flavoring, packaging showed the next highest mean and peak concentrations. 

The maximum TVOC concentration in packaging was inside the enclosed mezzanine (28,556 

ppb). TVOC mean concentrations were lowest in the production manager’s office and in 

roasting. 

Dust

Table A13 shows real-time total dust measurements taken throughout the facility during our 

first industrial hygiene visit in November 2012. The highest average concentrations were 

measured in roasting and ranged from 0.16 to 1.59 milligrams per cubic meter (mg/m3). 

Peak dust concentrations in roasting were observed up to 9.36 mg/m3. The greens warehouse 

showed the second highest concentrations of total dust which was due to unloading of the 

green coffee bean bags from the box truck; some peak concentrations were as high as 3.77 

mg/m3. The QC room showed peaks of up to 2.05 mg/m3 during the roasting and grinding of 

coffee, but overall the concentrations were low. Packaging and flavoring both showed low 

concentrations of total dust ranging from 0.04 mg/m3 to 0.15 mg/m3.

No real-time dust sampling measurements were taken during the second industrial hygiene 

visit in April 2017. 

Carbon Monoxide and Carbon Dioxide 

No CO or CO2 real-time measurements were taken during the first industrial hygiene visit in 

November 2012.

Table A14 shows real-time CO and CO2 measurements collected in April 2017. In flavoring, 

average CO concentrations ranged from 1.1 ppm at the small batch barrel flavoring station to 
Health Hazard Evaluation Report 2012-0170-3372 Page 29

59.6 ppm inside the flavoring room grinder enclosure. The highest peak measurement of CO 

was observed in the flavoring room grinder enclosure (≥500 ppm, the highest concentration 

measured by the instrument), followed by the packaging area grinder enclosure (148.2 ppm). 

Average CO2 concentrations ranged from 431.2 ppm at roaster 1 operator’s desk to 1,183 

ppm inside the flavoring room grinder enclosure. The highest peak measurement of CO2 was 

observed in the flavoring room grinder enclosure (4,636 ppm); all other observed values were 

below 1,819 ppm (flavoring room ribbon elevator). 

Ventilation Assessments

During our initial walkthrough in July/August 2012, flavoring had two local exhaust 

ventilation systems, each with an exhaust fan on the outside wall. On one system, a local 

exhaust ventilation canopy hood was located approximately 24 inches above the station 

where flavoring was pumped out of a large barrel into smaller one-gallon jugs. The onegallon containers were stored in negative pressure ventilated cabinets above and below 

the bench used for weighing flavorings. Local exhaust ventilation ducts in the cabinets 

maintained the negative pressure. An open-ended ventilation duct was located approximately 

18 inches from the scale used to weigh out the liquid flavorings, and the barrel flavoring 

station had a capture hood located just below the rolling barrels. The other local exhaust 

ventilation system served the hazelnut coffee mixing station scale and rotating barrels in a 

similar configuration. Two additional fans in the wall exhausted air directly from the room. 

Cool air was provided to the room through two air-conditioning units: one that recirculated 

the room air and the other that introduced fresh air from outside. We were told that the 

flavoring room was designed to be at negative pressure to the rest of the plant via the 

ventilation system to prevent the flavorings from contaminating unflavored coffee.

Local exhaust ventilation was not present for any equipment in packaging. Roasting had 

two wall fans that exhausted plant air over the roof of the warehouses, and air from the 

roasters was directly exhausted through an afterburner system and then out of stacks on the 

roof above. Four make-up air units along the roasting room and adjacent maintenance shop 

outside wall provided supplemental makeup air. The production offices had air-conditioning 

units that fully recirculated air from the production space, while the non-production offices 

had a dedicated heating, ventilating, and air-conditioning system.

Prior to the first industrial hygiene visit in November 2012, the grinders in packaging had 

been enclosed in sheet metal shrouds (or hoods), with access doors and plastic viewing 

windows, that were vented via ductwork from the tops of the hoods to an exhaust fan located 

adjacent to the roasting room wall fans. At the small batch mixing station in flavoring, the 

open-ended ventilation duct had been moved closer to the flavoring scale, and the capture 

hood beneath the rotating barrels had been relocated above the barrels. The other local 

exhaust ventilation system in flavoring had been modified to meet the requirements of the 

newly-renovated hazelnut coffee process line. The system included a grinder ventilation hood 

enclosure similar to those in packaging, ductwork to the new enclosed ventilated automated 

mixer, and a canopy hood above its flavoring carboy.

Table A15 presents the individual measurements obtained from the ventilation system in 

the plant in November 2012. They were collected with an airflow hood or a rotating vane 
Page 30 Health Hazard Evaluation Report 2012-0170-3372

anemometer and represent a snapshot of the overall production area ventilation profile at 

the time of the sampling. No holes were drilled in the ductwork and pitot-tubes were not 

used as would be done in a full ventilation assessment. Any changes in ventilation system 

operation or performance, production operations, doors opening or closing, or pressure 

differentials between adjacent spaces could significantly affect results. Also, we were unable 

to measure airflow through the afterburners in the roasting room or determine the sources of 

the combustion air. We made no attempt to control the use of afterburners as we collected our 

ventilation measurements, but instead allowed the afterburners to operate as normal. Thus, 

we do not understand how afterburner operation and performance may have affected the 

results presented in Table A15. 

The most significant modification made to the facility between our first and second industrial 

hygiene visits was the enclosure of the entire mezzanine level above the packaging lines; 

it was now separate from the other production spaces. Two new supply air ducts within the 

mezzanine enclosure were added along the south wall; each duct had two openings, one high 

and one low. Two exhaust fans from the space were located in the roof near the northern end 

of the space.

Both the mezzanine supply air and exhaust fans were controlled by separate variable 

frequency drive (VFD) motors. These drives vary the fan speed by varying the frequency of 

the motor. The maximum fan speed and air flow would be achieved at a reading 60 Hertz 

(Hz), and the fan speed and air flow would both be zero at a reading of 0 Hz. During our 

visit, the supply and exhaust fans were both originally set to 42 Hz. At that setting, the supply 

air flow was estimated to be 8,900 cfm. Ventilation smoke released at openings in the floor 

showed that the mezzanine space was neutral to packaging. Working with the maintenance 

manager, different VFD settings were tested according to Table A16. In the end, the VFDs 

were set to 30 Hz for the supply fans and 60 Hz for the exhaust fans late morning on April 

13, 2017 to properly maintain the mezzanine under negative pressure compared to the 

grinding/packaging space. 

Gaps observed in the enclosure around the grinder feeding lines 7 and 8 during the November 

2012 industrial hygiene visit were sealed with spray foam before our April 2017 visit, and a 

differential pressure gauge was added to help monitor the enclosure performance. However, 

there was still no skirting around the bottom of the enclosure. The exhaust flow from this 

enclosed grinder was now the only exhaust point served by the connected exhaust fan; 

previously the fan also served the grinder enclosure for the old grinder on lines 5 and 6, but 

that opening had been capped. The 12-inch exhaust duct opening leading from the top of 

the grinder enclosure was equipped with a damper to help regulate flow. The damper was 

roughly 50% open during our visit, and the exhaust flow from the enclosure was estimated to 

be 400 cubic feet per minute (cfm). Ventilation smoke released at the base of the enclosure 

showed that the enclosure was neutral to only weakly negative, depending on where the 

smoke was released (closer to the exhaust end was more likely to be negative).

The layout of the flavoring room and the associated LEV systems were fundamentally the 

same during both industrial hygiene surveys. The exhaust system was comprised of two 

exhaust fans/circuits. One fan (Exhaust Fan 1) served eight local exhaust hoods, which 
Health Hazard Evaluation Report 2012-0170-3372 Page 31

included the barrel mixing station, the flavor mixing duct hood, the flavor storage cabinets, 

a general exhaust grille behind the flavoring storage rack and a flavor pump station hood. 

There were also three exhaust grilles in the duct behind the flavoring barrel storage rack. 

This LEV system was designed as a common negative pressure plenum with takeoffs from 

the main plenum to each hood. The four exhaust intakes associated with the barrel mixing 

station had individual dampers to help control the air flow, while the four intakes further 

downstream did not have dampers. The result of this design was that hoods closest to the 

fan (i.e., those associated with the barrel mixing station) generally had higher flow rates 

than those downstream. The exhaust hood over the flavor pumping station did not have any 

measurable exhaust flow. Furthermore, the exhaust duct downstream of the flavor bench and 

storage cabinets was in poor condition with the tape on the duct seams peeling off. 

The second exhaust fan (Exhaust Fan 2) served the flavoring pump station for the ribbon 

blender, the ribbon blender hood, and the grinder enclosure. There was no measurable 

exhaust in the canopy hood over the flavorings carboy, but it may not have been necessary 

since it appeared to be sealed and was pumped to a closed ribbon blender. Estimated flow 

rates for the exhaust hoods are shown in Table A17, along with the values measured in 

November 2012, for comparison.

In April 2017, gaps in the enclosure for the flavoring room grinder, observed in November 

2012, were sealed with spray foam and a differential pressure gauge was installed in the duct 

leading from the enclosure, but there was still no skirting around the bottom of the enclosure. 

The damper in the exhaust duct for the grinder enclosure was almost completely closed. 

Qualitative tests with ventilation smoke tubes showed that the grinder enclosure was neutral 

to only weakly negative.

The quality control room appeared the same during both industrial hygiene visits. Smoke 

testing on the large range hood located over the sample roasters showed good capture on that 

side of the hood, while there was poor capture on the side of the hood over the stove burners. 

All air supply in production offices was recirculated from the production area. There were 

two ceiling level air returns, one located in the locker room and one in the maintenance 

manager’s office. Most production offices and break room doors were open throughout the 

day shift during both industrial hygiene visits. However, the doors between the locker room 

and quality control room were kept closed (to the production area) during the day.

Informal Employee Interviews during Walkthrough Visit 

Twenty-two of 26 onsite employees were interviewed individually. Some employees noted 

symptoms that they attributed to work: occasional sneezing due to odors, sinus problems 

due to green coffee dust, and skin issues due to cardboard or roasted coffee beans. Diagnoses 

reported among interviewed employees included seasonal allergies, asthma, and COPD. 

Approximately half noted they were current or past smokers. Some employees in production 

noted that once they completed the tasks for their primary job title, they often helped with 

other production tasks, or sometimes, they would fill-in if someone was absent for the day. 

On any given day, some supervisors also helped, as needed, with production tasks (e.g., 

roasting, grinding, weighing, or packaging). Some office employees started at the company in 
Page 32 Health Hazard Evaluation Report 2012-0170-3372

coffee processing jobs before moving to office positions. Some employees reported working 

at another coffee roasting and packaging facility before working at this facility. Multiple 

employees noted that hearing protection was available for voluntarily use when roasting. 

Medical Survey Results (September 2012) 

NIOSH Medical Survey 

Of approximately 85 current employees at the coffee roasting facility during our medical 

survey, 75 (88%) participated in one or more components of the medical survey (Table A18). 

The majority of employees were male (68%) and Hispanic (69%), with an average age of 35 

years (median age 34, range 18-67 years). 

The average duration of employment at the current facility was 2.9 years; the median 

duration was 1.3 years, and the range was 0.04-9.3 years. Among the participants, 31 (41%) 

worked at the current facility one year or less; 28 (38%) worked at the facility between one 

and five years, and 16 (21%) worked there five or more years. Of the 75 employees, 12 had 

also worked at the old facility before the new facility opened in 2003. Mean years employed 

at the current and old facility was 4.3 years and range from months to 25.0 years (Table A18).

At the time of the survey, 67% of the 75 participants reported currently working in or 

spending time in the grinding/packaging room (n = 50) or the flavoring room (n = 50) (Table 

A19). The number currently spending time in either area was 63 (84%). The number working 

or spending time in both areas was 37 (49%). During their tenure at the current facility, 58 

(77%) participants had ever worked or spent time in the grinding/packaging room, and 54 

(72%) had ever worked or spent time in the flavoring room, with 66 (88%) having ever spent 

time in one or the other high alpha-diketone exposure areas. 

Symptoms and Diagnoses

At the time of the survey, 36 (48%) participants reported one or more lower respiratory 

symptoms in the past 12 months: regular trouble breathing, woken by shortness of breath, 

woken with chest tightness, usual cough, wheeze or whistling in chest, asthma attack, or 

troubled by shortness of breath when hurrying on level ground or walking up a slight hill. 

Of the 75 participants, 21 (28%) reported shortness of breath hurrying on level ground or 

walking up a slight hill (Table A20). Of these 21 participants, nine reported being short of 

breath walking with people of his or her own age on level ground, and five reported having 

to stop for breath after walking about 100 yards or after a few minutes on level ground. Nine 

persons did not provide the start date or give enough information on the start date, precluding 

a determination of whether they had pre-existing shortness of breath before employment. Six 

persons reported their shortness of breath started before their hire date, and five reported their 

shortness of breath started after their hire date at the plant, while one reported shortness of 

breath onset started within one month of hire.

The prevalences of other symptoms over the last year and last four weeks are listed in Table 

A20. Some participants with mucous membrane irritation of eyes, nose, or sinuses attributed 

it to green coffee or roasted coffee dust, smoke, pallet dust/debris, heat in the roasting room, 
Health Hazard Evaluation Report 2012-0170-3372 Page 33

or the burlap bags. Three participants noted that coffee dust caused or aggravated their 

asthma type symptoms (e.g., cough, wheeze, awakening with chest tightness or shortness 

of breath). At the time of the survey, 26% (20/75) of participants reported one or more of 

the following asthma-type symptoms in the past 12 months: wheezing or whistling in their 

chest, waking up with chest tightness, or awakening by an attack of shortness of breath. Of 

the 20, one reported current asthma, and one reported a past physician diagnosis of asthma. 

Prevalences of self-reported physician diagnoses are reported in Table A21. No current 

worker participants reported a diagnosis of emphysema, bronchiolitis obliterans, interstitial 

lung disease, hypersensitivity pneumonitis, or chemical pneumonitis. No current employee 

participants reported having changed job duties because of breathing difficulties. 

Thirty-three (44%) participants reported ever wearing a disposable respirator at the plant. 

(Participants were shown pictures of disposable dust respirators when asked if they had 

ever worn a disposable respirator at the facility.) Table A22 summarizes tasks participants 

performed while wearing the disposable respirators. Four participants reported wearing 

half-face respirators in the flavoring room. Sixteen (21%) participants reported ever wearing 

hearing protection at the plant. 

 

NHANES III Comparison of Symptoms and Diagnoses

In comparison to expected numbers from the NHANES III survey [CDC 1996], participants 

had a 1.6-fold significantly higher prevalence of shortness of breath on exertion in response 

to the question of shortness of breath on level ground or walking up a slight hill [SMR 1.6 

(95% CI:1.0-2.4] (Table A23). This degree of shortness of breath is less than those degrees 

used in our index of suspicion for obliterative bronchiolitis, but persons with higher degrees 

of shortness of breath respond affirmatively to this question as well. The other symptom 

that approached statistical significance was wheeze in the last 12 months, with a SMR of 

1.5 (95% CI: 0.9-2.5). No statistically significant excesses of physician-diagnosed asthma, 

chronic bronchitis, cough, phlegm, sinus problems, or eye and nasal symptoms, existed in 

comparison to the national sample. 

Medical Tests

Table A24 summarizes the lung function testing results for current workers. Of 69 

participants with spirometry results, five had obstructive abnormalities, two had 

restrictive abnormalities, and eight had low FEF25-75. Of the five workers with airways 

obstruction, four had mild obstruction, and one had moderate obstruction. We administered 

bronchodilator to three participants with mild obstruction, of whom one met the definition of 

reversibility. All five participants with obstruction had normal diffusing capacity and alveolar 

volumes. The two with a restrictive pattern on spirometry had a low DLCO or alveolar 

volume. Four other participants with low DLCO or alveolar volume had normal spirometry.

Of the 45 participants who completed the mannitol challenge test, five had abnormal tests, 

reflecting bronchial hyperactivity. Three had mildly increased sensitivity and one moderate 

sensitivity of the airways. All five had normal spirometry, diffusing capacity, and alveolar 

volume. Two of those with abnormal mannitol tests reported no respiratory symptoms, 

which is inconsistent with a diagnosis of clinical asthma. Four of the five with an abnormal 
Page 34 Health Hazard Evaluation Report 2012-0170-3372

mannitol challenge test participated in the blood draw, and three had elevated total IgE 

reflecting atopy, but none had detectable levels of specific IgE to allergens from green coffee 

beans, coffee, or castor bean. 

Of 60 current employee participants who took the ImmunoCAP blood tests, all had evidence 

of having been exposed to green coffee beans by their IgG levels (mean 1.54 milligrams 

per liter (mg/L). The great majority also had evidence of exposure to coffee (n=57, 95%, 

mean 0.95 mg/L) and castor beans (n=52, 87%, mean 0.60 mg/L). Of the 60 participants, 

22 (36.6%) had high levels of total IgE; no participants who underwent testing had specific 

IgE to coffee or green coffee beans. One participant had specific IgE to castor beans. This 

participant reported no physician diagnosed asthma, but at the time of the medical survey, 

reported waking up with chest tightness in the past 12 months but not in the previous 

four weeks. The participant’s spirometry was normal; the participant did not complete the 

mannitol challenge test. 

Lung Function Comparison to National Rates (NHANES III) 

Of the 69 participants in the NIOSH spirometry survey five had obstructive spirometric 

abnormalities (Table A25). This represented a statistically significant 2.7-fold excess (95% 

confidence interval (CI) = 1.2-6.4) in comparison to the general U.S. population sample 

studied in NHANES III, adjusted for age distribution, race, sex, and smoking history. The 

SMRs for abnormal restrictive spirometry (0.4; CI = 0.1-1.6) and FEF25-75 (1.1; CI = 0.6-

2.2) were not elevated.

Lung Function by Work Area

The statistical models that assessed spirometry outcome related to work area contained the 69 

participants who underwent spirometry. Participants who reported currently spending work 

time in both the grinding/packaging room and flavoring room had significantly lower FEV1/

FVC ratios (expressed as a percent) compared to participants who reported not currently 

spending time in either of the areas (77% vs. 83% p = 0.01). This analysis controlled for age 

and pack-years of smoking. Participants who reported currently spending work time in either 

the grinding/packaging room or the flavoring room had a marginally significantly lower mean 

FEV1/FVC ratio compared to participants who currently did not spend work time in either 

area (80% vs. 83% p = 0.08). Participants who reported currently spending time in both high 

exposure areas had significantly lower percent predicted FEF25‐75 than those who reported 

not currently spend time in both areas (83% vs. 104%, P=0.002). A logistic regression of 

abnormal FEF25‐75 indicated a marginally significant effect of currently spending time in 

both high exposure areas (OR 8.8, CI=0.98–79.7, P=0.052).

The mean FEV1/FVC ratio for ever spending time in both the grinding/packaging room and 

flavoring room compared to never in either area was marginally significantly different (78% 

vs. 82%, p = 0.1). The mean FEV1/FVC ratio for ever spending time in either the grinding/

packaging room or flavoring room compared to never in either area was not statistically 

different (80% vs. 83%, p = 0.3), but the smaller size of the comparison group (n = 9) who 

had never worked in the areas lowered the statistical power. Current or ever major work 

area alone (without including time spent in the same area) was not associated with FEV1/
Health Hazard Evaluation Report 2012-0170-3372 Page 35

FVC ratio. No other lung function parameter was associated with major work area or with 

time spent in these two high alpha-diketone exposure areas. No lung function parameter was 

associated with spending work time (either currently or ever) in the roasting room.

Symptoms by Work Area

Currently spending work time in the roasting room was significantly associated with having 

trouble with breathing in the last 12 months (OR 3.8, CI = 1.0 – 14.0, p = 0.044); wheeze 

in the last 12 months (OR 3.39, CI = 1.0 – 11.3, p = 0.047); sinus symptoms in the last 12 

months (OR 4.2, CI = 1.2 – 14.6, p = 0.025); and burning eyes in the last 12 months (OR 

4.37, CI = 1.3 – 15.2, p = 0.020). There were no significant associations between symptoms 

and currently spending work time in the flavoring and/or grinding and packaging rooms.

Possible Work-related Lung Disease

Current workers meeting index of suspicion for possible obliterative bronchiolitis

There were six participants among the current employees for whom we had the highest 

suspicion of possible obliterative bronchiolitis using the criteria described in the methods 

section. Five of the six met the shortness of breath on exertion criteria, and at some time 

during their tenure had the flavoring room or the grinding/packaging room as their major 

department assignment or spent some time in these areas. Three of the five reported post-hire 

onset of the shortness of breath, and two did not give a date of onset. Four of the six reported 

other lower respiratory symptoms. Three of the six had lung function abnormalities. Four of 

the six had never smoked, and two had a minor smoking history of less than one pack-year. 

One of the six reported a diagnosis of walking pneumonia that did not respond to antibiotics, 

and one had a post-hire diagnosis of asthma but did not report current asthma. 

Current workers meeting index of suspicion for possible work-related asthma

We had suspicion that five other employees had work-related asthma, which includes 

both occupational asthma where exposures at work cause onset of asthma and workexacerbated asthma where exposures at work exacerbate but did not cause onset of the 

asthma. In examining the medical survey results of the current employees, we noted two 

participants with highest suspicion of possible occupational asthma. One participant had a 

positive antibody test for castor beans. The second participant had mild obstruction, a posthire diagnosis of asthma, and asthma medication use. (The participant noted in the above 

section with post-hire asthma may also possibly have occupational asthma.) We noted three 

participants with highest suspicion of possible work-exacerbated asthma. All three reported 

asthma-type symptoms that improved away from work. One had pre-hire onset of symptoms. 

Two were mannitol sensitive and had elevated total IgE. 

In summary, the eleven employees for whom we had the highest suspicion of occupational 

lung disease, either obliterative bronchiolitis or work-related asthma, had abnormalities or 

symptoms that merited follow up and clinical referral.

Former Workers

We tested 13 former workers, of whom five reported physician-diagnosed obliterative 
Page 36 Health Hazard Evaluation Report 2012-0170-3372

bronchiolitis. At the time of our testing, they ranged in age from 25 to 42 years. All five 

reported post-hire onset of lower respiratory symptoms and abnormal spirometry (FEV1 range: 

22.4%−41.9% of predicted; FVC range: 73.1%−88.3% of predicted; FEV1/FVC ratio range: 

25.9%−43.6%; FEF25-75 range: 6.1%-12.3% of predicted). Two had obstructive abnormalities 

with reduction in FEV1, and three had mixed abnormalities with reduction in FEV1/FVC ratio 

and FVC. None had reversibility with bronchodilator. The two participants with the lowest 

percent predicted FEV1s (22.4% and 31.9%) had low alveolar volumes. 

All five former workers, who were diagnosed with obliterative bronchiolitis, reported working 

in the flavoring room (as a mixer, flavor specialist, hand packer/helper, packaging machine 

operator, and/or grinder); four reported working in the grinding/packaging room (as a helper, 

packaging machine operator, and/or grinder). Some reported that in addition to their primary 

job, they sometimes had secondary duties helping out in other areas including grinding coffee or 

performing re-works in the flavoring room. Two of the five had high levels of total IgE; none of 

the five had specific IgE to coffee, green coffee beans, or castor beans. Only one of five had ever 

smoked, although the age less than 40 years likely precluded smoking as an etiology for the 

severe spirometric abnormality.

Of the remaining eight former workers tested, ages ranged from 22 to 51 years. All eight 

reported chest symptoms. One had mild restriction on spirometry without bronchodilator 

response. The remainder had normal spirometry and other lung function tests. One had 

abnormal specific IgE to green coffee, coffee, and castor bean allergens as well as an elevated 

total IgE. Two others also had high total IgE. 

Company-provided Spirometry 

The company provided NIOSH with 145 pdf copies of spirometry reports from testing in 

October 2014 (for 80 employees) and October 2015 (for 65 employees). In 2014, the companycontracted reviewing physician reported 23 (29%) of 80 employees reported one or more 

respiratory symptoms (cough, wheezing, or shortness of breath on any degree of exertion) and 

the 23 had a mean FEV1 % predicted of 93% and FVC % predicted of 94%. Of the 23, 43% 

were current smokers. The smoking prevalence for all 80 employees was not noted. In 2015, the 

company-contracted reviewing physician reported 17 (26%) of 65 employees reported having 

one or more respiratory symptoms (cough, wheezing, or shortness of breath on any degree of 

exertion) with 41% being current smokers. The overall smoking prevalence of tested employees 

was reported to be 30%. The physician noted no significant differences in spirometry values 

between employees with and without respiratory symptoms. He also reported that review and 

comparison of employees with spirometry tests in 2014 and 2015 did not reveal significant or 

unusual trends.

We excluded two of the spirometry reports from 2015 because the resolution of the plots was 

not good enough for NIOSH to definitively identify the usable trials. Of the 104 employees 

with company-provided spirometry reports, 39 (37.5%) had tests in both 2014 and 2015, and 

the remaining 65 had been tested in only one of those years. Overall, we found the company’s 

spirometry testing to be of good quality with 140 having an A, B, or C quality grade for both 

FVC and FEV1. Of the 143 tests reviewed, 141 (98.6%) had an FVC quality grade of A 

(69.9%), B (20.3%), or C (8.4%), and 140 (97.9%) had a FEV1 quality grade of A (73.4%), B 
Health Hazard Evaluation Report 2012-0170-3372 Page 37

(16.8%), or C (7.7%). 

Overall, NIOSH interpretations were similar to those of the company-contracted reviewing 

physician. The reviewing physician appeared to use the same ATS interpretative strategies for 

lung function tests as NIOSH [Pellegrino et al. 2005]. We noted a few differences between 

NIOSH and the reviewing physician when it came to grading the severity level of spirometric 

restriction. This might be explained if the reviewing physician used the value of the percent 

predicted FVC rather the value of the percent predicted FEV1 to grade the severity of 

spirometric restriction. We used the FEV1 percent predicted to categorize the severity (e.g., 

mild, moderate, severe) of restrictive and obstructive abnormalities [Pellegrino et al. 2005]. 

Of the 69 employees that completed spirometry during the health hazard evaluation, 27 had 

additional tests collected during the company’s medical surveillance; the 2014 and 2015 

company-provided reports included results on 77 workers that NIOSH had not previously 

tested with spirometry.

Longitudinal Changes in Spirometry 

Of the 27 employees tested by NIOSH who also had a company-provided spirometry test 

result, one employee had a drop in FEV1 greater than 15%, after accounting for expected 

loss due to aging, between the NIOSH test and the most recent company provided test. The 

employee’s FVC declined less than 15%. This employee’s NIOSH spirometry test showed 

normal spirometry. Two years later, the company-provided spirometry test showed a mild 

abnormality. 

Of the 23 employees that did not have NIOSH spirometry testing but had two companyprovided spirometry tests, none had drops in FEV1 or FVC greater than 15%, after 

accounting for expected loss due to aging.

Discussion

Diacetyl, 2,3-pentanedione, 2,3-hexanedione, other VOCs, and other chemicals such as CO 

and CO2 are naturally produced when coffee beans are roasted, and grinding roasted coffee 

beans produces greater surface area for the off-gassing of these chemicals [Anderson et al. 

2003; Akiyama et al. 2003; Daglia et al. 2007; Newton 2002; Nishimura et al. 2003; Raffel 

and Thompson 2013]. Occupational exposure to diacetyl and 2,3-pentanedione can cause loss 

of lung function and the lung disease obliterative bronchiolitis [NIOSH 2016a]. Exposure to 

green and roasted coffee dust is a risk factor for work-related asthma [Harvey et al. 2020].

Alpha-Diketones 

Personal Air Sampling 

Evacuated canister samples collected during the walkthrough visit in July/August 2012 

were collected over three-hour periods. Direct comparison to the 8-hour NIOSH REL

is not applicable because the evacuated canister method is not validated for personal 

sampling. However, these samples provided initial important information on alpha-diketone 

concentrations in the facility and were used to develop the sampling strategies for the future 
Page 38 Health Hazard Evaluation Report 2012-0170-3372

industrial hygiene surveys. 

In November 2012, all personal air sample concentrations were above the NIOSH REL

for diacetyl except for one in the finished goods warehouse. The highest full-shift personal 

diacetyl concentration was measured on a packaging room employee sample (166 ppb). 

During the second visit in April 2017, all personal air sample concentrations were above 

the NIOSH REL for diacetyl except one sample on an employee working in the upstairs 

nonproduction offices. The highest measured personal exposure in April 2017 was 163.8 ppb 

on an employee working in the flavoring room. As noted earlier, the REL should be used as 

a guideline to indicate when steps should be taken to reduce exposures in the workplace. The 

risks associated with the measured levels are higher than NIOSH recommends. 

As described in the quantitative risk assessment from the NIOSH Criteria Document (Tables 

5-27 and 5-29) [NIOSH 2016a], after a 45-year working lifetime exposure to 100 ppb (a 

concentration lower than the highest concentration (166 ppb) measured at this facility), 

NIOSH estimated that 25.7 in 1,000 workers would develop reduced lung function (FEV1 

below the lower limit of normal). NIOSH predicted that around 2.7 in 1000 workers exposed 

to diacetyl at 100 ppb would develop more severe lung function reduction (FEV1 below 60% 

predicted, defined as at least moderately severe by the American Thoracic Society [Pellegrino 

et al. 2005]). After a 45-year working lifetime exposure to 200 ppb (a concentration higher 

than the highest concentration measured at this facility), NIOSH estimated that 58.7 in 1,000 

workers would develop reduced lung function (FEV1 below the lower limit of normal). 

NIOSH predicted that 6.4 in 1000 workers exposed to diacetyl at 200 ppb would develop 

more severe lung function reduction. The effects of a working lifetime exposure at 166 ppb 

is closer to 200 ppb than 100 ppb. NIOSH recommends keeping diacetyl concentrations 

below 5 ppb because at this level, the risk of reduced lung function after a working lifetime 

of exposure is below 1 in 1000 workers. NIOSH recommends taking steps to reduce diacetyl 

exposures to below the REL of 5 ppb whenever possible.

The highest full-shift personal sample results of 2,3-pentanedione observed during both 

visits were measured on employees working in the flavoring room with a maximum 

concentration of 199.0 ppb in 2012 and 899.6 ppb in 2017. Higher sample concentrations 

of 2,3-pentanedione than diacetyl in the flavoring room is consistent with the historical 

substitution of 2,3-pentanedione for diacetyl in the flavorings added to whole bean and 

ground coffee and was reflected in the headspace results for the nine bulk flavoring samples 

collected in April 2017. Although this substitution was intended to lower the risk of diacetylrelated lung disease, animal experiments have shown that 2,3-pentanedione is as hazardous to 

animal tissue as diacetyl [Morgan et al. 2012, 2016; Hubbs et al. 2012]. 

With the exception of samples in the flavoring room, results generally showed personal 

exposures to diacetyl and 2,3-pentanedione were higher during our first visit (November 

2012) compared to our second visit (April 2017). Alpha-diketone emissions of diacetyl and 

2,3-pentanedione into workplace air are directly related to the amount of roasted coffee being 

produced. During the second visit, the company had added additional packaging equipment 

and was roasting, flavoring, and packaging approximately 70% more coffee. Increased 
Health Hazard Evaluation Report 2012-0170-3372 Page 39

production volume would be anticipated to result in higher personal exposures. However, 

the facility had undergone renovations to its ventilation and processing systems, enclosed the 

packaging mezzanine, and improved its grinder enclosures since our first visit. These changes 

were effective at limiting the anticipated increase in alpha-diketone exposures throughout the 

facility associated with the increased production volume. Overall, the majority of personal 

sample diacetyl concentrations in 2017 were lower than those observed in 2012 (Tables 

A4 and A5). The notable exceptions were higher diacetyl and 2,3-pentanedione personal 

sample concentrations measured in the flavoring room in 2017. However, these sample 

concentrations do not take into account the required respiratory protection, which if used 

properly, significantly reduces actual employee exposures. 

Area Air Sampling

Air samples in production areas from both industrial hygiene surveys showed levels of 

diacetyl and 2,3-pentanedione over the NIOSH RELs of 5 ppb and 9.3 ppb. However, these 

results cannot be compared directly to exposure limits but could result in over-exposure to 

employees working in these areas without respiratory protection. 

In contrast to personal sample results, the area samples in production/storage areas, 

(flavoring, packaging and warehouses) showed higher results during the second visit. The 

increased volume of coffee being produced and stored during our second visit could result in 

the larger values due to more off-gassing of diacetyl and 2,3-pentanedione. 

Bulk Samples

Diacetyl and 2,3-pentanedione are known respiratory hazards; however, in some flavoring 

formulations, they might not be listed as ingredients on safety data sheets (SDSs) when they 

are present [LebBouf et al. 2019]. This might be because diacetyl or 2,3-pentanedione are 

part of a proprietary mixture deemed trade secret, or diacetyl or 2,3-pentanedione may not 

be listed on SDSs if they are present at less than 1% composition [OSHA 2012]. Diacetyl 

and 2,3-pentanedione also may be present in starter distillates which have a generally 

recognized as safe (GRAS) designation by U.S. Food and Drug Administration for ingestion 

by consumers [FDA 2008]. The GRAS designation does not take into account potential 

workplace exposures due to emissions from bulk flavorings. Diacetyl and 2,3-pentanedione 

as volatile constituents in headspace analysis have been identified in liquid flavorings; 

however, the alpha-diketones were not listed on flavorings’ SDSs [LeBouf et al. 2019].

This coffee roasting, flavoring, and packaging facility requested that its flavoring suppliers 

eliminate diacetyl from the flavorings; however, our analyses of head space samples from 

bulk samples showed that they continued to contain some diacetyl and other alpha-diketones 

(2,3-pentanedione, 2,3-hexanedione) that were being used as diacetyl substitutes. Headspace 

analysis from the July/August visit in 2012 showed that for three of the flavorings tested, 

2,3-pentanedione concentrations were one to two orders higher than diacetyl. Analyses 

of bulk flavoring samples collected during the April 2017 industrial hygiene survey 

identified 2,3-pentanedione in all nine samples and diacetyl in seven of the nine samples. 
Page 40 Health Hazard Evaluation Report 2012-0170-3372

2,3-Hexanedione was measured in only one sample. 

Dust

During our visits, we noticed that the roasting room was hot and smoky at times, and coffee 

dust was aerosolized when compressed air was used to clean. The high dust concentrations 

in these areas may have caused irritation and respiratory symptoms among some employees. 

Spending time in the roasting room was significantly associated with sinus trouble, burning 

eyes, wheezing, having trouble with breathing in the last 12 months at the time of the medical 

survey. 

The majority of dust sample results in 2012 were at or below the limit of detection, except 

in roasting and the greens warehouse. From the real-time dust sampling, we observed high 

concentrations in the greens warehouse (during the unloading of burlap bags of green coffee 

beans) and in the roasting room. 

Although area inhalable dust concentrations were below OSHA and ACGIH occupational 

exposure limits, coffee dust, even at low concentrations, is known to cause respiratory 

symptoms [Zuskin et al. 1993; Sakwari et al. 2013]. Green and roasted coffee dust and castor 

beans (from cross-contamination of bags used to transport coffee) are known risk factors for 

occupational asthma [Figley and Rawling 1950; Karr et al. 1978; Zuskin et al. 1979, 1985; 

Thomas et al. 1991]. People who become sensitized (develop an immune reaction) to coffee 

dust can subsequently react to relatively low concentrations in the air. Others may experience 

irritant-type symptoms from exposure to coffee dust [Oldenburg et al. 2009]. 

Real-time Sampling for CO, CO2, and TVOCs

Our real-time monitoring found that the highest overall levels of total CO, CO2, and TVOCs 

were observed in flavoring and packaging. 

Measurements of CO in April 2017, collected beside the new grinder for lines 5 & 6 and 

near the grinder enclosure for lines 7 & 8 in packaging and inside the flavoring room 

grinder enclosure, exceeded the NIOSH REL of 35 ppm. Only one measurement inside the 

flavoring room grinder enclosure exceeded the OSHA PEL (50 ppm). Also, peak levels of 

CO exceeded the NIOSH ceiling of 200 ppm inside the flavoring room grinder enclosure. 

The NIOSH ceiling limit should not be exceeded at any time; however, employees do 

not typically enter the grinder enclosure during operation. The highest average CO2

concentrations were observed in the flavoring room with a range of 893.4 ppm to 1,183.0 

ppm, which was below the NIOSH REL (5,000 ppm) and OSHA PEL (5,000 ppm). 

Interpreting real-time sampling results in a complex industrial setting is often difficult. 

Variations in TVOCs, CO2, or CO may be the result of nearby work tasks, tasks in adjacent 

areas of the facility, or a combination of both. Efforts were made to minimize instrument 

variability (e.g., daily calibration and maintenance), but variations occur between 

instruments. The Tiger TVOC monitors were used only in flavoring during the 2017 visit and 

were not used in 2012. All other TVOC measurements were taken with the RAE Systems, 
Health Hazard Evaluation Report 2012-0170-3372 Page 41

ppbRAE 3000 monitors. 

There is no standard for TVOC concentrations, however they can be used as a guideline tool 

for investigation of emissions and efficacy of controls. The TVOC background concentrations 

ranged from 1,000 ppb−2,000 ppb with some brief peaks over 52,000 ppb and several 

others over 10,000 ppb in the grinding/packaging room. The real-time instruments used are 

unable to distinguish between compounds in the TVOC readings. Thus, it is not possible 

to estimate the contribution of diacetyl and 2,3-pentandeione to the TVOC values, but the 

readings are useful in identifying areas and processes that release the highest concentrations 

of TVOCs. Furthermore, NIOSH sampling results for alpha-diketones have indicated their 

presence in relatively high concentrations in areas that correspond to the real-time TVOC 

results. The flavoring and grinding/packaging rooms consistently showed the highest 

background concentrations in the facility. In the grinding/packaging room, we observed 

high TVOC concentrations above the grinders and hoppers of roasted coffee. We know from 

published studies that diacetyl and 2,3-pentanedione are produced during the coffee roasting 

process [Daglia et al. 2007] and are released during grinding [Akiyama et al. 2003]. In the 

break room, we recorded TVOC concentration readings as high as 10,873 ppb while a QC 

technician weighed ground, flavored coffee. As we have recommended in previous interim 

letters, quality control checks of flavored coffee should not be performed in the break room. 

Respiratory Protection

The respirator protection requirements for employees at this facility varied over time. In 

July/August 2012, N95 filtering facepiece respirators were available but not required. In 

September 2012, flavoring specialists and mixers sometimes wore half-face air-purifying 

respirators. In November 2012, flavoring employees were required to wear full-face powered 

air-purifying respirators (with an APF of 1000). In April 2017, half-face air-purifying 

respirators were required in flavoring, the packaging mezzanine, while feeding roasted coffee 

into the new corner-seal packaging line, and during rework. 

Until engineering and administrative controls are in place, we recommend respiratory 

protection to reduce exposures to alpha-diketones. The choice of respirator should be guided 

by personal exposure sampling for diacetyl and 2,3-pentanedione. Information on respirators 

can be found in Chapter 8 of the NIOSH Criteria Document [NIOSH 2016a] and in the 

NIOSH Respirator Selection Logic [NIOSH 2004]. The selection of a specific respirator 

depends on the particular situation and should be made only by qualified personnel [NIOSH 

2016a]. 

Ventilation 

The most significant modification made to the facility following the November 2012 

industrial hygiene visit was the enclosure of the entire mezzanine level above packaging. 

During our April 2017 industrial hygiene visit, it was separate from all other production 

spaces. Two new air ducts to supply air to the enclosed mezzanine were added along the 

south wall, and each duct had two supply openings, one high and one low. Two exhaust fans 

were located in the roof near the northern end of the space. The air-handling unit serving the 
Page 42 Health Hazard Evaluation Report 2012-0170-3372

nonproduction office areas had also been replaced since 2012.

While the changes made since 2012 should have resulted in noticeable reductions in airborne 

concentrations of diacetyl and 2,3-pentanedione in some areas of the facility, demonstrating 

those reductions in 2017 was complicated by a 70% increase in total production since 2012. 

Enclosing the packaging mezzanine and ventilating it separately would be expected to have 

the most noticeable reductions in alpha-diketone concentrations in the enclosed mezzanine 

and the remainder of packaging. As shown in Table A3, the alpha-diketone concentrations 

were generally lower in the packaging mezzanine, which can be directly attributed to the 

additional ventilation added to the enclosure. The concentrations in the rest of packaging 

remained relatively stable between 2012 and 2017. Given the production volume increase, 

this indicates the mezzanine enclosure and added ventilation had the intended effect. 

In 2017, as in 2012, the production offices were served by air-handling units that pulled 

their supply air from packaging. All air supply in production offices was recirculated from 

the production area. There were two ceiling level air returns, one located in the locker room 

and one in the maintenance manager’s office. Most production offices and break room doors 

were open throughout the day shift. However, the doors between the locker room and QC 

area were kept closed to the production area during the day. In general, this ventilation 

configuration resulted in production offices having similar airborne concentrations of alphadiketones as the adjacent packaging area. 

Medical Survey 

This coffee plant had five cases of physician-diagnosed obliterative bronchiolitis among 

employees who have left employment. The question addressed by the NIOSH medical survey 

was whether these cases were a sentinel for disease or subclinical findings in current or 

other former employees that might reflect past or continuing disease risk. Several findings 

among the current workforce studied in 2012 suggested that occupational lung disease 

risk was present and required follow up: (1) A statistically significant 2.7-fold excess of 

measured spirometric obstruction and a 1.6-fold excess of shortness of breath on exertion 

existed in the coffee plant employees compared to the U.S. noninstitutionalized population 

of the same age, race/ethnic, sex, and cigarette smoking distribution. (2) Several employees 

reported a severe degree of shortness of breath, which is unusual in working populations. 

(3) Employees that spent time in both of the high alpha-diketone exposure areas (grinding/

packaging and flavoring rooms) had a statistically significant decrease in mean FEV1/FVC 

ratio in comparison to employees that had not worked in either of these areas, adjusted for 

the usual correlates of such ratios. (4) Employees that currently spent time in both of the high 

alpha‐diketone exposure areas had a mean FEF25–75% predicted that was 21 percentage 

points lower than employees without such exposure. (5) We identified six employees who 

had production area alpha-diketone exposures and reported shortness of breath or had 

abnormalities on the battery of medical tests, which were concerning and unlikely to be 

explained by cigarette smoking. In addition, we identified five current employees with 

suspect work‐related asthma, of whom two had likely occupational asthma.

The current employee participants had a 2.7-fold excess prevalence of obstructive spirometry. 
Health Hazard Evaluation Report 2012-0170-3372 Page 43

The five former employees with physician-diagnosed obliterative bronchiolitis had marked 

obstructive or mixed obstructive and restrictive spirometric abnormalities on our spirometry 

testing. We found no current employees with that degree of impairment on spirometry, 

although four had comparable degrees of severe shortness of breath with exertion. We found 

that employees assigned to or spending time in both grinding and flavoring areas with high 

exposure to diacetyl and 2,3-pentanedione had a 6.0 percentage points lower average FEV1/

FVC ratio, compared to employees working in neither area. This finding suggested there may 

have been a subclinical effect on spirometry in this group, which accounted for nearly half of 

the plant population. Our finding of a 21 percentage point difference in the mean FEF25–75% 

predicted in the high exposure group compared to all other employees is consistent with a 

small airways effect in employees who spent time in both high exposure areas (grinding/

packaging and flavoring rooms), as was striking in the sentinel former worker obliterative 

bronchiolitis cases whose FEF25–75 measurements were all less than 12.4% predicted. 

One purpose of spirometric measurement was to identify employees with mild or moderate 

impairment so they could be prevented from developing severe impairment like the former 

employees who were diagnosed with obliterative bronchiolitis, which precluded their 

continued employment and many activities of daily living. Of the seven current employees 

that had spirometric abnormalities during the NIOSH testing, five with obstruction and two 

with restrictive pattern on spirometry, four either reported no industrial exposures to alphadiketones, were of an age that smoking habit might explain their abnormality (although 

smokers are not precluded from developing obliterative bronchiolitis), or their symptoms 

started pre-hire and did not appear to be work-exacerbated. The remaining three, two with 

obstruction and one with restrictive pattern on spirometry, reported working or spending time 

in high exposure areas, had no smoking history, and either reported work-related symptoms, 

or there was no clear-cut explanation for their symptoms. We included employees with 

restrictive abnormalities as needing further diagnostic evaluation because the pathologic 

presence of obliterative bronchiolitis can be accompanied by restrictive spirometric 

abnormalities or even normal spirometry. This has been shown in case series of obliterative 

bronchiolitis found on surgical biopsy but accompanied with either normal or abnormal 

spirometry [Ghanei et al. 2008, Markopoulou et al. 2002, King et al. 2011]. For that reason, 

we place emphasis on a cardinal symptom of pathologic obliterative bronchiolitis, shortness 

of breath.

The 1.6-fold excess of exertional shortness of breath compared to the U.S. population was 

concerning, given that persons can have this hallmark symptom of obliterative bronchiolitis 

but have normal spirometry [Ghanei et al. 2008; King et al. 2011]. The rapid progression 

of obliterative bronchiolitis within months in some worker populations [Kreiss et al. 

2002; NIOSH 2008; Kanwal et al. 2011], and the prevalence of abnormalities in this plant 

with short median tenure of work supported institution of medical surveillance, as we 

advised in December 2012. Comparison of spirometry over time can allow identification 

of excessive decline in spirometry, if it exists, even within the normal range of spirometry. 

Early identification of such employees allows prevention of occupational lung disease 

such as obliterative bronchiolitis and asthma by counseling regarding risks, implementing 

engineering interventions to lower exposure, possibly reassigning employees to lower 
Page 44 Health Hazard Evaluation Report 2012-0170-3372

exposure jobs, and motivating employees to achieve better adherence to respiratory 

protection.

Twenty participants in the medical survey had asthma-like symptoms (wheezing or whistling 

in their chest, waking up with chest tightness, or awakening by an attack of shortness of 

breath), but only five reported a physician diagnosis of asthma. Asthma-like symptoms have 

been reported among persons diagnosed with obliterative bronchiolitis [Akpinar-Elci 2004; 

Modi et al. 2008; Cavalcanti et al. 2012]; however, respiratory health concerns are not limited 

to obliterative bronchiolitis or the use of flavorings [Harvey et al. 2020]. The coffee industry 

has a known risk of occupational asthma in relation to green and roasted coffee dusts and 

castor bean dusts from contaminated shipping bags [Figley and Rawling 1950; Thomas et al. 

1991]. Plant management reported that only new burlap bags were used; however, a majority 

of employees had IgG evidence of past exposure to castor bean allergen. It is possible the 

burlap bags became contaminated with castor bean dust in shipping containers or somewhere 

else during the transport of the green coffee beans to the coffee roasting, flavoring, and 

grinding facility. We found one employee with a history of asthma symptoms and specific 

allergy to castor bean dust, consistent with having occupational asthma which may be active 

when castor bean allergens are present in the facility. One former employee had specific 

allergy to green coffee, coffee, and castor bean, and may have occupational asthma based on 

his reported symptoms during and after employment. 

Mucous membrane symptoms, specifically eye, nose, and sinus symptoms, were commonly 

reported symptoms. Some participants with eyes, nose, or sinuses irritation attributed it to the 

burlap bags, green or roasted coffee dust, smoke, pallet dust/debris, or roasting room heat. 

Upper respiratory disease such as allergic rhinitis (hay fever, nasal allergies) and sinusitis are 

sometimes associated with lower respiratory symptoms and asthma and might precede the 

diagnosis of asthma [Shaaban et al. 2008; EAACI Task Force on Occupational Rhinitis et 

al. 2008; Rondón et al. 2012, 2017; Sahay et al. 2016]. Upper respiratory involvement (e.g., 

rhinitis, sinusitis) can result in suboptimal control of asthma. Green coffee dust is thought 

to be a more potent allergen than roasted coffee dust because roasting destroys some of the 

allergenic activity [Lehrer et al. 1978]. As discussed in the recommendations section, one 

way to prevent symptoms related to green coffee dust is to continue to make N-95 disposable 

filtering-face piece respirators available for voluntary use when emptying burlap bags of 

green coffee beans into storage silos or containers or when emptying the chaff containers or 

cleaning the green bean storage area.

In October 2014, the company instituted a medical surveillance program in response to 

our evaluation as a means of early identification of employees who might be developing 

lung disease (e.g., asthma, obliterative bronchiolitis) and to help prioritize interventions to 

prevent occupational lung disease. We reviewed company-provided spirometry conducted 

in October 2014 and October 2015. Most (98%) tests were graded A, B, or C and could 

therefore be interpreted with confidence. One employee had at least a 15% decline in FEV1 

or FVC between spirometry conducted during the NIOSH medical survey and subsequent 

contracted medical surveillance program spirometry. FEV1 and FVC are expected to decline 

by approximately 30 mL each year in the average non-smoking adult [OSHA 2013]. A 
Health Hazard Evaluation Report 2012-0170-3372 Page 45

15% decline in FEV1 or FVC, after accounting for expected loss due to aging, is more than 

expected [Pellegrino et al. 2005; Townsend MC and Occupational and Environmental Lung 

Disorders Committee 2011]. Excessive decline in FEV1 or FVC could be due to work-related 

lung disease, or other factors such as the spirometry equipment, test subject or technician 

technique, or non-work-related illness affecting results. It is important to monitor the 

change in lung function and symptoms over time in employees participating in the medical 

surveillance program, and for the employee’s healthcare provider to investigate progressive 

symptoms or excessive decline in FEV1 or FVC to address the possibility of work-related 

lung disease and rule out work-related lung disease or remove that employee from exposure 

to potential respiratory hazards at work. The systematic analysis of aggregate medical tests 

and symptoms over time help prioritize interventions to prevent work-related lung diseases in 

employees.

This health hazard evaluation had several limitations. The first is the workforce was small, 

and there was not an optimal internal control group with which we could compare the alphadiketone exposed workers. Only nine participants with spirometric measurements had never 

had any exposures in either the grinding/packaging room or the flavoring room. We had 

initially thought that we could compare flavoring employees with other production workers. 

However, the environmental data collected by NIOSH showed that the sum of diacetyl and 

2,3-pentanedione exposures were similar for employees in the flavoring room and employees 

in the grinding and packaging area of unflavored coffee. The human body cannot differentiate 

between chemicals that are created by roasting unflavored coffee and released by grinding 

and the same chemicals that are present in chemical flavors added to coffee. Both diacetyl 

and 2,3-pentanedione have comparable toxicity to the airway epithelium in animals exposed 

to the chemicals [Morgan et al. 2012; Hubbs et al. 2012]. Apart from the adverse effect of 

working in the two high apha-diketone exposure areas on FEV1/FVC ratio and percent 

predicted FEF25-75, our inability to show other exposure-response relationships for alphadiketone exposure associated with adverse respiratory outcomes is likely explained by 

most employees (including those in production offices adjacent to the grinding/packaging 

room) having similar exposures at some time during their work weeks. With little range in 

exposures, it was possible that nearly the entire workforce had exposures sufficient to have 

affected them to some degree. For that reason, we had to rely on comparisons of shortness 

of breath and obstructive abnormalities to national data. These comparisons showed that the 

workforce as a whole had excess abnormalities in obstruction and shortness of breath.

A second limitation was that our environmental measurements in November 2012 were 

unlikely to reflect diacetyl and 2,3-pentanedione levels that existed in the past when the 

five sentinel cases became ill enough to seek medical attention. One change that may have 

affected chemical exposures in the flavoring room was the substitution of diacetyl-containing 

flavorings with flavorings containing 2,3-pentanedione. However, since 2,3-pentanedione is 

not safer than diacetyl, this change was unlikely to have lowered risk to employees. Another 

change that may have lowered average levels of exposure to flavoring chemicals was the 

engineering controls introduced in the flavoring room, including exhaust hoods, ventilated 

storage cabinets, and changes in the process of flavoring coffee. Respiratory protection 

for volatile chemicals was not introduced until after our initial visit and increased in the 
Page 46 Health Hazard Evaluation Report 2012-0170-3372

flavoring room after the NIOSH medical survey. Even PAPRs with an APF of 1000 might 

have been inadequate to lower the peak exposure risk of many thousands of ppb diacetyl 

or 2,3-pentanedione for a few seconds that were measured on the mezzanine over bins of 

unflavored ground coffee stored for off-gassing. Peak exposures appeared to be risk factors 

for obstructive spirometry in the microwave popcorn industry [Kreiss et al. 2002; Kanwal 

et al 2006]. Enclosing the entire mezzanine level of packaging was the most significant 

modification made to the facility since November 2012.

A third limitation was our inability to distinguish between relative risk in flavored coffee 

production and unflavored coffee production. All five sentinel cases of obliterative 

bronchiolitis had worked in the flavoring room and were attributed to flavoring chemicals. 

However, a majority of employees in the facility had spent time in the flavoring room, with 

only 21 of 75 NIOSH medical survey participants reported not working in the flavoring room 

or entering the flavoring room as part of their job. 

A fourth limitation is that some participants did not complete all components of the voluntary 

medical survey. For example, two participants with an obstructive pattern on spirometry did 

not perform the bronchodilator test; thus, we do not know if the obstruction was reversible 

or not. Some participants with normal spirometry who reported lower respiratory symptoms 

did not perform or complete the mannitol challenge test to evaluate for asthma, and a few 

participants with lower respiratory symptoms did not perform any of the breathing tests. 

Additionally, some participants who entered high alpha-diketone exposure areas (e.g., 

maintenance staff and production supervisors) did not participate in the medical survey. 

A fifth limitation was the insensitivity of our medical testing methods for obliterative 

bronchiolitis. Although the mainstay of medical surveillance recommendations is serial 

spirometry to identify abnormal declines within the normal range, we now recognize that 

many patients with exposure-related obliterative bronchiolitis on biopsy have normal 

spirometry and normal high-resolution computed tomography scanning of the chest. The 

symptom of exertional shortness of breath is what triggered medical evaluation in those 

subsequently found to have histological changes on lung biopsy. However, few pulmonary 

physicians would consider advising lung biopsy for patients with normal spirometry and 

radiology studies. Employees should be educated to understand the limitations of the medical 

tests and to consider the risks of further exposure if they develop shortness of breath that is 

progressive and severe in degree.

A final limitation is the healthy worker effect. Workers who become ill from occupational 

lung disease leave the workforce or the area in which they become ill if they cannot perform 

the required exertion. The five former employees with obliterative bronchiolitis reflect this 

healthy worker effect. Their former colleagues continued to work and thus appear healthier 

than the entire workforce that has been exposed to alpha-diketones, some of whom have 

left due to illness. Of the other eight former employees that we tested, at least two more had 

abnormalities that may have been related to occupational lung disease. Thus, the healthy 

worker effect in current workers usually results in an underestimation of work-related 

disease. As in other workforces with former employee sentinel cases, current employees 
Health Hazard Evaluation Report 2012-0170-3372 Page 47

usually have a burden of subclinical disease [Kreiss et al. 2002, Kim et al. 2010, Kreiss et 

al. 2012]. Our findings of abnormal prevalence of shortness of breath, severity of shortness 

of breath, and excess spirometric obstruction were consistent with an additional burden of 

occupational lung disease in current workers, despite the healthy worker effect. 

In spite of the limitations, our evaluation has strengths. These include a high participation rate 

among employees, which lessens bias from testing participants who may not be representative 

of the entire current workforce. We had high quality spirometry measurements and offered 

confidentiality of results so that employees did not fear that their participation would threaten 

their employment. Additionally, we had an extensive characterization of average exposures 

by job and area. A medical surveillance program with serial spirometry and questionnaires 

can ascertain whether there is any indication of excessive declines that might predict which 

employees may be developing impairment. Serial environmental measurements can help 

evaluate whether exposures are lower with the interventions the company has made. 

Conclusions 

During both industrial hygiene visits, we identified specific work areas where personal fullshift and task-based exposures to diacetyl and 2,3-pentanedione exceeded their respective 

NIOSH REL and STEL. Additional efforts to reduce concentrations need to be made such as 

the installation of local exhaust ventilation or the introduction of more outdoor air. The changes 

made to the facility prior to our second visit in 2017 did not reduce personal exposures below 

the RELs. However, those changes did reduce general area air concentration levels below those 

observed during the first visit, despite the increased production volume. Work areas where 

grinding, packaging, or flavoring of roasted coffee beans occurred were associated with the 

highest observed personal sample diacetyl levels. Most full-shift area air sample concentrations 

of diacetyl were higher during our first industrial hygiene survey in November 2012, except in 

flavoring and packaging which showed an increase during our April 2017 visit. The packaging 

and flavoring areas had higher levels of diacetyl, 2,3-pentanedione, 2,3-hexanedione, TVOCs, 

CO, and CO2 compared to other areas of the facility. We observed the highest levels of TVOCs, 

CO, and CO2 in the flavoring room. CO levels exceeded the NIOSH ceiling limit of 200 ppm 

inside the flavoring room grinder enclosure where employees should not be during operation. 

Measured dust concentrations in 2012 were below OSHA and ACGIH occupational exposure 

limits. 

Enclosing the entire mezzanine level of packaging was the most significant modification made 

to the facility since November 2012. The alpha-diketone concentrations were generally lower 

in the packaging mezzanine, which can be directly attributed to the additional ventilation added 

to the enclosure. Given the production volume increase of 70% since 2012, the mezzanine 

enclosure and added ventilation had the intended effect. However, the production volume 

increases and installation of additional packaging equipment made it difficult to discern the 

full impact of the mezzanine enclosure and ventilation on the rest of the production area. For 

instance, the concentrations in the rest of packaging remained relatively stable between 2012 

and 2017. The production offices were served by air-handling units that pulled their supply 

air from packaging. This ventilation configuration results in production offices having similar 

airborne concentrations of alpha-diketones as the adjacent packaging area. 
Page 48 Health Hazard Evaluation Report 2012-0170-3372

Employees had occupational lung morbidity associated with high diacetyl and 

2,3-pentanedione exposures, which were not limited to the flavoring room. Continuation of 

the medical surveillance program that includes health questionnaires and breathing tests (e.g., 

spirometry) is important to screen for respiratory symptoms or abnormalities in employees. 

Also, the systematic analysis of aggregate medical tests and symptoms over time is important 

to look for trends and possible risk factors for disease that can help prioritize interventions to 

prevent work-related lung diseases in employees.

Recommendations 

On the basis of our findings, we recommend the actions listed below. We encourage this 

coffee roasting, flavoring, packaging facility to use a labor-management health and safety 

committee or working group to discuss our recommendations and develop an action plan. 

Our recommendations are based on an approach known as the hierarchy of controls. This 

approach groups actions by their likely effectiveness in reducing or removing hazards. In 

most cases, the preferred approach is to eliminate hazardous materials or processes and 

install engineering controls to reduce exposure or shield employees. Until such controls 

are in place, or if they are not effective or feasible, administrative measures and personal 

protective equipment might be needed. 

Engineering Controls

Engineering controls reduce employees’ exposures by removing the hazard from the process 

or by placing a barrier between the hazard and the employee. Engineering controls protect 

employees effectively without placing primary responsibility of implementation on the 

employee. 

1. Continue working with a qualified ventilation contractor to improve existing LEV

systems and install additional systems throughout the production space. Any new 

LEV systems should be targeted at specific points along production lines to capture 

alpha-diketones at their source. 

a. In flavoring, add dampers to the LEV system attached to Exhaust Fan 1 in the 

flavoring room to allow for better balancing of air flows. Consider closing off 

the exhaust registers behind the flavoring barrel storage to allow for some (or 

more) exhaust flow at the flavor pumping station. Add curtains or clear plastic 

panels around the barrel mixing station in the flavoring room to better enclose 

the process and improve the capture effectiveness. Consider adding a ventilated 

enclosure on the bench where the flavorings are weighed and connect it to the 

Exhaust Fan 1 local exhaust system in the flavoring room. Also, continue working 

to tighten the grinder enclosure, including the addition of flexible skirting around 

the bottom and ensure the door remains closed. 

b. In packaging, enclose the new grinder serving lines 5 and 6. Tighten the existing 

grinder enclosure, including the addition of flexible skirting around the bottom. 

Ensure that the doors on both grinder enclosures always remain closed. Install 
Health Hazard Evaluation Report 2012-0170-3372 Page 49

LEV in areas where rework is done and investigate product lines to determine 

other areas where LEV may be appropriate. 

2. Add dilution ventilation through the addition of outdoor air in areas where LEV is not 

feasible or cannot reduce concentrations below NIOSH RELs. Ensure that outdoor air 

is supplied from an area free of contamination from existing exhaust systems. 

3. Add markings on the flavoring room and grinding/packaging area grinder enclosure 

static pressure (magnehelic) gauges to indicate the range of acceptable readings. 

Consider moving the gauges further down into the enclosures to better indicate 

enclosure performance. A lower level would also prevent the operator from needing a 

ladder to accurately read the gauge. 

4. Continue to operate the grinding/packaging mezzanine variable frequency drives 

(VFDs) at 30 Hz for the supply fans and 60 Hz for the exhaust fans, as we left them 

on April 13, 2017. These new settings should properly maintain the mezzanine under 

negative pressure compared to the grinding/packaging space. These VFD settings 

may need to be evaluated and readjusted as additional ventilation changes are made. 

5. Modify existing ventilation systems serving the production offices, breakroom, and 

locker rooms so that supply air originates from outside the plant. Ensure that no air 

from the production area is recirculated into those areas. 

6. Conduct follow-up air sampling to verify that the modifications have been effective 

in reducing alpha-diketone exposures below the NIOSH RELs. If diacetyl and 

2,3-pentanedione concentrations are not maintained below the RELs, additional 

engineering controls may be necessary.

Administrative Controls

Administrative controls are employer-dictated work practices and policies implemented 

to reduce or prevent hazardous exposures. Their effectiveness depends on employer 

commitment and employee acceptance. Regular monitoring and reinforcement are necessary 

to ensure that policies and procedures are followed consistently.

1. Periodically clean the roasters’ exhausts in accordance with manufacturer instructions 

to remove chaff build up to reduce a fire hazard and to improve the efficiency, energy 

usage, and roaster performance. 

2. Include roaster exhaust checks and any future local exhaust systems in a preventive 

maintenance schedule to ensure they operate appropriately.

3. Eliminate the use of compressed air and dry sweeping as much as possible during 

cleaning. Instead, use a vacuum system with a high-efficiency particle air filter and wet 

methods whenever possible. 

4. Ensure employees understand potential hazards (e.g., diacetyl, 2,3-pentanedione, 

CO, CO2, dust) in the workplace and how to protect themselves. OSHA’s Hazard 

Communication Standard, also known as the “Right to Know Law” [29 CFR 
Page 50 Health Hazard Evaluation Report 2012-0170-3372

1910.1200] requires that employees are informed and trained on potential work hazards 

and associated safe practices, procedures, and protective measures. 

5. Ensure employees are educated to consider the risks of further exposure if they 

develop lower respiratory symptoms (e.g., cough, shortness of breath, wheezing) 

that are progressive and severe in degree. Employees should report new, persistent, 

or worsening symptoms to their personal healthcare providers and to a designated 

individual at this workplace. Employees with new, persistent, or worsening symptoms 

should share this report with their healthcare providers.

Personal Protective Equipment

The effectiveness of personal protective equipment in the form of respiratory protection in 

controlling respiratory exposures depends on avoiding breakdowns in implementation that 

result in insufficient protection. Proper use of respiratory protection (respirators) requires a 

comprehensive respiratory protection program and a high level of employee and management 

involvement and commitment to assure that the right type of respirator is chosen for each 

hazard, respirators fit users and are maintained in good working order, and respirators are 

worn when they are needed. Supporting programs such as training, change-out schedules, 

and medical assessment might be necessary. Respirators should not be the sole method for 

controlling hazardous inhalation exposures. Rather, respirators should be used until effective 

engineering and administrative controls are in place.

1. Until engineering and administrative controls are in place, respiratory protection for 

diacetyl and 2,3-pentanedione should continue to be used to reduce exposures to alphadiketones. The choice of respirator should be guided by personal exposure sampling 

for diacetyl and 2,3-pentanedione. Respirators have assigned protection factors 

(APFs). APF refers to the highest level of protection a properly selected respirator 

can provide. For instance, air-purifying half-face respirators have an of 10, and airpurifying full-face respirators have an APF of 50. Powered-air purifying respirators 

have APFs of 25, 50, or 1,000. The OSHA APFs can be found in Table 1 of OSHA 

Respiratory Protection Standard at https://www.osha.gov/laws-regs/regulations/

standardnumber/1910/1910.134

Based on a REL for diacetyl of 5 ppb:

● a properly fit-tested half-face respirator with an APF of 10 and organic vapor 

cartridges would be protective for a diacetyl concentration up to 50 ppb (10 APF x 5 

ppb =50 ppb)

● a properly fit-tested half-face respirator with an APF of 50 and organic vapor 

cartridges would be protective for a diacetyl concentration up to 250 ppb of diacetyl 

(50 APF x 5 ppb = 250 ppb)

● a properly fit-tested PAPR with an APF of 1000 and organic vapor cartridges would 

be protective for a diacetyl concentrating up to 5000 ppb of diacetyl (1000 APF x 5 

ppb = 5000 ppb)
Health Hazard Evaluation Report 2012-0170-3372 Page 51

Based on a REL for 2,3-pentanedione of 9.3 ppb:

● a properly fit-tested half-face respirator with an APF of 10 and NIOSH-certified 

organic vapor cartridges would be protective for a 2,3-pentanedione concentration 

up to 93 ppb (10 APF x 9.3 ppb = 93 ppb)

● a properly fit-tested half-face respirator with an APF of 50 and NIOSH-certified 

organic vapor cartridges would be protective for a 2,3-pentanedione concentration 

up to 465 ppb of 2,3-pentanedione (50 APF x 9.3 ppb = 465 ppb)

● a properly fit-tested PAPR with an APF of 1000 and NIOSH-certified organic vapor 

cartridges would be protective for a 2,3-pentanedione concentration up to 9,300 ppb 

of 2,3-pentanedione (1000 APF x 9.3 ppb = 9,300 ppb)

Information on respirators can be found in Chapter 8 of the NIOSH Criteria Document 

[NIOSH 2016a] and in the NIOSH Respirator Selection Logic [NIOSH 2004]. The 

selection of a specific respirator depends on the particular situation and should be made 

only by qualified personnel [NIOSH 2016a]. 

2. Continue to implement a written respiratory protection program as required by OSHA

Respiratory Protection Standard (29 CFR 1910.134), including medical evaluation, 

training, fit testing, maintenance, and use requirements for all employees who use 

respiratory protection. 

3. Continue to make N95 disposable filtering-face piece respirators available for voluntary 

use for protection against green or roasted coffee dust exposure such as during 

emptying burlap bags of green beans into the storage silos, cleaning the roaster exhaust 

system of chaff, emptying the chaff containers, or cleaning the green bean storage area. 

N95 respirators should be available in various sizes, and each potential N95 user should 

receive a copy of Appendix D of the OSHA Respiratory Protection Standardabout 

Appendix D and voluntary use of respirators can be found on the OSHA website at 

https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.134AppD

Please be aware N95s are not protective against alpha-diketones (diacetyl, 

2,3-pentanedione, or 2,3-hexanedione). In cases of dual exposure to dust and alphadiketones, NIOSH-certified organic vapor cartridges (for the alpha-diketones) and 

particulate cartridges/filters (for the dust) would be warranted. 

4. We did not formally assess noise during our visits. A noise survey would be necessary 

to determine the need for hearing protection and inclusion in a hearing conservation 

program. In the interim, continue to offer hearing protection for voluntary use at each 

roaster as well as other production areas

Medical Surveillance

The purpose of a medical surveillance program is to help assure the health of employees 

who have workplace exposures (e.g., diacetyl, 2,3-pentanedione, green coffee beans/dust) 

known to pose risk for potentially serious health conditions such as asthma or obliterative 

bronchiolitis. 
Page 52 Health Hazard Evaluation Report 2012-0170-3372

1. Continue your medical surveillance program for employees who work or assist in 

the production area. As detailed in the NIOSH Criteria Document [NIOSH 2016a], 

a medical surveillance program is recommended for all employees who work in the 

production areas or enter production areas for a total of 40 hours or more per year. 

According to the NIOSH Criteria Document, employees should have baseline medical 

evaluations before they are allowed to work in or enter areas where they might be 

exposed to diacetyl, 2,3-pentanedione, or similar flavoring compounds. The NIOSH 

Criteria Document recommends employees in the medical surveillance program 

be evaluated with a questionnaire (to obtain health and work task information) and 

spirometry (to assess lung function) every six months.

2. If an employee is identified as likely having lung disease from exposure to diacetyl, 

2,3-pentanedione, or a similar flavoring compound, it should be viewed as a sentinel 

event indicating that there was a breakdown in exposure controls, and there is potential 

risk for co-workers. Should this occur, the source of exposure should be identified and 

brought under control. In addition, increased intensity of medical surveillance would 

be required for all employees performing similar job tasks or having similar or greater 

potential for exposure. The NIOSH Criteria Document provides detailed guidance on 

responses to such sentinel events [NIOSH 2016a]. 

Smoking Cessation Program

In a workplace with risk of occupational lung disease, prevention of smoking-related lung 

disease is important and makes the detection of work-related adverse effects easier. We 

recommend implementing a smoking cessation program to assist employees to stop smoking. 

The Centers for Disease Control and Prevention offers tools and resources for setting up a 

smoking cessation program [CDC 2019].
Health Hazard Evaluation Report 2012-0170-3372 Page 53

Appendix A: Tables

Table A1. Alpha-diketone concentrations in headspace of bulk samples of flavorings used during 

the NIOSH walkthrough visit, July/August 2012 

Flavor A Flavor B Flavor C Flavor D

Analyte ppb μg/cc ppb μg/cc ppb μg/cc ppb μg/cc 

bulk bulk bulk bulk

Diacetyl 119,700 1.3 2,620 0.18 59,000 4.0 10,500 0.70

2,3-Pentanedione 1,040,000 83 ND ND 529,000 42 506,000 41

2,3-Hexanedione 82,000 7.5 ND ND 42,500 3.9 55,500 5.1

Note: NIOSH=National Institute for Occupational Safety and Health; ppb=parts per billion; μg/

cc=microgram per cubic centimeter; ND=not detected.
Page 54 Health Hazard Evaluation Report 2012-0170-3372

Table A2. Alpha-diketone concentrations measured with evacuated canisters in parts per 

billion, NIOSH walkthrough visit, July/August 2012

Analyte Sample Location Date Concentration 

Type (ppb)

Diacetyl Personal Flavoring Specialist 8/1/2012 160

Diacetyl Personal Flavoring Mixer 160

Diacetyl Personal Flavoring Grinder/Packer Operator 130

Diacetyl Personal Flavoring Specialist 8/2/2012 260

Diacetyl Personal Flavoring Mixer 260

Diacetyl Personal Flavoring Grinder/Packer Operator 170

Diacetyl Personal Flavoring Packer Helper 130

Diacetyl Personal Flavoring Packer Helper 230

Diacetyl Area Flavoring Grinder 8/1/2012 210

Diacetyl Area Flavoring Mixing 8/2/2012 400

Diacetyl Area Flavoring Room Mezzanine 310

Diacetyl Area Outside Flavoring Room Entrance 170

Diacetyl Area Roaster #2 14

Diacetyl Area Green Beans Warehouse 18

2,3-Pentanedione Personal Flavoring Specialist 8/1/2012 530

2,3-Pentanedione Personal Flavoring Mixer 460

2,3-Pentanedione Personal Flavoring Grinder/Packer Operator 180

2,3-Pentanedione Personal Flavoring Specialist 8/2/2012 280

2,3-Pentanedione Personal Flavoring Mixer 570

2,3-Pentanedione Personal Flavoring Grinder/Packer Operator 140

2,3-Pentanedione Personal Flavoring Packer Helper 110

2,3-Pentanedione Personal Flavoring Packer Helper 180

2,3-Pentanedione Area Flavoring Grinder 8/1/2012 650

2,3-Pentanedione Area Flavoring Mixing 8/2/2012 2000

2,3-Pentanedione Area Flavoring Room Mezzanine 650

2,3-Pentanedione Area Outside Flavoring Room Entrance 120

2,3-Pentanedione Area Roaster #2 12

2,3-Pentanedione Area Green Beans Warehouse 11

Note: NIOSH=National Institute for Occupational Safety and Health; ppb=parts per billion.
Health Hazard Evaluation Report 2012-0170-3372 Page 55

Table A3. Full-shift personal and area air sampling results by location using OSHA sampling and analytical 

methods, NIOSH industrial hygiene survey, November 2012

Analyte Sample Location N Above LOD Minimum Maximum Above REL 

Type N (%) Concentration Concentration N (%)

(ppb) (ppb)

Diacetyl Personal All Over 5 5 (100%) 49.2 80.1 5 (100%)

Diacetyl Personal Finished Goods Warehouse 5 5 (100%) 4.3 11.7 4 (80%)

Diacetyl Personal Flavoring Room 12 12 (100%) 52.6 96.3 12 (100%)

Diacetyl Personal Greens Warehouse 4 4 (100%) 8.1 9.1 4 (100%)

Diacetyl Personal Offices-All 1 1 (100%) 54.1 54.1 1 (100%)

Diacetyl Personal Offices-Nonproduction Downstairs 1 1 (100%) 7.2 7.2 1 (100%)

Diacetyl Personal Offices-Production Area 3 3 (100%) 39.7 139.5 3 (100%)

Diacetyl Personal Packaging 16 16 (100%) 75.4 166.0 16 (100%)

Diacetyl Personal Quality Control Room 3 3 (100%) 11.7 31.3 3 (100%)

Diacetyl Personal Roasting 9 9 (100%) 15.1 40.1 9 (100%)

Diacetyl Area Finished Goods Warehouse 9 9 (100%) 4.8 16.6 N/A

Diacetyl Area Flavoring 16 16 (100%) 44.0 144.0 N/A

Diacetyl Area Flavoring-Mezzanine 4 4 (100%) 82.7 124.4 N/A

Diacetyl Area Greens Warehouse 11 11 (100%) 5.2 16.4 N/A

Diacetyl Area Maintenance Shop 2 2 (100%) 3.5 10.2 N/A

Diacetyl Area Offices-Nonproduction Downstairs 2 2 (100%) 3.1 4.4 N/A

Diacetyl Area Offices-Nonproduction Upstairs 3 3 (100%) 4.0 4.9 N/A

Diacetyl Area Offices-Production Area 8 8 (100%) 33.8 93.4 N/A

Diacetyl Area Outside 4 4 (100%) 1.9 4.8 N/A

Diacetyl Area Outside of Flavoring Room 4 4 (100%) 7.2 46.5 N/A

Diacetyl Area Packaging 16 16 (100%) 67.9 112.2 N/A

Diacetyl Area Packaging-Mezzanine 5 5 (100%) 102.9 247.2 N/A

Diacetyl Area Quality Control Room 4 4 (100%) 5.5 9.5 N/A

Diacetyl Area Reception 1 1 (100%) 2.6 2.6 N/A

Diacetyl Area Roasting 18 18 (100%) 9.5 50.6 N/A

Diacetyl Area Roasting-Mezzanine 4 4 (100%) 10.9 25.3 N/A

2,3-Pentanedione Personal All Over 5 5 (100%) 31.7 45.0 5 (100%)

2,3-Pentanedione Personal Finished Goods Warehouse 5 0 (0%) <5.2 <5.9 0 (0%)

2,3-Pentanedione Personal Flavoring 12 12 (100%) 79.6 199.0 12 (100%)

2,3-Pentanedione Personal Greens Warehouse 4 0 (0%) <5.2 <5.6 0 (0%)

2,3-Pentanedione Personal Offices-All 1 1 (100%) 18.0 18.0 1 (100%)

2,3-Pentanedione Personal Offices-Nonproduction Downstairs 1 0 (0%) <5.6 <5.6 0 (0%)

2,3-Pentanedione Personal Offices-Production Area 3 3 (100%) 9.5 44.8 3 (100%)

2,3-Pentanedione Personal Packaging 16 16 (100%) 17.9 133.6 16 (100%)

2,3-Pentanedione Personal Quality Control Room 3 2 (67%) <5.4 15.8 2 (67%)

2,3-Pentanedione Personal Roasting 9 3 (33%) <6.0 15.8 3 (33%)

2,3-Pentanedione Area Finished Goods Warehouse 9 0 (0%) <5.1 <5.6 N/A

2,3-Pentanedione Area Flavoring 16 16 (100%) 48.7 273.1 N/A

2,3-Pentanedione Area Flavoring-Mezzanine 4 4 (100%) 150.6 206.4 N/A

2,3-Pentanedione Area Greens Warehouse 11 1 (9%) <5.0 6.0 N/A

2,3-Pentanedione Area Maintenance Shop 2 0 (0%) <5.2 <5.2 N/A

2,3-Pentanedione Area Offices-Nonproduction Downstairs 2 0 (0%) <5.4 <5.6 N/A

2,3-Pentanedione Area Offices-Nonproduction Upstairs 3 0 (0%) <5.3 <5.5 N/A

2,3-Pentanedione Area Offices-Production Area 8 8 (100%) 9.9 46.2 N/A

2,3-Pentanedione Area Outside 4 0 (0%) <4.9 <5.5 N/A

2,3-Pentanedione Area Outside of Flavoring Room 4 4 (100%) 14.5 254.1 N/A

2,3-Pentanedione Area Packaging 16 16 (100%) 23.0 78.3 N/A

2,3-Pentanedione Area Packaging-Mezzanine 5 5 (100%) 28.4 190.6 N/A

2,3-Pentanedione Area Quality Control Room 4 0 (0%) <4.9 <7.0 N/A

2,3-Pentanedione Area Reception 1 0 (0%) <5.3 <5.3 N/A

2,3-Pentanedione Area Roasting 18 9 (50%) <5.3 26.8 N/A

2,3-Pentanedione Area Roasting-Mezzanine 4 2 (50%) <5.3 8.6 N/A

Note: OSHA=Occupational Safety and Health Administration; NIOSH=National Institute for Occupational Safety and Health; 

N=number of samples; Above LOD N (%) =number and percentage of samples above the limit of detection (LOD); Above REL N 

(%) =number and percentage above the NIOSH recommended exposure limit (REL); ppb=parts per billion; N/A=NIOSH RELs are 

specified for personal air samples and area air samples cannot be used for comparison; “All Over” location includes employees that 

were cross-trained and performed tasks at different areas; < indicates below the LOD. 
Page 56 Health Hazard Evaluation Report 2012-0170-3372 Table A4. Full-shift personal and area air sampling results by location using OSHA sampling and analytical methods, NIOSH industrial hygiene survey, April 2017 Analyte Sample Location

N Above LOD Minimum Maximum Above REL 

Type N (%) Concentration Concentration N (%)

(ppb) (ppb)

Diacetyl Personal All Over 3 3 (100%) 30.6 45.2 3 (100%)Diacetyl Personal Flavor Room 7 7 (100%) 100.3 163.8 7 (100%)Diacetyl Personal Offices-Nonproduction Upstairs 1 1 (100%) 3.3 3.3 0 (0%)Diacetyl Personal Packaging 15 15 (100%) 47.2 129.3 15 (100%)Diacetyl Personal Production Office 1 1 (100%) 52.4 52.4 1 (100%)Diacetyl Personal Roasting

2 2 (100%) 21.5 25.1 2 (100%)

Diacetyl Area Finished Goods Warehouse 3 3 (100%) 10.7 22.5 N/ADiacetyl Area Flavoring 21 21 (100%) 93.2 372.0 N/ADiacetyl Area Flavoring-Mezzanine 3 3 (100%) 181.2 251.3 N/ADiacetyl Area Greens Warehouse 3 3 (100%) 11.8 26.8 N/ADiacetyl Area Maintenance Shop 3 3 (100%) 0.8 2.9 N/ADiacetyl Area Offices-Nonproduction Downstairs 6 6 (100%) 1.4 3.2 N/ADiacetyl Area Offices-Nonproduction Upstairs 6 5 (83%) <0.3 2.5 N/ADiacetyl Area Offices-Production Area 15 15 (100%) 16.2 128.9 N/ADiacetyl Area Outside 6 4 (67%) <0.3 17.6 N/ADiacetyl Area Packaging 33 33 (100%) 45.9 146.9 N/ADiacetyl Area Packaging (Old Hold Room) 6 6 (100%) 32.9 109.7 N/ADiacetyl Area Packaging-Mezzanine 9 9 (100%) 67.2 176.2 N/ADiacetyl Area Quality Control Room 3 3 (100%) 3.1 3.9 N/ADiacetyl Area Reception 3 3 (100%) 0.5 0.8 N/ADiacetyl Area Roasting 24 24 (100%) 4.4 50.2 N/ADiacetyl Area Roasting-Mezzanine 3 3 (100%) 7.3 16.9 N/A2,3-Pentanedione Personal All Over 3 3 (100%) 15.8 21.4 3 (100%)2,3-Pentanedione Personal Flavor Room 7 7 (100%) 182.7 899.6 7 (100%)2,3-Pentanedione Personal Offices-Nonproduction Upstairs 1 1 (100%) 1.8 1.8 0 (0%)2,3-Pentanedione Personal Packaging 15 15 (100%) 20.5 161.6 15 (100%)2,3-Pentanedione Personal Production Office 1 1 (100%) 23.9 23.9 1 (100%)2,3-Pentanedione Personal Roasting

2 2 (100%) 9.9 13.5 2 (100%)

2,3-Pentanedione Area Finished Goods Warehouse 3 3 (100%) 4.8 13.7 N/A2,3-Pentanedione Area Flavoring 21 21 (100%) 224.2 1285.3 N/A2,3-Pentanedione Area Flavoring-Mezzanine 3 3 (100%) 724.9 2060.3 N/A2,3-Pentanedione Area Greens Warehouse 3 3 (100%) 5.7 13.7 N/A2,3-Pentanedione Area Maintenance Shop 3 3 (100%) 0.6 7.6 N/A2,3-Pentanedione Area Offices-Nonproduction Downstairs 6 6 (100%) 1.3 10.6 N/A2,3-Pentanedione Area Offices-Nonproduction Upstairs 6 6 (100%) 0.6 8.3 N/A
Health Hazard Evaluation Report 2012-0170-3372 Page 57

Analyte Sample Location

N Above LOD Minimum Maximum Above REL 

Type N (%) Concentration Concentration N (%)

(ppb) (ppb)

2,3-Pentanedione Area Offices-Production Area 15 15 (100%) 8.0 98.1 N/A2,3-Pentanedione Area Outside 6 6 (100%) 0.4 120.9 N/A2,3-Pentanedione Area Packaging 33 33 (100%) 23.0 111.3 N/A2,3-Pentanedione Area Packaging (Old Hold Room) 6 6 (100%) 15.1 109.5 N/A2,3-Pentanedione Area Packaging-Mezzanine 9 9 (100%) 34.6 124.1 N/A2,3-Pentanedione Area Quality Control Room 3 3 (100%) 2.5 3.4 N/A2,3-Pentanedione Area Reception 3 3 (100%) 0.4 2.9 N/A2,3-Pentanedione Area Roasting 24 24 (100%) 2.8 40.4 N/A2,3-Pentanedione Area Roasting-Mezzanine 3 3 (100%) 4.2 14.8 N/A2,3-Hexanedione Personal All Over 3 3 (100%) 0.8 1.2

−

2,3-Hexanedione Personal Flavor Room 7 6 (86%) <0.2 15.7

−

2,3-Hexanedione Personal Offices-Nonproduction Upstairs 1 0 (0%) <0.2 <0.2

−

2,3-Hexanedione Personal Packaging 15 8 (53%) <0.2 4.0

−

2,3-Hexanedione Personal Production Office 1 1 (100%) 1.8 1.8

−

2,3-Hexanedione Personal Roasting

2 2 (100%) 0.6 0.8

−

2,3-Hexanedione Area Finished Goods Warehouse 3 0 (0%) <0.2 <0.2 N/A2,3-Hexanedione Area Flavoring 21 21 (100%) 2.5 53.3 N/A2,3-Hexanedione Area Flavoring-Mezzanine 3 3 (100%) 6.6 48.1 N/A2,3-Hexanedione Area Greens Warehouse 3 0 (0%) <0.2 <0.2 N/A2,3-Hexanedione Area Maintenance Shop 3 1 (33%) <0.2 0.3 N/A2,3-Hexanedione Area Offices-Nonproduction Downstairs 6 0 (0%) <0.2 <0.2 N/A2,3-Hexanedione Area Offices-Nonproduction Upstairs 6 0 (0%) <0.2 <0.2 N/A2,3-Hexanedione Area Offices-Production Area 15 8 (53%) <0.2 1.4 N/A2,3-Hexanedione Area Outside 6 3 (50%) <0.2 2.3 N/A2,3-Hexanedione Area Packaging 33 25 (76%) <0.2 3.7 N/A2,3-Hexanedione Area Packaging (Old Hold Room) 6 5 (83%) <0.2 4.0 N/A2,3-Hexanedione Area Packaging-Mezzanine 9 9 (100%) 1.4 5.8 N/A2,3-Hexanedione Area Quality Control Room 3 0 (0%) <0.2 <0.2 N/A2,3-Hexanedione Area Reception 3 0 (0%) <0.2 <0.2 N/A2,3-Hexanedione Area Roasting 24 11 (46%) <0.2 0.6 N/A2,3-Hexanedione Area Roasting-Mezzanine 3 2 (67%) <0.2 0.4 N/A

Note: OSHA=Occupational Safety and Health Administration; NIOSH=National Institute for Occupational Safety and Health; N=number of samples; Above LOD N (%)=number and percentage of samples above the limit of detection (LOD); Above REL N =number above the NIOSH recommended exposure limit (REL); ppb=parts per billion; N/A= NIOSH RELs are specified for personal air samples and area air samples cannot be used for comparison; “−“indicates that there is currently no REL for 2,3-hexanedione; “All Over” location includes employees that were cross-trained and performed tasks at different areas; < indicates below the LOD.

Table A4. (continued) Full-shift personal and area air sampling results by location using OSHA sampling and analytical methods, NIOSH industrial hygiene survey, April 2017
Page 58 Health Hazard Evaluation Report 2012-0170-3372

Table A5. Diacetyl area air sampling results by location, NIOSH industrial hygiene surveys in 

November 2012 and April 2017

Diacetyl

Location Year Number of Parts per billion (ppb)

samples Minimum Maximum

Finished Goods Warehouse 2012 9 4.8 17

2017 3 11 23

Flavoring 2012 16 44 144

2017 21 93 372

Flavoring-Mezzanine 2012 4 83 124

2017 3 181 251

Greens Warehouse 2012 11 5.2 16

2017 3 12 27

Maintenance Shop 2012 2 3 10

2017 3 0.8 3

Offices-Nonproduction Downstairs 2012 2 3 4

2017 6 1 3

Offices-Nonproduction Upstairs 2012 3 4 4.9

2017 6 <0.3 3

Offices-Production Area 2012 8 34 93

2017 15 16 129

Outside 2012 4 1.5 5

2017 4 <0.3 1.8

Outside-Flavor Room Exhaust 2012 4 7 47

2017 2 8 18

Packaging 2012 15 68 112

2017 33 46 147

Packaging-Old Hold Room 2012 1 78 78

2017 6 33 110

Packaging-Mezzanine 2012 5 103 248

2017 9 67 176

Quality Control Room 2012 4 6 10

2017 3 3 4

Reception 2012 1 3 3

2017 3 0.5 0.8

Roasting 2012 19 10 51

2017 24 4 50

Roasting-Mezzanine 2012 4 11 25

2017 3 7 17

Note: NIOSH=National Institute for Occupational Safety and Health.
Health Hazard Evaluation Report 2012-0170-3372 Page 59

Table A6. 2,3-Pentanedione area air sampling results by location, NIOSH industrial hygiene 

surveys in November 2012 and April 2017

2,3-Pentanedione

Location Year Number of Parts per billion (ppb)

samples Minimum Maximum

Finished Goods Warehouse 2012 9 2.5 2.8

2017 3 5 14

Flavoring 2012 16 49 273

2017 21 224 1285

Flavoring-Mezzanine 2012 4 151 206

2017 3 725 2060

Greens Warehouse 2012 11 3 5

2017 3 6 14

Maintenance Shop 2012 2 2.5 2.6

2017 3 0.6 8

Offices-Nonproduction Downstairs 2012 2 2.7 2.8

2017 6 1 11

Offices-Nonproduction Upstairs 2012 3 2.6 2.8

2017 6 0.6 8

Offices-Production Area 2012 8 10 47

2017 15 8 98

Outside 2012 4 2.4 2.7

2017 4 0.4 6

Outside-Flavor Room Exhaust 2012 4 15 254

2017 2 36 121

Packaging 2012 15 23 78

2017 33 23 111

Packaging-Old Hold Room 2012 1 52 52

2017 6 15 109

Packaging-Mezzanine 2012 5 28 191

2017 9 35 124

Quality Control Room 2012 4 2.5 3.4

2017 3 2.5 3.4

Reception 2012 1 3 3

2017 3 0.4 3

Roasting 2012 19 3 27

2017 24 3 40

Roasting-Mezzanine 2012 4 3 7

2017 3 4 15 

Note: NIOSH=National Institute for Occupational Safety and Health.
Page 60 Health Hazard Evaluation Report 2012-0170-3372 Table A7. Personal and area diacetyl and 2,3-pentanedione concentrations by location using evacuated canisters, NIOSH industrial hygiene survey in November 2012 Above Minimum Maximum Analyte Sample Location N LOD N Concentration Concentration Type (%) (ppb) (ppb) Diacetyl Personal All Over 2 2 (100%) 67.1 86.8 Diacetyl Personal Flavoring Room/Grinding Area 6 6 (100%) 110.5 323.6 Diacetyl Personal Green Coffee Dumping/Roasting Room 3 3 (100%) 7.9 20.5 Diacetyl Personal Offices-Production Area 1 1 (100%) 86.8 86.8 Diacetyl Personal Packaging/Grinding Area (Unflavored/Straight Coffee) 6 6 (100%) 67.1 142.1 Diacetyl Personal Quality Control Room 3 3 (100%) 8.7 30.8 Diacetyl Personal Warehouse 6 6 (100%) 2.4 10.3 Diacetyl Area Flavoring Room/Grinding Area 8 8 (100%) 126.3 323.6 Diacetyl Area Green Coffee Dumping/Roasting Room 6 5 (83%) <4.5 17.4 Diacetyl Area Maintenance Shop 1 1 (100%) 3.9 3.9 Diacetyl Area Offices-Production Area 2 2 (100%) 41.8 69.5 Diacetyl Area Outside Flavoring Exhaust 2 2 (100%) 13.4 25.3 Diacetyl Area Packaging/Grinding Area (Unflavored/Straight Coffee) 6 6 (100%) 86.8 292.0 Diacetyl Area Quality Control Room 1 1 (100%) 7.1 7.1 Diacetyl Area Warehouse 4 4 (100%) 2.4 8.7 2,3-Pentanedione Personal All Over 2 2 (100%) 42.0 56.0 2,3-Pentanedione Personal Flavoring Room/Grinding Area 6 6 (100%) 56.0 310.0 2,3-Pentanedione Personal Green Coffee Dumping/Roasting Room 3 2 (67%) <3.8 11.0 2,3-Pentanedione Personal Offices-Production Area 1 1 (100%) 54.0 54.0 2,3-Pentanedione Personal Packaging/Grinding Area (Unflavored/Straight Coffee) 6 6 (100%) 16.0 96.0 2,3-Pentanedione Personal Quality Control Room 3 2 (67%) <3.2 20.0 2,3-Pentanedione Personal Warehouse 6 1 (17%) <3.2 5.0 2,3-Pentanedione Area Flavoring Room/Grinding Area 8 8 (100%) 69.0 240.0 2,3-Pentanedione Area Green Coffee Dumping/Roasting Room 6 2 (33%) <3.4 5.0 2,3-Pentanedione Area Maintenance Shop 1 0 (0%) <3.4 <3.4 2,3-Pentanedione Area Offices-Production Area 2 2 (100%) 25.0 44.0 2,3-Pentanedione Area Outside Flavoring Exhaust 2 2 (100%) 15.0 76.0 2,3-Pentanedione Area Packaging/Grinding Area (Unflavored/Straight Coffee) 6 6 (100%) 17.0 220.0 2,3-Pentanedione Area Quality Control Room 1 0 (0%) <3.2 <3.2 2,3-Pentanedione Area Warehouse 4 1 (25%) <3.2 4.0 Note: NIOSH=National Institute for Occupational Safety and Health; N=number of samples; Above LOD N (%) =number and percentage of samples above the limit of detection (LOD); ppb=parts per billion.
Health Hazard Evaluation Report 2012-0170-3372 Page 61 Table A8. IOM gravimetric air sampling results for inhalable dust by location at coffee roasting facility, NIOSH industrial hygiene survey, November 2012 Above Minimum Maximum Sample Location LOD Concentration Concentration Type N N (%) (mg/m3) (mg/m3) Personal All Over 2 2 (100%) 0.3 0.3 Personal Flavoring Room/Grinding Area 1 1 (100%) 1.1 1.1 Personal Green Coffee Dumping/Roasting Room 8 8 (100%) 1.0 2.7 Personal Packaging/Grinding Area (Unflavored coffee) 3 2 (67%) <0.3 0.6 Personal Quality Control Room 1 0 (0%) <0.2 <0.2 Personal Warehouse 10 8 (80%) <0.3 14.9 Area Flavoring Room/Grinding Area 19 3 (16%) <0.3 0.5 Area Green Coffee Dumping/Roasting Room 20 17 (85%) <0.3 1.2 Area Maintenance Shop 2 1 (50%) <0.3 0.5 Area Offices-Nonproduction† 7 1 (14%) <0.3 0.4 Area Offices-Production† 6 1 (17%) <0.3 0.4 Area Outside 4 2 (50%) <0.3 232.5 Area Outside Flavoring Exhaust 3 2 (67%) <0.3 0.3 Area Packaging/Grinding Area (Unflavored Coffee) † 21 7 (33%) <0.3 0.7 Area Quality Control Room 4 1 (25%) <0.3 0.4 Area Warehouse† 20 4 (20%) <0.3 0.7 Note: NIOSH=National Institute for Occupational Safety and Health; N=number of samples; Above LOD N (%) =number and percentage of samples above the limit of detection (LOD); mg/m3=milligram per cubic meter. †Offices-Nonproduction includes reception area; warehouse includes the greens warehouse and finished goods warehouse; offices-production category includes corridor, break room, and maintenance room; grinding/packaging area includes the tea machine and hold room.
Page 62 Health Hazard Evaluation Report 2012-0170-3372

Table A9. Instantaneous* evacuated canister pre-and post-shift background air sampling 

results, NIOSH industrial hygiene survey, April 2017

 Concentrations in parts per billion (ppb)

4/11/2017 4/12/2017 4/13/2017

Location Analyte AM PM AM PM AM PM

Flavoring Diacetyl 157.9 125.7 157.9 97.3 86.0 82.9

2,3-Pentanedione 174.9 88.3 228.5 259.1 91.2 76.1

2,3-Hexanedione 12.9 2.9 9.4 4.7 9.4 8.6

Packaging Diacetyl 173.3 123.9 91.7 94.7 57.5 63.9

2,3-Pentanedione 104.7 63.2 49.7 50.1 24.6 25.4

2,3-Hexanedione 4.6 2.8 4.7 3.6 2.0 2.3

Quality Control Room Diacetyl 6.9 9.5 20.6 14.4 6.3 8.9

2,3-Pentanedione 6.3 5.8 7.5 10.2 3.8 4.9

2,3-Hexanedione 0.9 0.9 0.9 1.0 1.0 3.0

Roasting Diacetyl 24.3 6.8 9.3 16.8 14.1 11.3

2,3-Pentanedione 15.6 3.1 3.7 8.0 4.4 3.8

2,3-Hexanedione 0.9 0.9 0.6 1.0 0.9 0.9

Warehouses Diacetyl 29.8 24.5 20.4 12.8 24.5 9.9

2,3-Pentanedione 18.5 11.6 8.3 6.1 15.4 4.6

2,3-Hexanedione 2.6 1.5 0.9 0.9 0.9 0.9

Note: NIOSH=National Institute for Occupational Safety and Health.

*Sampling duration approximately 30 seconds.
Health Hazard Evaluation Report 2012-0170-3372 Page 63 Table A10. Alpha-diketone concentrations in headspace of bulk samples of flavorings collected during the second NIOSH industrial hygiene survey, April 2017. Diacetyl Diacetyl 2,3-Pentanedione 2,3-Pentanedione 2,3-Hexanedione 2,3-Hexanedione Sample ppb ug/cc Bulk ppb ug/cc Bulk ppb ug/cc Bulk Flavor E 283.5 0.04 507.7 0.08 ND ND Flavor F 1181.4 0.16 1161.6 0.19 ND ND Flavor G 75.4 0.01 294.9 0.05 ND ND Flavor H 99.2 0.01 502.6 0.08 ND ND Flavor I 154.3 0.02 3348.8 0.53 ND ND Flavor J ND ND 1391.8 0.22 ND ND Flavor K 648.9 0.09 4778.9 0.76 286.2 0.05 Flavor L 105.6 0.01 389.4 0.06 ND ND Flavor M ND ND 441.6 0.07 ND ND Note: NIOSH=National Institute for Occupational Safety and Health; ND=not detected.
Page 64 Health Hazard Evaluation Report 2012-0170-3372

Table A11. Real-time TVOC measurements, NIOSH industrial hygiene survey, November 2012

TVOCs (ppb)

Location Location Description Mean Min Max

Finished Goods Warehouse Right and left side of warehouse 275 13 855

Flavoring On top of ribbon elevator 1968 776 10667

Small batch barrel flavoring station 2258 1091 4530

Outside flavoring room exhaust 530 0 11353

Greens Warehouse Loading dock 62 0 1369

Beside door into roasting room 068 0 190

Offices – Non-production 2nd floor hallway 103 13 208

Offices-Production Area Breakroom 595 240 16164

Packaging Lines - 5 & 6 1324 681 6857

Lines 7-8 2103 1122 19058

Mezzanine 2604 861 57800

Hand Pack 1197 634 1923

Quality Control Room Table in center of room 0 135 7979

Roasting Roaster Line 1 343 3 7717

Roaster Line 3 242 69 965

Roaster Line 4 522 252 1302

Mezzanine 161 31 572

Back wall of Roasting Room 228 45 495

Note: NIOSH=National Institute for Occupational Safety and Health; TVOCs=total volatile organic compounds; ppb=parts 

per billion; min=minimum value; max=maximum value.
Health Hazard Evaluation Report 2012-0170-3372 Page 65 Table A12. Real-time TVOC measurements, NIOSH industrial hygiene survey, April 2017 TVOCs (ppb) Location Location Description Mean Min Max Finished Goods Warehouse Middle of warehouse space 2,397 991 4,382 Flavoring Inside grinder enclosure 17,737 0 342,500 On top of ribbon elevator 9,933 0 202,500 Small batch barrel flavoring station 12,488 2,692 165,900 Offices-Production Area Production manager office 875 324 1,518 Packaging Beside new grinder lines - 5 & 6 2,408 7 4,096 Near new grinder between operator panels - 1 & 6 3,641 8 7,147 Inside grinder enclosure - 7 & 8 4,130 11 11,786 Near grinder enclosure - 7 & 8 2,604 6 4,789 Inside enclosed mezzanine 6,581 741 28,556 Stairs just outside door of mezzanine 3,733 13 5,706 Roasting Roaster 3 dump station 425 0 1625 Roaster 1 operator desk 241 0 1,424 Roaster 2 operator desk 966 3 2,904 Note: NIOSH=National Institute for Occupational Safety and Health; TVOCs=total volatile organic compounds; ppb=parts per billion; min=minimum value; max=maximum value.
Page 66 Health Hazard Evaluation Report 2012-0170-3372 Table A13. Real-time total dust measurements, NIOSH industrial hygiene survey, November 2012 Total Dust (mg/m3) Location Location Description Mean Min Max Finished Goods Warehouse Right side and Left side of Warehouse 0.02 0 1.68 Flavoring Line 4 Packaging Machine 0.03 0.02 0.23 Greens Warehouse Loading dock 0.15 0 3.77 Beside door into roasting room 0.03 0.02 0.08 Packaging Lines - 5 & 6 0.06 0.04 0.28 Lines 7-8 0.15 0.08 0.56 Tea Machine 0.04 0.02 0.56 Hand Pack 0.05 0.04 0.11 Quality Control Room Table in center of room 0.15 0.01 2.05 Roasting Roaster Line 1 0.16 0.02 1.35 Roaster Line 3 0.56 0.13 6.44 Roaster Line 4 1.59 0.22 9.36 Mezzanine 0.49 0.02 9.20 Back wall of Roasting Room 1.35 0.09 4.95 Note: NIOSH=National Institute for Occupational Safety and Health; mg/m3= milligrams per cubic meter; min=minimum value; max=maximum value.
Health Hazard Evaluation Report 2012-0170-3372 Page 67 Table A14. Real-time CO and CO2 measurements, NIOSH industrial hygiene survey, April 2017 CO (ppm) CO2 (ppm) Location Location Description Mean Min Max Mean Min Max Finished Goods Warehouse Middle of warehouse space 12.0 5.7 22.1 586.7 531.0 1,102.0 Flavoring Inside grinder enclosure 59.6 5.6 500.0 1,183.0 810.0 4,636.0 On top of ribbon elevator 33.8 20.6 111.7 951.3 804.0 1,819.0 Small batch barrel flavoring station 1.1 0.0 21.2 893.4 724.0 1,048.0 Offices-Production Area Production manager office 30.5 14.7 48.3 892.6 784.0 1,187.0 Outside Near flavoring room air intake/exhaust 5.2 0.0 27.2 445.4 237.0 611.0 Packaging Beside new grinder lines - 5 & 6 35.6 19.1 69.9 775.6 516.0 947.0 Near new grinder between operator panels - 1 & 6 28.6 20.0 60.9 806.0 640.0 1,028.0 Inside grinder enclosure - 7 & 8 31.8 8.9 148.2 824.4 672.0 1,083.0 Near grinder enclosure - 7 & 8 36.6 19.0 104.7 801.1 610.0 1,152.0 Packaging-Mezzanine Inside enclosed mezzanine 19.1 10.7 55.5 704.9 558.0 1,236.0 Stairs just outside door of mezzanine 25.1 15.7 32.7 791.2 633.0 961.0 Roasting Roaster 3 dump station 5.3 1.9 11.9 470.6 426.0 536.0 Roaster 1operator desk 1.9 0.7 3.4 431.2 387.0 475.0 Roaster 2 operator desk 4.6 0.6 13.0 515.1 454.0 722.0 Roaster 4 operator desk 4.2 1.9 11.9 485.0 456.0 530.0 Note: NIOSH=National Institute for Occupational Safety and Health; CO=carbon monoxide; CO2= carbon dioxide; ppm=parts per million; min=minimum value; max=maximum value.
Page 68 Health Hazard Evaluation Report 2012-0170-3372

Table A15. Ventilation measurements, NIOSH industrial hygiene survey, November 2012

Outdoor Air Supply

Flow

Type Size (feet) (CFM) Location

Flavoring Room

A/C Grille # 1 1.5 x 2.0 130

A/C Grille # 2 1.5 x 2.0 190 About 15 feet high along west wall. Numbers are from

A/C Grille # 3 1.5 x 2.0 370 south to north along duct

A/C Grille # 4 1.5 x 2.0 460

A/C Grille # 5 1.5 x 2.0 440

TOTAL 1590

Roasting Room and Maintenance Shop

Makeup Air #1 1.5 x 2.0 1530 About 6 feet high along east wall. Numbers are from 

Makeup Air #2 1.5 x 2.0 1230 south to north in roasting room

Makeup Air #3 1.5 x 2.0 3120

Makeup Air #4 1.5 x 2.0 2880 About 6 feet high on east wall of the Maintenance Shop

TOTAL 8760

Exhaust Air to Outside

Flow

Type Size (feet) (CFM) Location

Flavoring Room

Fan 4 x 2 110 8 feet high on outside wall between grinder and packaging machine 

Fan 2 x 2 3600 27 feet high on outside wall, 43 feet from west wall

Fan 2 x 2 1250 11 feet high on outside wall, 27 feet from east wall

LEV 0.92 x 0.96 60 Hood over large batch flavoring station carboy 

LEV 0.66 diameter 180 Duct from new automatic batch flavoring machine

LEV 0.5 diameter 190 Duct for grinder enclosure

LEV 2 x 2 240 Hood about 28.5 inches above 55 gallon drum of flavoring 

Exhaust duct 0.33 x 0.66 100 Grille on duct behind flavoring barrel storage racks 

Exhaust duct 0.33 x 0.66 210 Grille on duct behind flavoring barrel storage racks

Exhaust duct 0.33 x 0.66 165 Grille on duct behind flavoring barrel storage racks

LEV 0.33 diameter 145 Duct pulling air from the bottom flavoring storage cabinet

LEV 0.33 diameter 90 Duct pulling air from the top flavoring storage cabinet

LEV 0.33 diameter 70 Duct at scale for flavorings used at small batch barrels

LEV 7.8 x 1.2 560 Hood above small batch barrel flavoring station

TOTAL 6970

Roasting Room*

Fan 3 x 3 8550 Eastern fan near ceiling on north outside wall 

Fan 1.75 x 1.75 420 Western fan near ceiling on north outside wall 

TOTAL 8970

Grinding/Packaging Room

LEV 1.0 diameter 705 Duct for grinder enclosure nearest Flavoring Room

LEV 1.0 diameter 785 Duct for grinder enclosure nearest to Finished Goods Warehouse

TOTAL 1490†

QC Room

LEV 0.5 diameter 120 Exhaust hood over stove and roasters

Note: A/C=air-conditioning; LEV=local exhaust ventilation; CFM=cubic feet per minute.

*We were unable to measure airflow through the afterburners in the roasting room or determine the sources of the combustion 

air. We made no attempt to control the use of afterburners as we collected our ventilation measurements, but instead allowed the 

afterburners to operate as normal. Thus, we do not understand how afterburner operation and performance may have affected the 

results presented in the table.

†Represents the total airflow measured from the two grinding enclosures which is likely an underestimation due to difficulty accessing 

the duct entry points with the rotating vane anemometer.
Health Hazard Evaluation Report 2012-0170-3372 Page 69

Table A16. Variable frequency drive (VFD) settings tested during NIOSH ventilation 

assessment

VFD Setting Hz (Supply/Exhaust) Pressurization Direction (smoke)

42/42 Mezzanine neutral to grinding room

25/54 Mezzanine strongly negative to grinding room

35/54 Mezzanine moderately negative to grinding room

10/54 Mezzanine strongly negative to grinding room

30/60 Mezzanine strongly negative to grinding room

Note: NIOSH=National Institute for Occupational Safety and Health.

Table A17. Estimated flow rates for exhausted hoods, NIOSH ventilation assessments

Estimated Estimated 

Exhaust Fan Location Flow (cfm) Flow (cfm)

April 2017 November 2012

1 Barrel mixing station-left exhaust 120

1 Barrel mixing station-left center exhaust 135 560

1 Barrel mixing station-right center exhaust 175 combined

1 Barrel mixing station-right exhaust 205

1 Flavor weighing station-desk top 60 70

1 Flavor cabinet storage exhaust upper 80 90

1 Flavor cabinet storage exhaust lower 100 145

1 Flavor Pumping station 0 240

1 Grille behind flavoring barrel storage rack - right Not evaluated 162

1 Grille behind flavoring barrel storage rack - center Not evaluated 210

1 Grille behind flavoring barrel storage rack - left Not evaluated 100

2 Flavor pump station-ribbon blender 0 60

2 Enclosed grinder hood 205 190

2 Ribbon blender vent hood Not evaluated 180

Note: NIOSH=National Institute for Occupational Safety and Health; cfm = cubic feet per minute.
Page 70 Health Hazard Evaluation Report 2012-0170-3372

 Table A18. Characteristics of current worker participants in the NIOSH medical

 survey at coffee facility, September 2012 

Variable n=75

Mean age (range), years 35 (18-67)

Median age, years 34

Mean years employed at current plant (range) 2.9 (0.04-9.3)

Mean years employed at current and old plant (range) 4.3 (0.04-25.0)

Race/Ethnicity

 Hispanic n, (%) 52 (69%)

 Caucasian n, (%) 17 (23%)

 Other n, (%) 6 (8%)

Gender 

 Males n, (%) 51 (68%)

 Females n, (%) 24 (32%)

Smoking status

 Current smoker n, (%) 23 (31%)

 Former smoker n, (%) 17 (23%)

 Never smoker n, (%) 35 (47%)

Note: NIOSH=National Institute for Occupational Safety and Health.
Health Hazard Evaluation Report 2012-0170-3372 Page 71 Table A19. Current worker participants current and ever work areas, NIOSH medical survey at coffee facility, September 2012 Medical Medical survey survey Spirometry Spirometry Variable participants participants participants* participants* n=75 n=75 n=69 n=69 Number (%) Number (%) Number (%) Number (%) Principal Location/Department Grinding/packaging OR flavoring room Grinding/packaging room (unflavored) Roasting room Non-production office/reception Production office Flavoring room Warehouse Quality control room All-over† Housekeeping Current 30 (40%) 22 (29%) 15 (20%) 10 (13%) 1 (1%) 8 (11%) 8 (11%) 5 (7%) 5 (7%) 1 (1%) Ever 39 (52%) 32 (43%) 23 (31%) 10 (13%) 4 (5%) 13 (17%) 9 (12%) 5 (7%) 8 (11%) 1 (1%) Current 29 (42%) 21 (30%) 13 (19%) 7 (10%) 1 (1%) 8 (12%) 8 (12%) 5 (7%) 4 (6%) 1 (1%) Ever 37 (54%) 30 (44%) 21 (30%) 7 (10%) 3 (4%) 13 (19%) 9 (13%) 5 (7%) 7 (10%) 1 (1%) Work in or spend some time in: Grinding/packaging room (unflavored) Flavoring room Grinding/packaging AND flavoring room‡ Grinding/packaging OR flavoring room Current 50 (67%) 50 (67%) 37 (49%) 63 (84%) Ever 58 (77%) 54 (72%) 46 (61%) 66 (88%) Current 45 (65%) 44 (64%) 32 (46%) 57 (83%) Ever 52 (75%) 48 (70%) 40 (58%) 60 (87%) Note: NIOSH=National Institute for Occupational Safety and Health. *69 of the 75 participants completed the spirometry testing. †maintenance technicians, inventory personnel, and material handlers. ‡worked or spent time in grinding/packaging room and flavoring room in the same job.
Page 72 Health Hazard Evaluation Report 2012-0170-3372

Table A20. Prevalence of health conditions and work-relatedness reported by participants 

during the previous 12 months at the time of the NIOSH medical survey at coffee facility, 

September 2012

Previous 4 Previous 12 Symptom aggravated

Symptom weeks months by work or better

N=75 N=75 when away from

Number (%) Number (%) work*

Stuffy, itchy, or runny nose 21 (28%) 34 (45%) 12 of 34

Stinging, burning, irritated nose 7 (9%) 9 (12%) 8 of 9

Watery, itchy eyes 20 (27%) 29 (39%) 15 of 29

Stinging, burning, irritated eyes 13 (17%) 16 (21%) 8 of 16

Sinusitis or sinus problems 10 (13%) 19 (25%) 10 of 19

Cough 8 (11%) 12 (16%) 3 of 12

Awoke with chest tightness 3 (4%) 8 (11%) 3 of 8

Awoke with shortness of breath 4 (5%) 8 (11%) 4 of 8

Breathing trouble 8 (11%) 13 (17%) -

 Rarely have trouble breathing - 8 -

 Regular trouble breathing - 5 -

 Breathing never quite right - 0 -

Shortness of breath on level ground or 

walking up a slight hill - 21 (28%) -

 Short of breathing walking with

 people of own age - 9 (12%) -

 Stop for breath when walking at

 own pace on level ground - 2 (3%) -

 Stop for breath after walking

 about a 100 yards or a few minutes† - 5 (7%) -

Chest wheezing or whistling 8 (11%) 15 (20%) 4 of 15

Asthma attack 0 1 (1%) 1 of 1

Flu-like achiness or achy joints 13 (17%) 20 (27%) 6 of 20

Fever or chills 6 (8%) 11 (15%) 0

Usual tiredness or fatigue 13 (17%) 22 (29%) 10 of 22

Skin rash or skin problems 8 (11%) 14 (19%) 7 of 14

Note: NIOSH=National Institute for Occupational Safety and Health.

*Answered “better” to, “When you are away from this plant on days off or on vacation, is the symptom (inserted) the 

same, worse, or better?” or “yes” to, “Is there anything at work that causes or aggravates this symptom (inserted)?” 

†Three participants answered “yes” to the main question (shortness of breath on level ground or walking up a slight 

hill) and the third sub-question (Stop for breath after walking about a 100 yards or a few minutes) but “no” to one or 

both of the first two sub-questions.
Health Hazard Evaluation Report 2012-0170-3372 Page 73

Table A21. Participant-reported physician-diagnosed conditions, NIOSH medical survey at 

coffee roasting, packaging, and flavoring facility, September 2012

Diagnosed

post-hire at coffee

Health condition N=75 company

Number (%) Number

Hay fever or nasal allergies 13 (17%) 5

Eczema, dermatitis, or skin allergy 4 (5%) 2

Gastroesophageal reflux disease 5 (7%) 3

Ever asthma 5 (7%) 1

Current asthma 2 (3%) 1

Chronic bronchitis 3 (4%) 2

COPD* 2 (3%) 1

Heart disease 4 (5%)† 1

Note: NIOSH=National Institute for Occupational Safety and Health.

*Chronic obstructive pulmonary disease. 

†One of four participants only reported the year of diagnosis; we were unable to determine if heart disease diagnosis 

was pre-hire or not.
Page 74 Health Hazard Evaluation Report 2012-0170-3372

Table A22. Disposable respirator usage by task reported by 33 of 75 medical survey 

participants during NIOSH medical survey at coffee roasting, packaging, and flavoring 

facility, September 2012

Ever wore

disposable

Task respirator at Sometimes All the time

facility*

N=33

Dumping green coffee beans 3 1 2

Roasting coffee beans 1 0 1

Grinding unflavored coffee beans 1 0 1

Packaging unflavored coffee in 0 0 0

cardboard boxes

Flavoring coffee 5 2 3

Grinding flavored coffee 4 0 4

Hand packing flavored coffee 4 0 4

Packing flavored coffee in 9 4 5

cardboard boxes

Performing maintenance 4 2 2

During cleaning 12 5 7

Other 10 7 3

Note: NIOSH=National Institute for Occupational Safety and Health.

*33 of 75 participants reported that they had ever worn a disposable respirator at the facility. Participants were 

shown pictures of disposable dust respirators when asked if they had ever worn a disposable respirator at the facility.
Health Hazard Evaluation Report 2012-0170-3372 Page 75

Table A23. Adjusted* comparisons of symptoms and self-reported physician diagnosis among 

NIOSH medical survey participants at coffee facility to U.S. adult population (NHANES III) 

(N=75)

Health condition Observed Expected SMR

Number Number (95% CI)†

Watery, itchy eyes last 12 months 29 24.4 1.2 (0.83-1.70)

Stuffy, itchy, or runny nose last 12 months 34 32.0 1.1 (0.76-1.48)

Sinus problems last 12 months 19 18.4 1.0 (0.66-1.61)

Phlegm 3 consecutive month or more 6 5.0 1.2 (0.55-2.64)

Wheeze last 12 months 15 9.8 1.5 (0.92-2.52)

Shortness of breath on exertion 21 13.2 1.6 (1.04-2.44)

Cough 3 consecutive months or more 4 4.8 0.8 (0.32-2.14)

Chronic bronchitis (physician-diagnosed) 3 2.9 1.0 (0.35-3.03)

Ever asthma (physician-diagnosed)β 5 4.1 1.2 (0.52-2.83)

Current asthma (physician-diagnosed) 2 2.5 0.8 (0.22-2.87)

Note: NIOSH=National Institute for Occupational Safety and Health; NHANES=National Health and Nutrition 

Examination Survey; SMR= standardized morbidity ratio.

*Adjusted for sex, race/ethnicity, age, and smoking categories. 

†We used the most recent NHANES survey available for each comparison. 

‡95% confidence intervals (CIs) that exclude one are statistically significantly different from comparison with US 

adult population and are shown in bold. 

βFour (80%) of five participants ever diagnosed with asthma were diagnosed before they started working at this 

coffee roasting, flavoring, and packaging facility.
Page 76 Health Hazard Evaluation Report 2012-0170-3372

Table A24. Results of lung function testing for current workers, NIOSH medical survey, 

coffee facility, September 2012

Spirometry (N=69)

FEV1 % predicted, mean (range) 97.6 (55.4-130.9)

FVC % predicted, mean (range) 99.9 (60.8-136.9)

FEV1/FVC %, mean (range) 80.5 (51.1-91.6)

FEF25-75% predicted, mean (range) 94.4 (27.1-163.0)

Abnormally low FEF25-75, n (%) 8 (11.6%)

Obstruction, n (%) 5 (7%)

Restriction, n (%) 2 (3%)

Bronchodilator (N=8)

FEV1 or FVC response, overall, n/N (%) 2/8 (25%)

FEV1 or FVC response, baseline normal, n/N (%) 0/1 (0)

FEV1 or FVC response, low FEV1, n/N (%) 0/2 (0)

FEV1 or FVC response, baseline obstruction, n/N (%) 1/3 (33%)

FEV1 or FVC response, baseline restriction, n/N (%) 1/2 (50%)

Diffusing Capacity (N=66)

Low diffusing capacity, n (%) 3 (5%)

Low alveolar volume, n, (%) 5 (6%)

Mannitol Challenge Test (N=45)

Mild increased sensitivity, n (%) 4* (9%)

Moderate increased sensitivity, n (%) 1 (2%)

Note: NIOSH=National Institute for Occupational Safety and Health; FEV1=forced expiratory volume in one 

second; FVC=forced vital capacity; FEF25-75=forced expiratory flow between 25% and 75% of exhaled volume 

(forced mid-expiratory flow).

*Includes a participant with PD-15 above 635 mg but with a greater than 10% drop in FEV1 between mannitol 

doses 6 and 7.
Health Hazard Evaluation Report 2012-0170-3372 Page 77

Table A25. Adjusted* comparisons of spirometric abnormalities among NIOSH medical 

survey participants at coffee facility to U.S. adult population (NHANES III), September 2012

Spirometry Observed Expected SMR 95% CI†

Result Number Number Ratio

Restrictive 2 4.6 0.4 0.1-1.6

pattern

Obstruction 5 1.8 2.7 1.2-6.4

Note: NIOSH=National Institute for Occupational Safety and Health; NHANES=National Health and Nutrition 

Examination Survey; SMR= standardized morbidity ratio.

*Adjusted for gender, race, age, and smoking categories. Restrictive pattern also adjusted for body mass index. 

†95% confidence intervals (CIs) that exclude one are statistically significantly different from comparison with US 

adult population and are shown in bold. 
Page 78 Health Hazard Evaluation Report 2012-0170-3372

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Health Hazard Evaluation Report 2012-0170-3372 Page 87

Keywords: NAICS 311920 (Coffee roasting), Texas, diacetyl, 2,3-pentanedione, 

2,3-hexanedione, flavorings, coffee, roasting, carbon monoxide, carbon dioxide, volatile 

organic compounds (VOCs), asthma, obliterative bronchiolitis, lung disease
Page 88 Health Hazard Evaluation Report 2012-0170-3372

NIOSH Health Hazard Program Description

The Health Hazard Evaluation Program investigates possible health hazards in the workplace 

under the authority of the Occupational Safety and Health Act of 1970 (29 U.S.C. § 669(a)

(6)). The Health Hazard Evaluation Program also provides, upon request, technical assistance 

to federal, state, and local agencies to investigate occupational health hazards and to prevent 

occupational disease or injury. Regulations guiding the Program can be found in Title 42, Code 

of Federal Regulations, Part 85; Requests for Health Hazard Evaluations (42 CPR Part 85).

Disclaimer

The recommendations in this report are made on the basis of the findings at the workplace 

evaluated and may not be applicable to other workplaces.

Mention of any company or product in this report does not constitute endorsement by the 

National Institute for Occupational Safety and Health (NIOSH).

Citations to Web sites external to NIOSH do not constitute NIOSH endorsement of the 

sponsoring organizations or their programs or products. NIOSH is not responsible for the 

content of these Web sites. All Web addresses referenced in this document were accessible as 

of the publication date.

Acknowledgments

Desktop Publisher: Barbara Elbon 

Data Analysis Support: Nicole Edwards, Kathleen Fedan, and Brian Tift

Laboratory Support: Toni Bledsoe, Dru Burns, Brett Green, Kyle Hatcher, Anand Ranpara

Site Visit Team Members: Walter Alarcon, Rachel Bailey, Ana Barbero, Mike Beaty, Randy 

Boylstein, Diana Cale, Cammie Chaumont Menendez, Matthew Duling, Kevin H. Dunn, Nicole 

Edwards, Diana Freeland, Steve Game, Elizabeth Garza, Cara Halldin, Robert Lawrence, Ryan 

LeBouf, Stephen Martin, Anne-Binney McCague, Tia McClelland, Chris Piacitelli, Marcia 

Stanton, Brian Tift

Availability of Report

Copies of this report have been sent to the employer and employees at the facility. The state 

health department and the Occupational Safety and Health Administration Regional Office 

have also received a copy. This report is not copyrighted and may be freely reproduced.

This report is available at http://www.cdc.gov/niosh/hhe/reports/pdfs/2012-0170-3372.pdf.

All other Health Hazard Evaluation Reports may be found at https://www2a.cdc.gov/hhe/

search.asp.

Recommended citation for this report:

NIOSH [2020]. Evaluation of exposures and respiratory health at a coffee roasting, 

flavoring, and packaging facility. By Bailey RL, Duling MG, Martin SB, Stanton ML, 

McClelland TL, LeBouf RF, Edwards NT, Fedan KB, Cox-Ganser JM. Morgantown, WV: U.S. 

Department of Health and Human Services, Centers for Disease Control and Prevention, 

National Institute for Occupational Safety and Health, NIOSH HHE Report No. 2012-

0170-3372.
To receive documents or other information about

occupational safety and health topics, contact NIOSH

Telephone: 1-800-CDC-INFO (1-800-232-4636)

TTY: 1-888-232-6348

email: cdcinfo@cdc.gov

or visit the NIOSH website at http://www.cdc.gov/niosh

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