Health Hazard Evaluation Report 2015-0163-3298 Page 1

Evaluation of exposures and respiratory 

health at a coffee roasting and packaging 

facility.

Report No. 2015-0163-3298

November 2017

Randall J. Nett, MD, MPH

Brie Hawley, PhD

U.S. Department of Health and Human Services

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health
Page 2 Health Hazard Evaluation Report 2015-0163-3298

Contents

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

Abbreviations ...................................... v

Summary.............................................. 1 

Introduction......................................... 2

Background.......................................... 2

Process Description............................. 4 

Methods ............................................... 5 

Results ................................................ 13

Discussion .......................................... 17

Conclusions........................................ 23

Recommendations............................. 23

Appendix A: Tables............................ 27

References.......................................... 35

Acknowledgements........................... 45

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 2015-0163-3298 Page i

We evaluated respiratory health 

and airborne exposures to alphadiketones (diacetyl, 2,3-pentanedione, 

and 2,3-hexanedione), other volatile 

organic compounds, carbon monoxide, 

and carbon dioxide during coffee 

roasting, grinding, and packaging. 

Some employees in the production 

area of the facility had full-shift timeweighted average exposures exceeding 

the NIOSH recommended exposure 

limits for diacetyl and 2,3-pentanedione. 

Additionally, some 15-minute short-term 

exposure samples collected on employees 

performing grinding of roasted coffee 

beans exceeded the recommended NIOSH 

short-term exposure limits for diacetyl 

and 2,3-pentanedione. The highest 

personal carbon monoxide levels were 

observed on production employees while 

grinding 5-pound bags of roasted coffee; 

however, all personal carbon monoxide 

measurements were below the NIOSH 

recommended exposure limit of 35 ppm. 

Eye, nose, and sinus symptoms were the 

most commonly reported symptoms. 

Wheezing was the most commonly 

reported lower respiratory symptom 

and two times as common as expected. 

One of 15 participants had abnormal 

spirometry. We recommend engineering 

controls to mitigate exposure to diacetyl, 

2,3-pentanedione, and carbon monoxide 

near the grinder and roaster. We provide 

several additional means to reduce 

potential employee exposure to diacetyl, 

2,3-pentanedione, and carbon monoxide. 

We also recommend implementing 

administrative controls such as 

modification of work practices, training 

employees about work-place hazards, and 

instituting a medical monitoring program.

Highlights of this Evaluation

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

Health received a request from the management of a coffee roasting and packaging facility 

regarding concerns about exposures to and health effects from diacetyl and 2,3-pentanedione 

during coffee roasting, grinding, and packaging

What We Did

● We visited the coffee processing facility in 

June 2016.

● We collected full-shift (hours), tasks 

(minutes), and instantaneous (seconds) air 

samples to measure air levels of the alphadiketones diacetyl, 2,3-pentanedione, and 

2,3-hexanedione over multiple days.

● We collected roasted coffee beans 

to measure their emission potential 

for diacetyl, 2,3-pentanedione, and 

2,3-hexanedione.

● We measured real-time air levels of total 

volatile organic compounds, carbon 

monoxide, and carbon dioxide.

● We assessed the ventilation system at the 

facility.

● We administered a health questionnaire to 

employees and performed breathing tests. 

What We Found

● On full shift sampling, some employees 

were exposed to diacetyl concentrations 

above the recommended exposure 

limit of 5 parts per billion. The highest 

concentration of diacetyl we measured 

as an average across a full shift was 18.8 

parts per billion. 

● On full shift sampling, some employees 

were exposed to 2,3-pentanedione 

concentrations above the recommended 

exposure limit of 9.3 parts per billion. The 

highest 2,3-pentanedione concentration we measured as an average across a full shift 

was 18.7 parts per billion.
Page ii Health Hazard Evaluation Report 2015-0163-3298

● Levels of diacetyl and 2,3-pentanedione in the air during short-term sampling were 

higher for tasks involving grinding roasted coffee (maximum 70 parts per billion for 

diacetyl and 84.0 parts per billion for 2,3-pentanedione).

● The highest levels of carbon monoxide and total volatile organic compound 

measurements were observed while an employee ground roasted beans for 5-pound 

bags of coffee.

● The two air-handling units kept the air in the production area from entering the café, 

breakroom, and office areas. No exposure levels in the café, breakroom, or office areas 

exceeded the recommended exposure limits for diacetyl or 2,3-pentanedione.

● Eye, nose, and sinus symptoms were the most commonly reported symptoms. 

● Wheezing or whistling in the chest was the most commonly reported lower respiratory 

symptom; two times as many employees reported wheezing as expected. 

● One of 15 participants had mildly abnormal spirometry that did not improve after 

bronchodilator treatment. 

● Three of 15 participants had high exhaled nitric oxide, a marker of allergic airways 

inflammation.

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.

● Install local exhaust ventilation systems at the grinder and auto-fill packaging machine 

to capture diacetyl, 2,3-pentanedione, and carbon monoxide emissions when these 

machines are in use. 

● If possible, increase airflow of downdraft table at the roaster or consider 

installing additional local exhaust ventilation at the roaster to capture diacetyl and 

2,3-pentanedione emissions when the roaster is in use.

● Continue to cover bins of roasted beans to reduce emissions of alpha-diketones, carbon 

monoxide, and carbon dioxide into the air.

● Ensure the continuous operation of the air handling unit in the production space at all 

times during production activities.

● Automate transfer of roasted beans, whenever possible, to minimize manual handling.

● Minimize production tasks that require employees to place their heads directly above or 

inside roasted bean storage bins.

● Follow manufacturer’s guidelines for periodic cleaning of the roasters’ exhausts.

● Conduct follow-up air sampling to verify the modifications have been effective 

in reducing exposures to below the recommended exposure limit for diacetyl and 

2,3-pentanedione.
Health Hazard Evaluation Report 2015-0163-3298 Page iii

● Make N95 disposable filtering-facepiece respirators available for voluntary use 

for protection against dust exposure such as when emptying burlap bags of green 

beans into the storage silos, cleaning the exhaust system of chaff, emptying the chaff 

containers, or cleaning the green bean storage area. 

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

their personal healthcare providers and to a designated individual at the workplace.

● Institute a medical monitoring program for employees who work in the production area.

What Employees Can Do

● Use any local exhaust ventilation as instructed by your employer when it is installed.

● As much as possible, avoid placing your head directly above or inside roasted bean 

storage bins. 

● Follow your employer’s instructions for an alternative method to hand-blending roasted 

coffee beans.

● Some employees might wish to use N95 disposable filtering-facepiece respirators for 

some tasks, such as when emptying burlap bags of green beans into storage containers, 

cleaning the chaff out of the roaster exhaust system, emptying the chaff containers, or 

cleaning the green bean storage area.

● Participate in any personal air sampling offered by your employer.

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

provider and a designated individual at your workplace.

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

employer.
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Health Hazard Evaluation Report 2015-0163-3298 Page v

Abbreviations

μm Micrometer

μg Microgram

°F degrees Fahrenheit

ACGIH® American Conference of Governmental Industrial Hygienists

AHU Air-handling unit

ANSI American National Standards Institute

APF Assigned Protection Factor

AX Area of reactance

CFR Code of Federal Regulations

CO Carbon monoxide

CO2 Carbon dioxide

COHb Carboxyhemoglobin

COPD Chronic obstructive pulmonary disease

DR5-R20 The difference between resistance at 5 and 20 Hertz

FEV1 1-second forced expiratory volume

Fres Resonant frequency

FVC Forced vital capacity

kg/m2 Kilogram per square meter

kPa/(L/s) Kilopascals per liter per second

IDLH Immediately dangerous to life or health

IOM Institute of Occupational Medicine

LOD Limit of detection

LOQ Limit of quantitation

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

OEL Occupational exposure limit

OSHA Occupational Safety and Health Administration

PEL Permissible exposure limit

ppb Parts per billion

ppm Parts per million

R5 Resistance at 5 Hertz

R20 Resistance at 20 Hertz

REL Recommended exposure limit
Page vi Health Hazard Evaluation Report 2015-0163-3298

SMR Standardized morbidity ratio

STEL Short-term exposure limit

TLV® Threshold limit value

TVOC Total volatile organic compound

TWA Time-weighted average

U.S. United States

VOC Volatile organic compound

X5 Reactance at 5 Hertz
Health Hazard Evaluation Report 2015-0163-3298 Page 1

Summary

In September 2015, the Health Hazard Evaluation Program of the National Institute for 

Occupational Safety and Health (NIOSH) received a request from the management of a 

coffee roasting and packaging facility regarding concerns about exposures to and health 

effects from diacetyl and 2,3-pentanedione during coffee roasting, grinding, and packaging. 

In June 2016, we conducted a ventilation assessment, an industrial hygiene survey, and a 

medical survey. The industrial hygiene survey consisted of the collection of air samples and 

bulk samples of coffee for the analysis of diacetyl, 2,3-pentanedione, and 2,3-hexanedione. 

Continuous monitoring instruments were used to monitor total volatile organic compounds, 

carbon monoxide, carbon dioxide, temperature, and relative humidity in specific areas and 

during tasks. We also measured levels of carbon monoxide in employees’ exhaled breath. The 

medical survey consisted of a health questionnaire and breathing tests.

Overall, time-weighted average air levels of diacetyl, 2,3-pentanedione, and 2,3-hexanedione 

were elevated for employees performing duties near the roaster and grinder. Seven of the 

10 personal full-shift air samples were above the NIOSH recommended exposure limit 

for diacetyl of 5 parts per billion, and five of the 10 full-shift air samples were above the 

recommended exposure limit for 2,3-pentanedione. All personal air samples with diacetyl 

and 2,3-pentanedione concentrations above the recommended exposure limits were collected 

on employees with primary job duties in the production area. High full-shift and task-based 

diacetyl and 2,3-pentanedione exposure measurements were observed on employees that 

ground coffee. We observed high instantaneous levels of diacetyl and 2,3-pentanedione 

during grinding. Carbon monoxide and total volatile organic compound levels near the 

grinder increased sharply when an employee ground roasted beans for 5-pound bags of 

coffee. Carbon dioxide levels were low throughout most of the facility.

Mucous membrane symptoms, specifically eye, nose, and sinus symptoms, were the most 

commonly reported symptoms. Wheezing or whistling in the chest was the most commonly 

reported lower respiratory symptom, and was about two times as common as expected 

compared with the US population of the same age, race/ethnicity, sex, and cigarette 

smoking distribution. One of the 15 participants had abnormal spirometry. We recommend 

a combination of engineering and administrative controls to minimize employee exposures. 

We also recommend a medical monitoring program to identify any employees who might 

be developing work-related lung disease (e.g., asthma, obliterative bronchiolitis) and to help 

management prioritize interventions to prevent occupational lung disease. 

 

 

 

 
Page 2 Health Hazard Evaluation Report 2015-0163-3298

Introduction

In September 2015, the National Institute for Occupational Safety and Health (NIOSH) 

received a management request for a health hazard evaluation at a coffee roasting and 

packaging facility. The request concerned potential worker exposure to diacetyl and 

2,3-pentanedione during the coffee roasting, grinding, and packaging processes and potential 

lung damage. In June 2016, we visited the facility to learn more about coffee processing 

and to conduct industrial hygiene and medical surveys. We collected area and personal 

breathing zone air samples for volatile organic compounds (VOCs), including diacetyl, 

2,3-pentanedione, and 2,3-hexanedione. We monitored carbon monoxide (CO), carbon dioxide 

(CO2), and total VOCs. We also conducted a medical survey.

Background

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 [Day et al. 2011; Kanwal et 

al. 2006; Bailey et al. 2015]. Diacetyl, 2,3-pentanedione, other VOCs, and gases such as CO 

and CO2 are naturally produced and released during the coffee roasting process [Duling et al. 

2016; 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 a one-way valve 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 2016]. 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 timeweighted 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 5th percentile) 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 
Health Hazard Evaluation Report 2015-0163-3298 Page 3

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, some evidence showed 

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]. No established occupational exposure 

limits exist for 2,3-hexanedione.

Carbon Monoxide and Carbon Dioxide

CO and CO2 are gases produced by combustion. CO and CO2 are also produced by reactions 

that take place during coffee roasting and are released during and after roasting and grinding, 

a process called off-gassing [Anderson et al. 2003]. 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 2013; Raffel 

and Thompson 2013; Rose et al. 2017]. Occupational exposure limits for CO and CO2 are 

listed in Table 1.

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 can include cough, 

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

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

manufacturing workers and microwave popcorn workers who worked with flavoring 

chemicals or butter flavorings [Kreiss 2013; Kim et al. 2010; Kanwal et al. 2006]. It has 

also been identified in employees at a coffee processing facility that produced unflavored 

and flavored coffee [CDC 2013]. A NIOSH health hazard evaluation at that facility found 

diacetyl and 2,3-pentanedione concentrations in the air that were concerning and identified 

three sources: 1) flavoring chemicals added to roasted coffee beans in the flavoring area; 2) 

grinding unflavored roasted coffee beans and packaging unflavored ground and whole bean 

roasted coffee in a distinct area of the facility, and 3) storing roasted coffee in hoppers, on a 

mezzanine above the grinding/packaging process, to off-gas [Duling et al. 2016]. At the time 

of the health hazard evaluation, workers had excess shortness of breath and obstruction on 

spirometry, both consistent with undiagnosed lung disease. Respiratory illness was associated 

with exposure and not limited to the flavoring areas [Bailey et al. 2015]. However, all 

workers who were diagnosed with obliterative bronchiolitis had worked in the flavoring area. 

To date, no cases of obliterative bronchiolitis have been reported in workers at coffee roasting 

and packaging facilities that produce only unflavored coffee.

Work-related Asthma

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

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

2016; Tarlo and Lemiere 2014; OSHA 2014; Henneberger et al. 2011]. Work-related asthma 
Page 4 Health Hazard Evaluation Report 2015-0163-3298

includes asthma caused by sensitizers, which cause disease through immune (allergic) 

mechanisms, and asthma caused by 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 can 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 work-related asthma [Figley and Rawling 1950; 

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

(develop an immune reaction) to coffee dust can subsequently react to low concentrations 

in the air. Others can experience irritant-type symptoms from exposure to coffee dust 

[Oldenburg et al. 2009].

Process Description

In June 2016, the coffee roasting and packaging facility had 19 employees. Eight employees 

were involved in various administrative tasks which included accounts receivable, customer 

service, inventory control, delivery, equipment repair, graphic design, sales, and farmer 

relations. Five employees worked in the café. The remaining six employees were responsible 

for activities specific to the coffee roasting process. The following describes activities at the 

time of the NIOSH visit in June 2016.

The coffee roasting process involved four main steps, receiving of green beans (unroasted 

coffee beans), roasting green beans, weighing and packaging of roasted beans (whole 

and ground), and shipment or delivery of final product to individual consumers, food 

cooperatives, restaurants, cafés, and markets.

Green beans were received in burlap bags (sometimes lined with plastic) from various 

countries around the world including, but not limited to, Colombia, Guatemala, Mexico, 

and Honduras. Upon arrival at the facility, bags of green beans were stored on pallets either 

on the floor or shelves until they were dispensed into large green bean storage silos. To 

prepare a batch for roasting, a roaster operator dispensed the green beans from the storage 

silo or directly from bags into a container to achieve the proper weight needed for a roast. 

The green beans were then manually emptied into the hopper of the roaster. The green 

beans were automatically conveyed from the hopper into the roasting drum where they were 

heated at a specific temperature and time period until the desired roast was achieved. Time 

and temperature varied among different types of roasts. At the end of each cycle, the roasted 

beans were emptied into a cooling drum where they were slowly mixed to accelerate cooling. 

The cooling drum utilized a downdraft exhaust system that drew air over the roasted beans 

and down into the cooling drum to accelerate cooling. The downdraft system exhausted out 

through the roof. A roaster operator monitored the roasting equipment carefully throughout 

the roasting process. After cooling, the roasted beans were emptied from the cooling drum 

into plastic storage containers. These containers were then manually moved by a roaster 

operator to an area where the storage containers were kept. When not in use, the storage 
Health Hazard Evaluation Report 2015-0163-3298 Page 5

containers were covered and stored until needed for grinding or packaging. 

For packaging of roasted coffee, a production employee moved a container of roasted beans 

near the packaging machine. The roasted beans were pneumatically conveyed into the hopper 

of an automatic auto-fill packaging machine where four different amounts were mainly 

dispensed for packaging: 12-ounces, 1-pound, 3-pounds, and 5-pounds. For ground coffee, 

individual, pre-weighed packages of roasted whole beans were emptied into a grinder. The 

grinder could be adjusted for type of grind (coarse, medium, fine). Packages of both whole 

and ground coffee were heat-sealed and placed on storage shelves or immediately packed for 

shipment or local delivery.

The company took measures to ensure quality of green and roasted beans. The facility had a 

quality control room located in the conference room where roasted beans and brews could be 

prepared and assessed. Roasted beans were packed in the order they were roasted to ensure 

freshness. Several employees engaged in “cupping” one to three days per week to ensure 

quality of roasted coffee.

Various cleaning techniques were used throughout the production area. The chaff collection 

compartment in the roaster was cleaned using a Shop-Vac vacuum three to four times daily 

during roasting activities. Once a week the entire roaster was thoroughly cleaned, including 

the chaff collection compartment, impeller compartment, cooling bin exhaust ducts, and 

vacuum tube. Sweeping and wiping with dry cloths were conducted daily. Sweeping was 

performed on the production floor, and wiping was performed on table tops and equipment 

surfaces. Wet mopping was conducted at least once a week. The grinder was wiped with a 

clean, dry cloth daily. Once a week the filter on the Pneu-Con vacuum loader was vacuumed. 

One employee was involved in repairing of customer’s coffee roasting equipment (roasters, 

grinders, and espresso machines). The company had numerous customers who had their 

own grinding and brewing equipment for the sale of their coffee. This was a service that 

the company offered to their customers. The employee would occasionally work on the 

customer’s machines within the production area.

Employees were not required to wear a company uniform or protective clothing. We did not 

observe employees wearing any respiratory protection for chemicals or dust at the time of our 

visit. Hearing protection was available for voluntary use.

Methods

We visited the coffee roasting and packaging facility in June 2016. We held an opening 

meeting with management and an employee representative; performed a ventilation 

assessment; collected bulk samples and air samples; conducted confidential medical 

interviews; and administered breathing tests. At the conclusion of our site visit we held a 

closing meeting with management and an employee representative. We provided a letter 

detailing our evaluation and preliminary recommendations to management on July 19, 2016.
Page 6 Health Hazard Evaluation Report 2015-0163-3298

1. We had the following objectives for the health hazard evaluation:

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

during coffee processing;

3. Identify process areas or work tasks associated with elevated levels of diacetyl, 

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

4. Measure levels of CO and CO2 throughout the facility;

5. Measure CO levels in employees’ exhaled breath;

6. Assess ventilation systems and the ventilation systems’ effect on exposure levels;

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

and the proportion of those symptoms that were work-related or aggravated by work;

8. Determine if employees had abnormal lung function tests; 

9. Compare employees’ prevalence of lower respiratory symptoms and physiciandiagnosed asthma with expected levels based on general population values.

Industrial Hygiene Survey

Sampling Times for Alpha-Diketones 

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

processes that were the greatest contributors to worker 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 with 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 particular tasks, we collected air samples over several minutes. We also 

conducted instantaneous sampling over seconds to help identify point sources of alphadiketones. 

Air Sampling and Analysis Using Occupational Safety and Health Administration (OSHA) 

Methods 1013/1016

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

2,3-hexanedione on silica gel sorbent tubes during our industrial hygiene survey. The samples 

were collected and analyzed according to the modified OSHA sampling and analytical 

Methods 1013/1016 [OSHA 2008; 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 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 various places throughout the facility. For full-shift sampling, we collected two 

consecutive 3-hour samples and calculated the time-weighted average (TWA) concentration 

from the two samples, assuming the total 6-hour monitoring results reflected a full work 

shift (8-hour) TWA exposure. Although this can introduce some error, it is a conservative 
Health Hazard Evaluation Report 2015-0163-3298 Page 7

approach that is more protective of employees 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, 

but the sampling pump flow rate was 200 mL/min as detailed in OSHA Methods 1013 and 

1016 [OSHA 2008; 2010]. Sampling times were dependent on the duration of the task being 

performed. 

Analyses of the samples were performed in the NIOSH Respiratory Health Division’s 

Organics Laboratory. The samples were extracted for one hour in 95% ethanol:5% water 

containing 3-pentanone as an internal standard. Samples were analyzed using an Agilent 

7890/7001 gas chromatograph/mass spectrometer system operated in selected ion monitoring 

mode for increased sensitivity compared with the traditional flame ionization detector used in 

OSHA Methods 1013 and 1016 [LeBouf and Simmons 2017].

A limit of detection (LOD) is the lowest mass an instrument can measure above background 

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

quantitation (LOQ) is the lowest mass that can be reported with precision; we have a greater 

confidence in the reported result if it is above the LOQ. The LODs were 0.02 micrograms per 

sample (μg/sample) for diacetyl, 2,3-pentanedione, and 2,3-hexanedione. These equate to 0.6 

ppb for diacetyl, 0.5 ppb for 2,3-pentanedione, and 0.5 ppb for 2,3-hexanedione for a typical 

full-shift TWA air sample but varies depending on the volume of sample collected. The 

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

because the air volumes collected during task samples are lower. When the values presented 

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

equate to 2.0 ppb for diacetyl, 1.7 ppb for 2,3-pentanedione, and 1.7 ppb for 2,3-hexanedione 

for a typical full-shift air sample.

Air Sampling and Analysis Using Evacuated Canisters

We collected area full-shift air samples and instantaneous task-based and source air samples 

for VOCs including diacetyl, 2,3-pentanedione, and 2,3-hexanedione using evacuated 

canisters. We also collected instantaneous air samples before and after the work shift 

to determine if air concentrations of alpha-diketones increased over a work shift. The 

evacuated canister sampling setup consisted of a 450-mL evacuated canister equipped to 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 by the 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 control directly at the source of interest. 

The canister air samples were analyzed using a pre-concentrator/gas chromatograph/

mass spectrometer system pursuant to a published method validation study [LeBouf 

et al. 2012], with the following modifications: the pre-concentrator was a Model 7200 

(Entech Instruments, Inc., Simi Valley, CA), and six additional compounds, diacetyl, 

2,3-pentanedione, and 2,3-hexanedione, acetaldehyde, acetonitrile, and styrene, were 
Page 8 Health Hazard Evaluation Report 2015-0163-3298

included. At present, this canister method is partially validated [LeBouf et al. 2012] and 

not considered the standard method. The LODs were 0.78 ppb for diacetyl, 1.08 ppb for 

2,3-pentanedione, and 1.92 ppb for 2,3-hexanedione based on a three-times dilution factor. 

However, LODs are dependent on the pressure inside each canister after the samples have 

been collected, and they might be higher or lower than typical LOD values. 

Bulk Sampling and Headspace Analysis

We used 50-mL sterile polypropylene centrifuge tubes to collect approximately 40-mL 

bulk samples of roasted coffees (whole bean and ground). For headspace analysis of 

alpha-diketones, we transferred 1 gram of solid 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 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.

Continuous (Real-time) Air Sampling

We used a RAE Systems (San Jose, CA) ppbRAE 3000 (Model #PGM-7340) monitor to 

measure levels of total VOCs in the air near the grinder. This sampling was conducted 

to identify when peak levels of total VOCs occurred in the area near the grinder. We also 

collected continuous measurements of CO2, CO, temperature (in oF), and relative humidity 

at the roaster and grinder on both days of our survey, using a TSI Incorporated (Shoreview, 

MN) VelociCalc Model 9555-X Multi-Function Ventilation Meter equipped with a Model 

982 IAQ probe.

We also continuously measured employee personal exposures to CO using a Dräger Pac 7000 

personal single gas detector (Lübeck, Germany). The Drager Pac 7000 was placed in the 

breathing zone of employees and worn by employees while they performed their work duties.

Exhaled CO Measurements

We asked employees to perform a carboxyhemoglobin (COHb) test one or more times 

throughout their shift to measure CO levels in their exhaled breath. This test helps determine 

if employees are exposed to elevated levels of CO potentially associated with coffee 

processing activities. Employees were asked to hold their breath for 15 seconds and then 

exhale through a mouthpiece into a CO monitor. The device then calculated an estimate of 

COHb in blood. Each employee performing the COHb tests was also asked when he or she 

had last smoked cigarettes or used tobacco products, electronic cigarettes, or vaporizers, as 

each of these can cause an increase in exhaled CO.

Exposure Limits

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

(OELs) when evaluating workplace hazards. OELs have been developed by federal agencies 

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

exposures.
Health Hazard Evaluation Report 2015-0163-3298 Page 9

Occupational Safety and Health Administration (OSHA)

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

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 2017]. OSHA short-term exposure limits (STELs) are the legal 

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

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

exist 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 occupational exposure references and recommendations [OSHA 1993; OSHA 

2003], such as the American Conference of Governmental Industrial Hygienists (ACGIH®) 

TLVs® and NIOSH RELs.

American Conference of Governmental Industrial Hygienist (ACGIH®) 

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 threshold limit values (TLVs®) [ACGIH® 2017a]. 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 that 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® 2017a]. Additionally, ACGIH® provides TLV-Ceiling values 

that 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, no TLVTWA or TLV-STEL exists for 2,3-pentanedione. ACGIH® has placed 2,3-pentanedione on the 

2017 list of Chemical Substances and Other Issues Under Study [ACGIH® 2017b]. 

National Institute for Occupational Safety and Health (NIOSH)

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 2010]. NIOSH also provides 

STELs that are 15-minute TWA exposures that should not be exceeded at any time during 

a workday [NIOSH 2010]. Some chemicals have ceiling values that are concentrations 

that should not be exceeded at any time [NIOSH 2010]. 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 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 
Page 10 Health Hazard Evaluation Report 2015-0163-3298

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

additive effects [ACGIH® 2017a]. 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 2016].

Compound

Diacetyl

2,3-Pentanedione

2,3-Hexanedione

Carbon dioxide

Carbon monoxide§

OSHA* ACGIH® NIOSH

PEL TLV STEL REL STEL IDLH

- 10 ppb 20 ppb 5 ppb† 25 ppb -

- - - 9.3 ppb† 31 ppb -

- - - - - -

5,000 ppm 5,000 ppm 30,000 ppm 5,000 ppm 30,000 ppm 40,000 ppm

50 ppm 25 ppm - 35 ppm 200 ppm (ceiling limit)¶ 1,200 ppm

Table 1. Exposure limits for compounds sampled during the NIOSH survey, June 2016.

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

Governmental Industrial Hygienist; 

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

STEL=short-term exposure limit; TLV®=threshold limit value; 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.

§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.

Ventilation Assessment

On June 28, 2016, we conducted visual and physical assessments of all ventilation 

components at the facility. Physical measurements of the facility were taken with a Model 

DISTO E7100i laser-tape measure (Leica Geosystems AG, Heerbrugg, Switzerland). 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 VelociCalc Plus 

Model 8324 Rotating Vane Anemometer (TSI Incorporated, Shoreview, MN). Differential 
Health Hazard Evaluation Report 2015-0163-3298 Page 11

pressure measurements between adjacent spaces were taken under various ventilation 

scenarios using a DG-500 Pressure Gauge (Energy Conservatory, Minneapolis, MN). 

NIOSH Medical Survey

Participants

We invited all current employees and the owner to participate in the medical survey at the 

workplace during June 29–30, 2016. Participation was voluntary and written informed 

consent was obtained from each participant before testing. The survey included, in the order 

performed, a medical and work history questionnaire, quantification of exhaled nitric oxide, 

impulse oscillometry, spirometry, and if indicated the administration of bronchodilator 

with repeat impulse oscillometry and spirometry. We mailed participants their individual 

reports explaining their breathing test results and recommended each participant provide the 

information to their personal physician.

Questionnaire

We used an interviewer-administered computerized questionnaire to ascertain symptoms 

and diagnoses, work history at this coffee processing facility and other coffee or flavoring 

companies, and cigarette smoking history. Questions on respiratory health were derived 

from five standardized questionnaires, the European Community Respiratory Health Survey 

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

questionnaire (ATS-DLD-78) [Ferris 1978], the International Union Against Tuberculosis 

and Lung Disease [Burney et al. 1987, 1994], and the Third National Health and Nutrition 

Examination Survey (NHANES III) [CDC 1996] and NHANES 2007–2012 questionnaires 

[CDC 2017a]. Some of the questions appeared on more than one of the standardized 

questionnaires. We also supplemented our questionnaire with additional respiratory and 

systemic symptom questions. 

Spirometry

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

the lungs. Test results were compared with expected normal values. The test included three 

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

participant can forcefully blow out after taking a deep breath), 2) FEV1 (the amount of air 

that the participant can blow out in the first second of exhaling), and 3) the ratio of FEV1 to 

FVC. We used American Thoracic Society 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]. 
Page 12 Health Hazard Evaluation Report 2015-0163-3298

Impulse Oscillometry

Many occupational lung diseases (e.g., chronic obstructive pulmonary disease (COPD), 

asthma) involve the small airways; however, this part of the lung is difficult to evaluate noninvasively. Oscillometry is a helpful technology to understand the effects of occupational 

exposures on the small airways. There are no contraindications to the test as this test is 

conducted using regular breathing and does not require a forceful exhalation [Smith et al. 

2005]. Spirometry can be normal despite respiratory symptoms or evidence of small airways 

disease on lung biopsy [King et al. 2011; Oppenheimer et al. 2007]; therefore, oscillometry 

results complement spirometry and can be used when spirometry is not possible because of a 

contraindication.

We used an impulse oscillometry machine (CareFusion Corp., San Diego, CA) to measure 

resistance (R), the energy required to propagate the pressure wave through the airways, 

and reactance (X), which reflects the viscoelastic properties of the respiratory system. The 

impulse oscillometry testing machine sends sound waves called pressure oscillations at 

different frequencies (e.g., 5 Hertz and 20 Hertz) into the airways to measure how airways 

respond to these small pressures. The test calculates 1) the airway resistance at different 

frequencies including 5 Hertz (R5) and 20 Hertz (R20), and the difference between R5 

and R20 (DR5-R20); 2) the reactance at different frequencies including 5 Hertz (X5); 3) 

resonance frequency (Fres) which is the frequency where there is no airway reactance; and 

4) the total reactance (AX) at all frequencies between 5 Hertz and the Fres. The predicted 

values for R and X were based on sex and age according to reference values recommended 

by the manufacturer [Vogel and Smidt 1994]. R5 was considered abnormal (elevated) if 

the measured value was equal to or greater than 140 percent of the predicted R5. X5 was 

considered abnormal (decreased) if the value of the predicted X5 minus measured X5 was 

equal to or greater than 0.15 kilopascals per liter per second (kPa/(L/s)). DR5-R20 values 

greater than 30% were considered abnormal and evidence of frequency dependence [Smith 

2015]. We interpreted the test as normal if both the R5 and X5 were normal [Smith 2015]. 

We defined possible large (central) airways abnormality as a normal X5 and elevated R5 

with no evidence of frequency dependence. We defined a possible small airways abnormality 

if there was evidence of frequency dependence and/or a decreased X5 with or without an 

elevated R5. We defined possible combined small (peripheral) and large (central airways) 

abnormality as a decreased X5 and elevated R5 with no evidence of frequency dependence. 

Bronchodilator Reversibility Testing for Impulse Oscillometry and Spirometry

If a participant had abnormal impulse oscillometry or spirometry, we repeated both tests after 

the participant received a bronchodilator inhaler medication (i.e., albuterol), which can open 

the airways in some individuals (e.g., asthmatics). For oscillometry, we defined reversibility 

(improvement) after bronchodilator administration as a decrease of at least 20% of either Fres 

or R5 or a decrease of 40% for AX. For spirometry, we defined reversibility (improvement) 

as increases of at least 12% and 200 mL for either FEV1 or FVC after bronchodilator 

administration. 

Fractional Exhaled Nitric Oxide (FeNO) 

We used the NIOX MINO® device (Aerocrine Inc., Morrisville, NC) to measure the amount 
Health Hazard Evaluation Report 2015-0163-3298 Page 13

of nitric oxide in the air the participant breathed out. Nitric oxide is a gas produced by the 

airways, and elevated levels can be a sign of eosinophilic airway inflammation in asthma 

[Dweik et al. 2011]. In adults, fractional nitric oxide concentration in exhaled breath levels 

above 50 ppb are considered elevated. In adults with asthma, elevated levels might indicate 

their asthma is uncontrolled [Dweik et al. 2011].

Statistical Analysis

Industrial Hygiene Survey and Ventilation Assessment

We performed analyses using Excel (Microsoft®, Redmond, WA) and SAS version 9.3 (SAS 

Institute, Cary, NC). We created summary statistics by work area, 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

We calculated frequencies and standardized morbidity ratios (SMRs) using SAS version 9.3 

(Cary, NC). The SMRs compare prevalences of symptoms and spirometric abnormalities 

among participants with expected prevalences of a sample of the general population reflected 

in the NHANES III (1988–1994, symptom and spirometry data), NHANES 2007–2012 

(symptom data), and NHANES 2007–2010 (spirometry data) adjusting for gender, race/

ethnicity, age (less than 40 years old or 40 years or greater), and cigarette smoking categories 

(ever/never). For comparisons with the U.S. population, we used the most recent NHANES 

survey available for the specific comparisons.

Results

All results tables are located in Appendix A.

Industrial Hygiene Survey 

Personal and Area Full-shift Air Sampling Results 

Personal and area full-shift TWA air concentrations measured using OSHA Methods 

1013/1016 can be seen in Table A1. We collected 10 personal and 18 area full-shift TWA air 

samples. Seven of the personal air samples were above the NIOSH REL of 5 ppb diacetyl, 

and five were above the NIOSH REL of 9.3 ppb 2,3-pentanedione. The highest full-shift 

personal samples for diacetyl (18.8 ppb) and 2,3-pentanedione (18.7 ppb) were collected on 

employees with multiple tasks and duties in the production area. Employees with personal 

air samples above the NIOSH REL for diacetyl and 2,3-pentanedione performed roasting, 

grinding, or packaging. 

Twelve area full-shift air samples were above the NIOSH REL for diacetyl. Because area air 

samples are not personal air samples collected directly on an employee, the NIOSH RELs 

are not directly applicable to the results for exposure monitoring purposes. However, area air 

samples can highlight areas with higher exposure risk, and the RELs can be used as points 

of reference. The following areas had full-shift air levels that exceeded the NIOSH REL for 

diacetyl: Diedrich roaster (5.1 ppb–11.8 ppb), grinder (8.1 ppb–9.6 ppb), auto-fill packaging 
Page 14 Health Hazard Evaluation Report 2015-0163-3298

machine (8.1 ppb–15.2 ppb), packaging/storage (6.2 ppb–15.0 ppb), and the green bean 

silo area (5.8 ppb–10.8 ppb). The following areas had full-shift air levels that exceeded the 

NIOSH REL for 2,3-pentanedione: Diedrich roaster (4.8 ppb–11.2 ppb), packaging/storage 

(5.8 ppb–15.3 ppb), and the green bean silo area (5.1 ppb–10.6 ppb). 

Task-based Air Sampling Results

Personal task-based air concentrations can be seen in Tables A2 and A3. We collected 25 

personal task-based air samples using OSHA Methods 1013/1016 (Table A2). Task duration 

ranged from two minutes to 22 minutes with a median of 16 minutes. We collected personal 

task air samples while employees roasted coffee (n = 9), ground coffee (n = 8), and packaged 

coffee (n = 8). We measured the highest exposures to diacetyl (range: 29.8 ppb–68.9 ppb) 

while employees ground coffee. We collected two 15-minute samples (29.8 ppb, 33.1 ppb) 

while employees ground coffee; they both exceeded the NIOSH STEL of 25 ppb for diacetyl. 

Diacetyl exposures measured while employees packaged coffee ranged from 5.8 ppb to 18 

ppb; we collected two 15-minute samples (12.7 ppb, 14.2 ppb), and they did not exceed 

the NIOSH STEL for diacetyl. Task-based air samples during coffee roasting ranged from 

2.2 ppb to 9.5 ppb for diacetyl; we collected one 15-minute sample (3.4 ppb), and it did not 

exceed the NIOSH STEL for diacetyl.

Task exposures to 2,3-pentanedione were similar to the diacetyl exposures described 

above. We measured the highest exposures to 2,3-pentanedione (range: 29.6 ppb–84.0 

ppb) while employees ground coffee. One of the two 15-minute samples (29.6 ppb, 33.3 

ppb) we collected on employees grinding coffee exceeded the NIOSH STEL of 31 ppb for 

2,3-pentanedione. 2,3-Pentanedione exposures measured while employees packaged coffee 

ranged from 6.7 ppb to 15.7 ppb; we collected two 15-minute samples (12.9 ppb, 14.6 ppb), 

and they did not exceed the NIOSH STEL for 2,3-pentanedinoe. Task exposures during 

coffee roasting ranged from 2.6 ppb to 10.1 ppb for 2,3-pentanedione. We collected one 

15-minute sample (3.5 ppb), and it did not exceed the NIOSH STEL for 2,3-pentanedione.

We collected 18 personal samples near the breathing zone of an employee using 

instantaneous canisters (Table A3). We measured the highest personal instantaneous samples 

while employees ground coffee (range: diacetyl, 30.8 ppb–50.4 ppb; 2,3-pentanedione, 28.6 

ppb–46.6 ppb). Instantaneous personal samples collected while employees used the auto-fill 

packaging machine ranged from 16.9 ppb to 21.5 ppb for diacetyl and 14.1 ppb to 22.1 ppb 

for 2,3-pentanedione. Instantaneous diacetyl and 2,3-pentanedione concentrations measured 

at the breathing zone of employees while they pulled a sample of beans from the roaster to 

check the quality of the roasted beans ranged from 11.5 ppb to 21.4 ppb for diacetyl and 

10.3 ppb to 17.7 ppb for 2,3-pentanedione. Instantaneous samples collected while employees 

dumped beans from the roaster’s cooling bin into plastic storage bins had concentrations 

ranging from 8.0 ppb to 22.6 ppb for diacetyl and 5.5 ppb to 15.8 ppb for 2,3-pentanedione. 

Samples collected while an employee vacuumed chaff from the roaster exhaust ranged from 

13.3 ppb to 14.5 ppb for diacetyl and 11.8 ppb to 13.6 ppb for 2,3-pentanedione.

Source Air Sampling Results

Instantaneous evacuated canister concentrations for diacetyl and 2,3-pentanedione can be 
Health Hazard Evaluation Report 2015-0163-3298 Page 15

seen in Table A4. Instantaneous samples were less than 30 seconds in duration. We collected 

three instantaneous source samples using evacuated canisters. Diacetyl and 2,3-pentanedione 

concentrations near the transfer point of the auto-fill machine during packaging of 12 oz 

or 5-pound bags ranged from 5.5 ppb to 9.1 ppb for diacetyl and 4.5 ppb to 7.0 ppb for 

2,3-pentanedione.

Beginning and End of Day Air Sampling

We collected instantaneous samples using evacuated canisters at the beginning of the 

production shifts on June 27 and 28, 2016, and the end of production on June 28, 2016. 

All three samples were taken in the center of the production floor. The beginning of day 

diacetyl air concentration was 11.3 ppb on June 27, 2016, and 5.7 ppb on June 28, 2016, and 

the 2,3-pentanedione air concentration was 9.8 ppb on June 27, 2016, and 3.2 ppb on June 

28, 2016. The end of day diacetyl air concentration on June 28, 2016, was 11.1 ppb and the 

2,3-pentanedione air concentration was 9.7 ppb.

Bulk Samples and Headspace Results

Headspace results of diacetyl and 2,3-pentanedione for the bulk samples of roasted coffee 

beans can be seen in Table A5. The highest air concentration of diacetyl (3,434 ppb) and 

2,3-pentanedeione (4,145 ppb) was observed in the headspace of a decaffeinated roast. All 

headspace results for 2,3-hexanedione for the bulk samples of roasted coffee were below the 

LOD.

Real-time Monitoring: Carbon Dioxide (CO2), Carbon Monoxide (CO), and Total Volatile 

Organic Compounds (VOCs)

A summary of the real-time CO, CO2, temperature, relative humidity, and total VOC area 

monitoring results can be seen in Table A6. Overall, levels of CO2 and CO were consistent 

between the two days of our survey. At the roaster, we measured 295 ppm to 957 ppm for 

CO2 and <0.1 ppm to 4.2 ppm for CO. At the grinder, we measured 194 ppm to 1,259 ppm 

for CO2 and <0.1 ppm to 90.2 ppm for CO. We measured peak levels of CO2 (maximum 

of 1,259 ppm) and CO (maximum of 90.2 ppm) at the grinder when an employee ground 

5-pound bags of roasted coffee. Total VOC measurements at the grinder ranged from 31 ppm 

to 13,012 ppm, with an average of 484 ppm across the two days of our survey.

A summary of continuous, personal measurements of CO can be seen in Table A7. TWA 

personal CO measurements ranged from <1 ppm to 3.7 ppm and were below the NIOSH 

REL of 35 ppm for CO exposure. We observed the highest CO levels (maximum 63 ppm) on 

production employees while they ground 5-pound bags of roasted coffee. 

Personal Exhaled Carbon Monoxide (CO) Measurements

Seven employees that participated in the personal air sampling also provided breath samples 

for measurement of CO by exhaling into a monitor at various times during the workday. 

Measurements were typically collected at the beginning of the shift, lunch break, and at 

the end of the shift. After exhaling into the monitor, the device reported a CO value in ppm 

and also calculated an estimated COHb percentage. The overall average CO level was 5.7 

ppm (range: 0 ppm–24 ppm) and the average COHb percentage was 1.5% (0–4.5%). The 
Page 16 Health Hazard Evaluation Report 2015-0163-3298

average CO level in smokers was 11.1 ppm (range: 3 ppm–24 ppm) and the average COHb 

percentage was 2.4% (range: 1.1%–4.5%). All COHb test results in non-smokers were below 

1.4% and in smokers were below 4.5%.

Ventilation Assessment Results

Two air-handling units (AHU’s) were in use on the days of our survey. One AHU supplied 

air to the office and café areas, and the second AHU supplied air to the production area. The 

production space was under negative pressure relative to the office and café areas when both 

AHU’s were on and when both AHU’s were off. An accessory fan placed near the grinder 

was operated whenever coffee was ground. An adequate supply of outdoor air, typically 

delivered through the heating, ventilation, and air-condition system, is necessary in any 

occupied spaces to dilute pollutants that are released by equipment, processes, products, 

and people. We were unable to accurately measure the amount of fresh, outdoor air being 

provided by the AHU to the production area. The outdoor air supply may be sufficient, at 

least during certain parts of the year. If the amount of outdoor air supplied to the space is low, 

however, increasing the outdoor air flow will provide more dilution and removal of airborne 

contaminants from the space. Consistently supplying the production space with appropriate 

outdoor air may not bring all personal exposures to diacetyl and 2,3-pentanedoine below the 

NIOSH RELs, but it is an inexpensive, easy place to start engineering control improvements. 

Providing more outdoor air flow will enhance dilution and removal of contaminants, but 

there will be additional energy costs associated with heating and cooling that outside air 

for much of the year. Those decisions should be made as part of an overall plan to improve 

engineering controls at the facility. A ventilation system expert can help meet all ventilation 

requirements in the production space and other areas of the building occupied by employees.

Medical Survey 

Demographics

Fifteen (79%) of 19 onsite employees present during June 29–30, 2016, participated in the 

medical survey, including all production employees. Six (40%) participants were male, 14 

(93%) were white, and the median age was 32 years (range: 23–55 years). Median tenure 

at the facility was 1.3 years (range: 0–7.0 years). Six participants had previously worked 

at other coffee production facilities; among these, median tenure in the coffee industry was 

2.9 years (range: 0–10.5 years). Eight (53%) participants were current smokers or former 

smokers.

All 15 participants reported spending time in the production area of the facility during the 

work week. Of the 15 participants, 14 reported being within an arm’s length of the roaster 

while it was operating and the cooling bins that contain roasted coffee beans that were 

cooling. All participants reported being within an arm’s length of the production grinder 

while it was operating. 

Symptoms and Self-Reported Diagnoses

The prevalences of symptoms over both the last 12 months and four weeks reported at 

the time of the survey are listed in Table A8. Mucous membrane symptoms were the most 

commonly reported symptoms over the past 12 months, specifically nose symptoms (n=12, 
Health Hazard Evaluation Report 2015-0163-3298 Page 17

80%) and eye symptoms (n=7, 47%). Some production employees noted these symptoms 

were caused or aggravated by green coffee bean dust, cleaning the roasting machine, and 

packaging roasted beans. Three participants reported their mucous membrane symptoms 

were better when away from work. 

Five (33%) participants reported one or more lower respiratory symptoms in the past 12 

months: cough, awoke with chest tightness, awoke with shortness of breath, chest wheezing 

or whistling, asthma attack, breathing trouble, or shortness of breath on level ground or 

walking up a slight hill. One of these five participants reported lower respiratory symptoms 

in the 4 weeks before the medical survey. Two employees reported their lower respiratory 

symptoms were aggravated by work or better when away from work. 

Two participants reported a history of nasal allergies, two eczema, one asthma, and one 

gastroesophageal reflux disease. All these conditions were diagnosed before employment 

at the coffee processing facility. No participants reported a diagnosis of chronic bronchitis, 

bronchiolitis obliterans, interstitial lung disease, hypersensitivity pneumonitis, chemical 

pneumonitis, sarcoidosis, heart disease, or vocal cord dysfunction. 

Medical Tests

One spirometry test was interpreted as having a mild restrictive pattern with no significant 

improvement after bronchodilator. Two oscillometry tests were interpreted as consistent 

with a large airway abnormality, and one was interpreted as consistent with a small airway 

abnormality. Three exhaled nitric oxide tests were interpreted as elevated. One half of 

participants with abnormalities on medical tests were current or former smokers. Two 

participants with abnormalities on medical tests reported lower respiratory symptoms, such 

as wheezing, that did not improve away from work. 

NHANES Comparison of Symptoms, Diagnoses, and Spirometry

The SMR for wheezing was elevated at 2.4 (Table A9). The SMRs for cough, phlegm, sinus 

problems, eye symptoms, and physician-diagnosed asthma were not elevated. In addition, no 

excess of restrictive spirometry abnormalities were present compared with the general U.S. 

population, adjusted for age distribution, race/ethnicity, sex, and smoking history.

Discussion

At the coffee roasting and packaging facility that is the subject of this report, the highest 

area samples for diacetyl and 2,3-pentanedione were observed in areas where coffee was 

ground (near the grinder). Diacetyl, 2,3-pentanedione, 2,3-hexanedione, other VOCs, and 

other compounds such as CO2 and CO are naturally produced when coffee beans are roasted, 

and grinding the 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 2016]. 
Page 18 Health Hazard Evaluation Report 2015-0163-3298

Alpha-Diketones 

Personal Air Sampling 

All personal air samples with concentrations above the NIOSH RELs for diacetyl or 

2,3-pentanedione were collected on employees with primary job duties on the production 

floor. The highest personal full-shift samples were collected on employees with grinding and/

or packaging duties. The personal full-shift air sample collected on an employee with primary 

duties in the office area was below the NIOSH REL for diacetyl and 2,3-pentanedione. 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 (Table 5-27) [NIOSH 2016], after a 45-year working lifetime exposure 

to 10 ppb (a concentration somewhat lower than the highest concentration measured at this 

facility), NIOSH estimated less than 2 in 1,000 workers would develop reduced lung function 

(FEV1 below the 5th percentile). NIOSH predicted that around 2 in 10,000 workers exposed 

to diacetyl at 10 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 20 ppb (a concentration slightly 

higher than the highest concentration measured at this facility), NIOSH estimated that 3 in 

1,000 workers would develop reduced lung function (FEV1 below the 5th percentile). NIOSH 

predicted that 5 in 10,000 workers exposed to diacetyl at 20 ppb would develop more severe 

lung function reduction. The effects of a working lifetime exposure at 19 ppb would be close 

to 20 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. 

Area Air Sampling 

Areas near the Diedrich roaster, green bean silo storage (located near the roaster), grinder, 

and the packaging and storage areas had air levels that exceeded the NIOSH REL for diacetyl 

or 2,3-pentanedione. Elevated levels of diacetyl and 2,3-pentanedione measured near the 

green bean silo storage were likely caused by the close proximity to nearby sources of alpha 

diketones to include roasted whole beans and ground coffee in the roasting, packaging and 

storage, and grinding areas. We note that NIOSH RELs are intended to be directly compared 

with personal measurements; therefore, an area air sample that exceeds a NIOSH REL is only 

an indication of potential personal exposures. 

Task-Based Exposures

Coffee processing involves multiple tasks that can cause intermittent exposure to diacetyl and 

2,3-pentanedione. Traditional full-shift sampling will not characterize these intermittent, peak 

exposures. The purpose of task-based sampling was to understand what tasks have higher 

exposures to diacetyl and 2,3-pentanedione. Short-term peak exposures might have effects on 

the lungs even when full-shift average exposures are relatively low, as has been observed in 

the microwave popcorn industry [Kanwal et al. 2006]. 

Our task-based air sampling revealed some tasks had higher air concentrations of diacetyl 

or 2,3-pentanedione than other tasks. The highest exposure to diacetyl (68.9 ppb) and 

2,3-pentanedione (84.0 ppb) were measured while an employee was grinding coffee (Table 
Health Hazard Evaluation Report 2015-0163-3298 Page 19

A2). The greater surface area for off-gassing that is produced during grinding could have 

resulted in the higher air concentrations [Akiyama et al. 2003]. All 15-minute samples 

collected while employees ground coffee exceeded the NIOSH STEL for diacetyl. One of the 

15-minute air samples collected while an employee ground coffee was also above the NIOSH 

STEL for 2,3-pentanedione. No 15-minute samples collected during packaging or roasting 

tasks exceeded the NIOSH RELs for diacetyl or 2,3-pentanedione. The roaster operator often 

remained near the roaster control panels, directly adjacent to the roaster cooling bin. The 

downdraft system on the roaster machine pulled air over the roasted beans and down into the 

cooling drum to accelerate cooling, and this engineering control likely helped mitigate the 

roaster operator’s exposure.

Instantaneous Sampling

We measured diacetyl and 2,3-pentanedione using instantaneous sampling in which 

sample duration was less than 30 seconds. These instantaneous samples were collected to 

identify and describe tasks and point sources of diacetyl and 2,3-pentanedione. The highest 

instantaneous concentrations for diacetyl and 2,3-pentanedione were taken at the breathing 

zone of an employee while the employee ground roasted beans for 5-pound bags. The second 

highest breathing zone instantaneous concentrations for diacetyl and 2,3-pentanedione 

were observed while an employee was hand-blending six pounds of roasted coffee. The 

instantaneous breathing zone sampling results for dumping roasted beans from the roaster 

into the cooling bin were among the lowest we measured during the site visit. Instantaneous 

source samples taken at the transfer point from the packaging machines were also relatively 

low. Overall, the instantaneous sampling results suggest the major task and point source of 

diacetyl and 2,3-pentanedione at this facility is the grinder while grinding coffee beans.

2,3-Hexanedione is another alpha-diketone produced naturally during the coffee roasting 

process and used in the food industry, although to a lesser extent than diacetyl and 

2,3-pentanedione. The respiratory toxicity of 2,3-hexanedione appears to be lower than 

diacetyl and 2,3-pentanedione, although it is likely not free of toxicity [Morgan et al. 

2016]. Across all sample types, results for 2,3-hexanedione were low. The highest levels of 

2,3-hexanedione (maximum 1.3 ppb) were obtained in the instantaneous samples that also 

had the highest levels of diacetyl and 2,3-pentanedione (grinding roasted coffee beans).

Our instantaneous samples collected at the beginning of the day on June 27 and 28, 2016, and 

at the end of production on June 28, 2016, indicated that background levels of diacetyl can 

remain elevated even when production activities have ceased overnight. Both samples were 

taken in the center of the production floor. The beginning of day diacetyl air concentration 

on June 27, 2016, was 11.3 ppb on June 27, 2016, and 5.7 ppb on June 28, 2016, and the 

2,3-pentanedione air concentration was 9.8 ppb on June 27, 2016, and 3.2 ppb on June 28, 

2016. The end of day diacetyl air concentration on June 28, 2016, was 11.1 ppb, and the 

2,3-pentanedione air concentration was 9.7 ppb. Whole or ground coffee that is off gassing 

from bags stored in the finished product storage area combined with elevated air levels of 

alpha diketones from the production activities like grinding and packaging ground coffee 

without sufficient ventilation to remove alpha diketones might have contributed to the 

elevated levels of diacetyl even after production activities have ceased.
Page 20 Health Hazard Evaluation Report 2015-0163-3298

Bulk samples

Diacetyl is not found in green coffee beans. Rather, diacetyl is generated later in the coffee 

roasting process [Daglia et al. 2007]. As expected, we found that roasted coffee emits alphadiketones into the headspace of sealed vessels, indicating that roasted coffee is a considerable 

source of alpha-diketones in the facility. The amount of time beans were roasted, and the 

amount of time roasted beans off-gassed before the collection of bulk samples could be 

responsible for differences in headspace analysis results. 

Real-time Sampling for CO, CO2, and VOCs

Our real-time monitoring found the highest overall levels of total CO, CO2, and VOCs were 

observed at the main grinders when employees were using the coffee grinders. Our realtime monitoring for total VOCs, although not specific for diacetyl or 2,3-pentanedione, 

highlighted sharp increases in releases of VOCs during the grinding of roasted coffee beans. 

Measurement of total VOCs included numerous alpha-diketones and many other volatile 

compounds. The individual levels of each compound included in a total VOC measurement 

can vary widely [Rhoades 1960; Akiyama 2003, Shibamoto 2015]. We measured the highest 

levels of total VOCs (13,012 ppb) during the grinding of whole beans for 5-pound bags of 

coffee. Relocation of the grinder to a dedicated workspace with increased ventilation would 

help reduce VOC concentrations during these tasks.

Overall, average levels of CO2 and CO were consistent between the two days of our survey 

and were all well below ceiling limits. We measured levels of CO2 and CO at the roaster that 

ranged from 295 ppm to 957 ppm for CO2 and <0.1 ppm to 4.2 ppm for CO. Levels at the 

grinder ranged from 194 ppm to 1,259 ppm for CO2 and <0.1 ppm to 90.2 ppm for CO. We 

measured peak levels of CO2 (maximum of 1,259 ppm) and CO (maximum of 90.2 ppm) at 

the grinder when an employee ground 5-pound bags of roasted coffee. Average and maximum 

levels of CO2 and CO were higher on the first day of the survey. We observed more grinding 

on the first day of our survey.

None of the average area levels of CO exceeded the NIOSH REL (35 ppm) or OSHA PEL 

(50 ppm). The highest personal CO levels were observed on production employees while 

grinding 5-pound bags of roasted coffee. Levels of CO near an employee’s breathing zone 

were as high as 63 ppm and while an employee was grinding 5-pound bags of coffee. 

One limitation of interpreting real-time measurements for VOCs, CO2, or CO, is the results 

can only be summarized within the context of when tasks were documented. Increases 

in VOCs, CO2, or CO might be explained by another task that occurred but not captured 

in our notes. For example, activity at the nearby grinders might have contributed to the 

elevated measurements of diacetyl and 2,3-pentanedione for workers performing tasks in the 

packaging area.

Ventilation

We commend the management on the current configuration of the ventilation system that 

separates the production room air from the office, café, and breakroom areas. One AHU 

supplied air to the office, café, and breakroom areas, and the second AHU supplied air 

to the production area. The production space was under negative pressure, relative to the 

office and café areas, when both AHU’s were on and when both AHU’s were off. This 
Health Hazard Evaluation Report 2015-0163-3298 Page 21

configuration likely contributed to the low personal and area air concentrations of diacetyl 

and 2,3-pentanedione in the café, breakroom, and office areas.

Medical Survey 

Overall, mucous membrane symptoms, specifically eye and nose symptoms, were the most 

commonly reported symptoms. Some employees reported their mucous membrane symptoms 

were caused or aggravated by green coffee dust, cleaning the roaster, or packaging roasted 

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

used to transport coffee) are known risk factors for work-related asthma [Figley and Rawling 

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

sensitized to coffee dust can react to low concentrations in the air. Others can experience 

irritant-type symptoms from exposure to coffee dust [Oldenburg et al. 2009].

Upper respiratory disease such as allergic rhinitis (hay fever, nasal allergies) and sinusitis 

are sometimes associated with lower respiratory symptoms and asthma, and can 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. All five participants that 

reported lower respiratory symptoms also reported nasal or sinus problems or physiciandiagnosed hay fever or nasal allergies. Three production workers who reported lower 

respiratory symptoms also noted that green coffee beans or packaging roasted coffee 

aggravated their nose or sinuses. 

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]. One way to prevent 

symptoms related to green coffee dust and chaff might be to make N-95 disposable filteringface piece respirators available for voluntary use when emptying burlap bags of green beans 

into the storage silos or when emptying the chaff containers or cleaning the green bean 

storage area.

The number of participants with physician-diagnosed asthma was not different from that 

observed in the U.S. population. However, 33% (n=5) of participants reported lower 

respiratory symptoms. Two of these participants reported their lower respiratory symptoms 

were work-related. 

Asthma symptoms often improve when away from exposures that trigger symptoms while 

other lung diseases such as obliterative bronchiolitis or COPD generally do not improve. 

Spirometry can be used to help detect and follow individuals with asthma and other lung 

diseases such as obliterative bronchiolitis or COPD. Spirometry can show if air is exhaled 

from the lungs more slowly than normal (i.e. obstructive abnormality) or if the amount of air 

exhaled is smaller than normal (i.e., restrictive abnormality). In asthma, intermittent airways 

obstruction occurs that is reversible after treatment with bronchodilator medications (e.g., 

albuterol). In obliterative bronchiolitis, scar tissue prevents the small airways (bronchioles) 

from opening up when albuterol is given. In other words, the airways are fixed and not 

responsive (reversible) to bronchodilator medicine. The obstructed airways prevent rapid 

emptying of the lung air sacs (alveoli) during exhalation. This explains why the respiratory 
Page 22 Health Hazard Evaluation Report 2015-0163-3298

symptoms of those with occupational obliterative bronchiolitis do not tend to improve 

when away from work-related exposures; however, avoidance of further exposure can stop 

progression of the disease [Akpinar-Elci et al 2004]. 

Spirometry and impulse oscillometry measure different things. Spirometry assesses 

airflow and is the breathing test typically used to screen for flavoring-related lung disease. 

Impulse oscillometry accesses the airways response to a sound or pressure wave and has 

not commonly been used to screen for flavoring-related lung disease. In general, during 

the impulse oscillometry test, a small pressure impulse (sound wave) is imposed upon the 

inspiratory and expiratory airflow during normal tidal breathing. This pressure wave causes 

a disturbance in the airflow and pressure, and the response of the airways (i.e., change in 

pressure to change in flow) is a measure of the resistance to airflow in the airways [Desiraju 

and Agrawal 2016]. Impulse oscillometry might be useful as an indirect measure of airflow 

obstruction and helpful in persons not able to perform forced breathing maneuvers required 

during the spirometry test. The impulse oscillometry test has been used for many years to 

measure changes in the airways of children with lung problems such as asthma and cystic 

fibrosis [Song et al. 2008; Komarow et al. 2011; Shi et al. 2012; Schulze et al. 2016]. More 

recently, impulse oscillometry has been used to investigate lung problems in adults exposed 

to dust or chemicals, such as World Trade Center emergency responders and soldiers 

returning from deployment overseas [Oppenheimer et al. 2007; Berger et al. 2013; Weinstein 

et al. 2016]. Over the years, researchers have developed reference (predictive) equations for 

different populations of children for oscillometry [Malmberg et al. 2002; Park et al. 2011; Lee 

et al. 2012; de Assumpção et al. 2016]. For adults, fewer reference equations are available 

for oscillometry [Vogel and Smidt 1994; Newbury et al. 2008; Schulz et al. 2013]. The 

predicted values we used for oscillometry measures were based on gender and age according 

to references values recommended by the manufacturer. Unlike predictive equations used for 

spirometry, the impulse oscillometry reference equations we used did not take into account 

height, race, or smoking status [Vogel and Smidt 1994].

Our findings of upper and lower respiratory symptoms with a work-related pattern in some 

employees, over two-fold excess of wheeze, and abnormalities on lung function testing in 

about a 40% of participants suggest a burden of respiratory problems in this workforce. 

The upper respiratory symptoms that improve away from work are likely related to 

workplace exposures. However, the lower respiratory symptoms such as wheeze did not 

have a work-related pattern. These lower respiratory symptoms and the lung function 

abnormalities we found are not specific to a particular respiratory problem or disease. 

They could be related to workplace exposures or to other factors. Indeed, some employees 

had respiratory diagnoses that preceded employment at this facility. Because of the small 

number of participants and the need to protect individual employee privacy, we cannot 

provide more detailed results that might shed light on possible work-relatedness, such 

as health measures by job title or task. We mailed each participant their individual lung 

function test results with an explanation of the results and recommended each participant 

provide the information to their personal physician.

We recommend starting a medical monitoring program because air sampling found 

concentrations of diacetyl and 2,3-pentanedione above the NIOSH RELs and nine employees 
Health Hazard Evaluation Report 2015-0163-3298 Page 23

had abnormal breathing tests or history of lower respiratory symptoms. All production 

employees and any employees that assist with production tasks (e.g., roasting, interacting 

with open storage bins/containers of roasted coffee, grinding, weighing, or packaging coffee) 

should participate in the workplace medical monitoring program. A medical monitoring 

program is a means of early identification of employees who might be developing lung 

disease (e.g., asthma, obliterative bronchiolitis) and can help prioritize interventions to 

prevent occupational lung disease. The NIOSH medical survey results can serve as a baseline 

for employees who participated. In a workplace with risk of occupational lung disease, 

prevention of smoking-related lung disease is important and makes the detection of workrelated adverse effects easier. The Centers for Disease Control and Prevention offers tools and 

resources for setting up a smoking cessation program [CDC 2017b].

Conclusions

We identified specific work tasks resulting in air concentrations of diacetyl that exceeded 

the NIOSH REL and STEL for diacetyl and the REL for 2,3-pentanedione. Seven of the 

nine personal full-shift air concentrations collected on employees in the production area 

were above the NIOSH REL of 5 ppb for diacetyl, and five of nine personal full-shift air 

concentrations measured on employees in the production area were above the NIOSH 

REL of 9.3 ppb for 2,3-pentanedione. Overall, the highest employee exposures to diacetyl, 

2,3-pentanedione, and CO were measured while employees ground roasted coffee beans. 

Likewise, the highest area samples for total VOCs, CO, diacetyl, and 2,3-pentanedione were 

observed near the grinder when an employee was grinding coffee. All production floor areas 

had full-shift concentrations of diacetyl that exceeded the NIOSH REL of 5 ppb for diacetyl 

and 9.3 ppb for 2,3-pentanedione. In contrast, personal and area levels of diacetyl and 

2,3-pentanedione in the café, breakroom, and office areas were consistently low and below 

the NIOSH RELs for diacetyl and 2,3-pentanedione.

Recommendations 

On the basis of our findings, we recommend the actions listed below. 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.

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. Consult with a ventilation engineer to install local exhaust ventilation at the grinders. 

2. Consider relocating the grinders to an area with little or no bystander foot traffic to 

minimize potential exposure risks to employees not directly using the grinder.
Page 24 Health Hazard Evaluation Report 2015-0163-3298

3. Consult with a ventilation engineer to increase the local exhaust ventilation in the 

downdraft table at the roaster.

4. Consult with a ventilation engineer to install local exhaust ventilation at the auto-fill 

packaging machine.

5. After engineering controls have been installed at the grinder, roaster, and auto-fill 

packaging machine, conduct personal air monitoring for diacetyl and 2,3-pentanedione 

on all employees with primary duties in the production area using OSHA Sampling 

Method 1012 for diacetyl [OSHA 2008] and OSHA Sampling Method 1016 for 

2,3-pentanedione [OSHA 2010]. Because air levels of VOCs like diacetyl and 

2,3-pentanedione can fluctuate based on production schedules, we recommend 

personal air sampling for diacetyl and 2,3-pentanedione over multiple days. 

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. Whenever possible, employees should avoid spending time in the immediate area 

where coffee is being ground or ground coffee is being packaged.

2. Continue to cover bins of roasted beans to aid in reducing the overall emission of 

alpha-diketones and other chemicals (e.g., CO, CO2) into the workplace.

3. Continue to periodically clean the roaster’s exhaust according to manufacturer 

instructions to remove chaff build up to reduce a fire hazard and to improve the 

efficiency, energy usage, and roaster performance.

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 

1910.1200] requires 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 hazardous respiratory exposures depends on avoiding breakdowns in 

implementation that result in insufficient protection. Proper use of respiratory protection 
Health Hazard Evaluation Report 2015-0163-3298 Page 25

(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. In addition to engineering and administrative controls, respiratory protection is a 

potential option to further reduce exposures to alpha-diketones (e.g., diacetyl and 

2,3-pentanedione). If follow-up air sampling after engineering controls have been 

installed indicates levels of diacetyl and 2,3-pentanedione above their respective 

NIOSH RELs and STELs, we recommend respiratory protection be used during 

tasks with elevated exposures. If respiratory protection is used, NIOSH-certified 

respirators should be fitted with organic vapor cartridges and particulate filters. The 

choice of respirator should be guided by personal exposure sampling for diacetyl and 

2,3-pentanedione (NIOSH 2004). 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 APF of 10, and air-purifying 

full-face respirators have an APF of 50. Also, there are powered-air purifying 

respirators that have APFs of 25, 50, or 1000. The OSHA APFs can be found in Table 

1 of OSHA Respiratory Protection Standard at https://www.osha.gov/pls/oshaweb/

owadisp.show_document?p_table=STANDARDS&p_id=12716.

 If mandatory respiratory protection is used, a written respiratory protection program 

should be implemented as required by the OSHA Respiratory Protection Standard (29 

CFR 1910.134), including training, fit testing, maintenance, and use requirements. 

2. Offer employees the voluntary use of N95 disposable filtering-facepiece respirators 

available for voluntary use for protection against green or roasted coffee dust exposure 

such as when 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 Standard (http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_

table=standards&p_id=9784). Information about Appendix D and voluntary use 

of respirators can be found on the OSHA website at https://www.osha.gov/video/

respiratory_protection/voluntaryuse_transcript.html.

 Please be aware that 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.

3. 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 in the 

production area. 
Page 26 Health Hazard Evaluation Report 2015-0163-3298

Medical Monitoring

The purpose of a medical monitoring 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. 

1. Institute a medical monitoring program for employees who work or assist in the 

production area. The medical monitoring should consist of evaluation with a 

questionnaire (to obtain health and work task information) and spirometry (to assess 

lung function) at baseline and at one year to monitor for respiratory symptoms and 

to establish employees’ baseline in lung function and any abnormal decline in lung 

function in the first year. Subsequently, an annual questionnaire evaluation should 

occur to monitor for respiratory symptoms. New or worsening respiratory symptoms 

should prompt additional evaluation including spirometry. Details about spirometry 

and a medical monitoring program can be found in chapter 9 of the NIOSH Criteria 

Document [NIOSH 2016].

2. If an employee is identified as likely having lung disease from exposure to diacetyl 

or 2,3-pentanedione, it should be viewed as a sentinel event indicating a breakdown 

in exposure controls occurred and potential risk for co-workers exists. Should this 

occur, the unanticipated source of exposure must 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 2016]. 

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 2017b].
Health Hazard Evaluation Report 2015-0163-3298 Page 27

Table A1. Time-weighted average OSHA Method 1013/1016 personal and area air sampling 

results by location, NIOSH survey, June 2016

Analyte Sample 

Type Location N

Above 

LOD

N (%)

Minimum

Concentration

(ppb)

Maximum

Concentration

(ppb)

Above 

REL

N 

Diacetyl Personal Office Area 1 1 (100%) 2.8 2.8 0

Diacetyl Personal Production Area 7 7 (100%) 4.2 18.8 6

Diacetyl Personal Roasting 2 2 (100%) 5.0 10.6 1*

Diacetyl Area Breakroom 1 1 (100%) 4.9 4.9 N/A

Diacetyl Area Café 4 4 (100%) 1.0 2.7 N/A

Diacetyl Area Grinding 2 2 (100%) 8.1 9.6 N/A

Diacetyl Area Office Area 1 1 (100%) 1.5 1.5 N/A

Diacetyl Area Packaging/Storage 4 4 (100%) 6.2 15.0 N/A

Diacetyl Area Auto-fill Packaging 

Machine 2 2 (100%) 8.1 15.2 N/A

Diacetyl Area Production Area, Green 

Bean Silo 2 2 (100%) 5.8 10.8 N/A

Diacetyl Area Roasting 2 2 (100%) 5.1 11.8 N/A

2,3-Pentanedione Personal Office Area 1 1 (100%) 2.9 2.9 0

2,3-Pentanedione Personal Production Area 7 7 (100%) 3.9 18.7 5

2,3-Pentanedione Personal Roasting 2 1 (100%) 4.3 10.1 1

2,3-Pentanedione Area Breakroom 1 1 (100%) 4.6 4.6 N/A

2,3-Pentanedione Area Café 4 4 (100%) 1.6 2.8 N/A

2,3-Pentanedione Area Grinding 2 2 (100%) 7.9 9.3 N/A

2,3-Pentanedione Area Office Area 1 1 (100%) 1.6 1.6 N/A

2,3-Pentanedione Area Packaging/Storage 4 6 (100%) 5.8 14.7 N/A

2,3-Pentanedione Area Auto-fill Packaging 

Machine 2 2 (100%) 7.5 15.2 N/A

Appendix A: Tables
Page 28 Health Hazard Evaluation Report 2015-0163-3298

Analyte Sample 

Type Location N

Above 

LOD

N (%)

Minimum

Concentration

(ppb)

Maximum

Concentration

(ppb)

Above 

REL

N 

2,3-Pentanedione Area Production Area, Green 

Bean Silo 2 2 (100%) 5.1 10.6 N/A

2,3-Pentanedione Area Roasting 2 2 (100%) 4.8 11.2 N/A

2,3-Hexanedione Personal Office Area 1 0 (0%) <0.2 <0.2 N/A

2,3-Hexanedione Personal Production Area 7 1 (13%) <0.2 0.5 N/A

2,3-Hexanedione Personal Roasting 2 0 (0%) <0.2 <0.2 

N/A

2,3-Hexanedione Personal Roasting 6 2 (33%) <0.2 0.4 N/A

2,3-Hexanedione Area Breakroom 1 0 (0%) <0.5 <0.5 N/A

2,3-Hexanedione Area Cafe 4 0 (0%) <0.5 <0.5 N/A

2,3-Hexanedione Area Grinding 2 2 (100%) 0.5 0.5 N/A

2,3-Hexanedione Area Office Area 1 0 (0%) <0.5 <0.5 N/A

2,3-Hexanedione Area Packaging/Storage 4 0 (0%) <0.5 <0.5 N/A

2,3-Hexanedione Area Auto-fill Packaging 

Machine 2 0 (0%) <0.5 <0.5 N/A

2,3-Hexanedione Area Production Area, Green 

Bean Silo 2 0 (0%) <0.5 <0.5 N/A

2,3-Hexanedione Area Roasting 2 0 (0%) <0.4 <0.5 N/A

Note: OSHA=Occupational Safety and Health Administration; NIOSH=National Institute for Occupational 

Safety and Health; N=number of samples; Above LOD(%)=number and percentage of samples above limit of 

detection (LOD); < indicates below the limit of detection; ≤ indicated less than or equal to the limit of detection; 

Above REL=number of samples 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; 

“Production Area” location includes employees cross-trained and performed tasks at different areas to include 

the green bean storage, packaging, and grinding areas. “−“indicates that there is currently no REL for 

2,3-hexanedione.

*We note that one of the samples collected on a roaster had a TWA of 4.99 ppb and the NIOSH REL is 5 ppb. 

Although this sample was not above the NIOSH REL, it approached the NIOSH REL.

Table A1 (cont.). Time-weighted average OSHA Method 1013/1016 personal and area air 

sampling results by location, NIOSH survey, June 2016
Health Hazard Evaluation Report 2015-0163-3298 Page 29

Table A2. Summary of OSHA Method 1013/1016 personal air sampling results by task, NIOSH 

survey, June 2016

Analyte Task N

Above LOD

N (%)

Minimum 

Concentration 

(ppb)

Maximum 

Concentration 

(ppb)

Mean (range) 

Sample Duration 

(minutes)

Diacetyl Grind coffee beans 8 8 (100%) 29.8 68.9 13 (2–18)

Diacetyl Package coffee 8 8 (100%) 5.8 18.0 13 (5–18)

Diacetyl Roast coffee beans 9 9 (100%) 2.2 9.5 18 (13–22)

2,3-Pentanedione Grind coffee beans 8 8 (100%) 29.6 84.0 13 (2–18)

2,3-Pentanedione Package coffee 8 8 (100%) 6.7 15.7 13 (5–18)

2,3-Pentanedione Roast coffee beans 9 9 (100%) 2.6 10.1 18 (13–22)

2,3-Hexanedione Grind coffee beans 8 1 (13%) <0.6 1.5 13 (2–18)

2,3-Hexanedione Package coffee 8 0 (0%) <0.6 <2.1 13 (5–18)

2,3-Hexanedione Roast coffee beans 9 0 (0%) <0.5 <0.8 18 (13–22)

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); < indicates below the LOD; ppb=parts per billion.
Page 30 Health Hazard Evaluation Report 2015-0163-3298 Table A3. Instantaneous evacuated canister method* air sampling results by task, NIOSH survey, June 2016 Task Description Diacetyl (ppb) 2,3-Pentanedione (ppb) 2,3-Hexanedione (ppb) Dumping beans from cooling bin into plastic bin 11.7 9.0 1.4 Dumping beans from cooling bin into plastic bin 22.6 15.8 1.6 Dumping beans from cooling bin into plastic bin 8.2 5.5 <1.0 Dumping beans from cooling bin into plastic bin 8.0 6.6 1.1 During auto-fill from auto-fill machine (packaging) 16.9 14.1 2.5 During auto-fill from auto-fill machine (packaging) 17.1 15.0 3.1 During auto-fill near roaster (packaging) 21.5 22.1 1.8 Grinding 12 oz bag; dark roast 30.8 28.6 2.9 Grinding 5-pound bag; dark roast 36.7 35.6 2.0 Grinding 5-pound bag; dark roast 50.4 46.6 4.8 Hand blending 6 lbs of roasted coffee 30.4 26.2 1.4 Pulling sample of roasted beans from roaster to check quality of beans 21.4 17.7 2.3 Pulling sample of roasted beans from roaster to check quality of beans 14.1 10.6 <1.8 Pulling sample of roasted beans from roaster to check quality of beans 11.8 10.3 <1.6 Pulling sample of roasted beans from roaster to check quality of beans 11.5 11.5 <16.4 Vacuuming chaff from roaster exhaust 13.3 11.8 <0.9 Vacuuming chaff from roaster exhaust 14.5 13.6 1.4 Vacuuming chaff from roaster exhaust 14.0 12.8 1.1 Note: NIOSH=National Institute for Occupational Safety and Health; ppb=parts per billion; < indicates below the limit of detection. *Sampling duration approximately 30 seconds; task-based air samples were collected by placing the inlet of the canister sampler in the employee’s personal breathing zone as he/she performed work task to mimic exposure.
Health Hazard Evaluation Report 2015-0163-3298 Page 31 , June 2016 ce, NIOSH survey esults by sour sampling r air * method able A4. Instantaneous evacuated canister T Source Description Diacetyl (ppb) 2,3-Pentanedione (ppb) 2,3-Hexanedione (ppb) At transfer point of auto-fill into 12 oz bags; packaging medium/dark roast 5.6 4.8 <1.3 At transfer point of auto-fill into 12 oz bags; packaging medium/dark roast 9.1 7.0 <1.1 At transfer point of auto-fill into 5-pound bags 5.5 4.5 <1.1 Note: NIOSH=National Institute for Occupational Safety and Health; ppb=parts per billion; < indicates below the limit of detection. *Sampling duration approximately 30 seconds; source air samples were collected by placing the inlet of the canister sampler near roasted beans. Table A5. Headspace analysis results* for bulk samples of roasted coffee beans, NIOSH survey, June 2016 Diacetyl 2,3-Pentanedione 2,3-Hexanedione Sample Type Bulk Sample Description (ppb) (ppb) (ppb) Coffee beans Medium-dark blend 2,402 2,627 <310 Coffee beans Decaffeinated roast 3,434 4,145 <310 Coffee beans Light-medium roast 2,174 2,458 <316 Coffee beans Light-medium blend 1,515 1,678 <310 Coffee beans Dark roast 1,983 1,928 <314 Note: NIOSH=National Institute for Occupational Safety and Health; ppb=parts per billion.
Page 32 Health Hazard Evaluation Report 2015-0163-3298

Table A6. Summary of continuous area air monitoring results for carbon dioxide, 

carbon monoxide, temperature, relative humidity, and total volatile organic compounds, 

NIOSH industrial hygiene survey, June 2016

Location 

Grinder, day 1

CO2 (ppm)*

583

(194–1259)

CO (ppm)*

2.8 

(0.1–90.2)

Temperature 

(°F)*

74.2

(22.2–76.4)

Relative 

humidity 

(%)*

50.3

(14.3–65.9)

Total VOC 

(ppb)*

585

(80–13,012)

Roaster, day 1 620

(378–957)

1.9

(0.6–4.2)

80.8

(45.1–86.5)

39.5

(26.5–62.2) ̶

Grinder, day 2 548

(511–694)

1.76

(<0.1–74.4)

72.5

(70.8–74.4)

44

(40.0–50.0)

382

(31–2882)

Roaster, day 2 550

(295–687)

1.5

(<0.1–2.5)

80.0

(40.4–96.3)

33.3

(14.1–50.1) ̶

Note: NIOSH=National Institute for Occupational Safety and Health; CO2=carbon dioxide; CO=carbon 

monoxide; ppm=parts per million; °F=degrees Fahrenheit; VOC=volatile organic compounds; 

“-“indicates the measurement was not recorded. 

*Mean concentration shown with range of measurements shared in the parentheses. 

Table A7. Summary of continuous personal air measurements for carbon monoxide, 

NIOSH industrial hygiene survey, June 2016

Job Title Work Area CO (ppm)*

Roaster Roaster 2.1 

(0–13)

Roaster Roaster 2.1

(0–5)

Roaster Roaster 0.8

(0–19)

Production Production 3.7

(0–63)

Production Production 3.0

(0–31)

Production Manager Production and Administrative 3

(0–26)

Production Delivery Production 2.8

(0–24)

Production Delivery Production 0.3

(0–24)

Note: NIOSH=National Institute for Occupational Safety and Health; CO=carbon monoxide; ppm=parts 

per million; < indicates below the limit of detection; *Mean concentrations shown with range of 

measurements shown in the parentheses. 
Health Hazard Evaluation Report 2015-0163-3298 Page 33 , June 2016 eported symptoms, NIOSH medical survey evalence of r A8. Prable T Symptom Experienced in the last 12 months N = 15 Number (%) Experienced in the last 4 weeks N = 15 Number (%) Nose symptoms* 12 (80%) 5 (33%) Eye symptoms† 7 (47%) 5 (33%) Sinusitis or sinus problems 3 (20%) 0 (0%) Problem with ability to smell 1 (7%) — Phlegm on most days for 3 months 1 (7%) — Lower respiratory symptoms (reported at least one of the following) 5 (33%) 1 (7%) Chest wheezing or whistling 5 (33%) 0 (0%) SOB on level ground or walking up a slight a hill 0 (0%) — Breathing trouble 2 (13%) 0 (0%) Awoke with chest tightness 1 (7%) 0 (0%) Awoke with shortness of breath 1 (7%) 0 (0%) Usual cough 1 (7%) 1 (7%) Asthma attack 1 (7%) 0 (0%) Systemic symptoms(reported at least one of the following) 7 (47%) 2 (13%) Flu-like achiness or achy joints 7 (47%) 2 (29%) Fever or chills 3 (20%) 0 (0%) Unusual tiredness or fatigue 2 (13%) 0 (0%) the symptom. 2) stinging, burning nose. week question was asked for eath; “-“=no four , or runny nose or 2) stinging, burning eyes. of participants; SOB=shortness of br both of the following: 1) stuffy, itchy , itchy eyes or both of the following: 1) watery Note: N=number *Nose symptoms includes one or †Eye symptoms includes one or
Page 34 Health Hazard Evaluation Report 2015-0163-3298

Table A9. Adjusted* comparisons of symptoms and self-reported physician diagnosis among 

NIOSH medical survey participants with U.S. adult population (N=15) June 2016

Health condition Comparative 

population†

Observed 

Number

Expected 

Number

SMR

(95% CI) ‡

Watery, itchy eyes last 12 months NHANES III 7 6.6 1.1 (0.5–2.2)

Stuffy, itchy, or runny nose last 12 months NHANES III 12 9.4 1.3 (0.7–2.2)

Sinus problems last 12 months NHANES III 3 6.0 0.5 (0.2–1.5)

Phlegm 3 consecutive month or more NHANES III 1 0.9 1.0 (0.2–6.0)

Wheeze last 12 months NHANES 2007-2012 5 2.1 2.4 (1.0–5.6)

Ever asthma (physician-diagnosed) NHANES 2007-2012 1 2.6 0.4 (0.1–2.2)

Current asthma (physician-diagnosed) NHANES 2007-2012 1 1.3 0.8 (0.1–4.3)

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. 

†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 

U.S. adult population and are shown in bold.
Health Hazard Evaluation Report 2015-0163-3298 Page 35

References

ACGIH® (American Conference of Governmental Industrial Hygienist) [2017a]. 2017 

TLVs® and BEIs®: Threshold limit values for chemical substances and physical agents 

and biological exposure indices. Cincinnati, OH: American Conference of Governmental 

Industrial Hygienists. 

ACGIH® [2017b]. Chemicals Substances and Other Issues Under Study (TLV®-CS). 

Available at: http://www.acgih.org/tlv-bei-guidelines/documentation-publications-anddata/ under-study-list/chemical-substances-and-other-issues-under-study-tlv. Date accessed: 

November 2017.

Akiyama M, Murakami K, Ohtani N, Iwatsuki K, Sotoyama K, Wada A, Tokuno K, Iwabuchi 

H, Tanaka K [2003]. Analysis of volatile compounds released during the grinding of roasted 

coffee beans using solid-phase microextraction. J Agric Food Chem 51(7):1961-1969.

Akpinar-Elci M, Travis WD, Lynch DA, Kreiss K [2004]. Bronchiolitis obliterans syndrome 

in popcorn production plant workers. Eur Respir J 24(2):298-302.

Anderson BA, Shimoni E, Liardon R, Labuza P [2003]. The diffusion kinetics of carbon 

dioxide in fresh roasted and ground coffee. J Food Eng 59:71-78.

ANSI (American National Standards Institute)/ASHRAE [2016]. Ventilation for acceptable 

indoor air quality, standard 62.1-2016. Atlanta, GA: ASHRAE.

Bailey RL, Cox-Ganser JM, Duling MG, LeBouf RF, Martin SB Jr, Bledsoe TA, Green 

BJ, Kreiss K [2015]. Respiratory morbidity in a coffee processing workplace with sentinel 

obliterative bronchiolitis cases. Am J Ind Med 58(12):1235-1245.

Berger KI, Reibman J, Oppenheimer BW, Vlahos I, Harrison D, Goldring RM [2013]. 

Lessons from the World Trade Center disaster: airway disease presenting as restrictive 

dysfunction. Chest 144(1):249-257. 

Burney PGJ and Chinn S [1987]. Developing a new questionnaire for measuring the 

prevalence and distribution of asthma. Chest 91 (6 Suppl):79S-83S.

Burney PGJ, Luczynska C, Chinn S, Jarvis D [1994]. The European community respiratory 

health survey. Eur Respir J 7(5):954-960.

CDC (Centers for Disease Control and Prevention) [1996]. Third National Health and 

Nutrition Examination Survey, 1988–1994, NHANES III Examination Data File [CDROM]. 

Hyattsville, Maryland: U.S. Department of Health and Human Services, Centers for Disease 

Control and Prevention. (Public use data file documentation No. 76300.)
Page 36 Health Hazard Evaluation Report 2015-0163-3298

CDC [2013]. Obliterative bronchiolitis in workers in a coffee-processing facility—Texas, 

2008–2012. Morb Mortal Wkly Rep 62(16):305–307.

CDC [2017a]. National Center for Health Statistics. National Health and Nutrition 

Examination Survey Data. Hyattsville, MD: U.S. Department of Health and Human Services, 

Centers for Disease Control and Prevention, [2007–2012]. Available at: https://wwwn.cdc.

gov/nchs/nhanes/default.aspx.Date accessed: November 2017.

CDC [2017b]. Smoking & tobacco use: quit smoking. Available at: https://www.cdc.gov/

tobacco/stateandcommunity/tobacco_control_programs/index.htm. Date accessed: November 

2017.

CFR. Code of Federal Regulations. Washington, DC: U.S. Government Printing Office, 

Office of the Federal Register.

Daglia M, Papetti A, Aceti C, Sordelli B, Spini V, Gazzani G [2007]. Isolation and 

determination of α-dicarbonyl compounds by RP-HPLC-DAD in green and roasted coffee. J 

Agric and Food Chem 55(22):8877-8882.

Day G, LeBouf RF, Grote A, Pendergrass S, Cummings KJ, Kreiss K, and Kullman G [2011]. 

Identification and measurement of diacetyl substitutes in dry bakery mix production. J Occ 

Env Hygiene 8(2):93-103.

de Assumpção MS, Gonçalves RM, Martins R, Bobbio TG, Schivinski CI [2016]. Reference 

Equations for Impulse Oscillometry System Parameters in Healthy Brazilian Children and 

Adolescents. Respir Care 61(8):1090-1099.

Desiraju K, Agrawal A [2016]. Impulse oscillometry: The state-of-art for lung function 

testing. Lung India 33(4):410-416. 

Duling MG, LeBouf RF, Cox-Ganser JM, Kreiss K, Martin SB Jr, Bailey RL [2016]. 

Environmental characterization of a coffee processing workplace with obliterative 

bronchiolitis in former workers. J Occup Environ Hyg 13(10):770-781.

Dweik RA, Boggs PB, Erzurum SC, Irvin CG, Leigh MW, Lundberg JO, Olin AC, Plummer 

AL, Taylor DR; American Thoracic Society Committee on Interpretation of Exhaled Nitric 

Oxide Levels (FENO) for Clinical Applications [2011]. An official ATS clinical practice 

guideline: interpretation of exhaled nitric oxide levels (FENO) for clinical applications. Am J 

Respir Crit Care Med 184(5):602-615.

EAACI Task Force on Occupational Rhinitis, Moscato G, Vandenplas O, Gerth Van Wijk R, 

Malo JL, Quirce S, Walusiak J, Castano R, De Groot H, Folletti I, Gautrin D, Yacoub MR, 

Perfetti L, Siracusa A [2008]. Occupational rhinitis. Allergy 63(8):969-980. 
Health Hazard Evaluation Report 2015-0163-3298 Page 37

ECRHS (European Community Respiratory Health Survey) [2014]. Questionnaires, 

protocols and instructions. Available at: http://www.ecrhs.org/Quests.htm. Date accessed: 

November 2017.

Ferris BG [1978]. Epidemiology standardization project. AmRev Respir Dis 

118(Suppl):1–53.

Figley KD, Rawling FF [1950] Castor bean: an industrial hazard as a contaminant of green 

coffee dust and used burlap bags. J Allergy 21:545–553.

Hankinson JL, Odencrantz JR, Fedan KB [1999]. Spirometric reference values from a sample 

of the general U.S. population. Am J Respir Crit Care Med 159(1):179–187.

Henneberger PK Redlich CA, Callahan DB, Harber P, Lemière C, Martin J, Tarlo SM, 

Vandenplas O, Torén K; ATS Ad Hoc Committee on Work-Exacerbated Asthma [2011]. An 

official American Thoracic Society statement: work-exacerbated asthma. Am J Respir Crit 

Care Med 184(3):368–378.

Hubbs AF, Cumpston AM, Goldsmith WT, Battelli LA, Kashon ML, Jackson MC, Frazer 

DG, Fedan JS, Goravanahally MP, Castranova V, Kreiss K, Willard PA, Friend S, SchweglerBerry, Fluharty KL, Sriram K [2012]. Respiratory and olfactory cytotoxicity of inhaled 

2,3-pentanedione in Sprague-Dawley rats. Am J Pathol 181(3)829-44. 

Kanwal R, Kullman G, Piacitelli C, Boylstein R, Sahakian N, Martin S, Fedan K, Kreiss K 

[2006]. Evaluation of flavorings-related lung disease risk at six microwave popcorn plants.

J Occup Environ Med. 48(2):149-57.

Karr RM, Davies RJ, Butcher BT, Lehrer SB, Wilson MR, Dharmarajan V, Salvaggio JE 

[1978]. Occupational asthma. J Allergy Clin Immunol 61(1):54–65.

Kim TJ, Materna BL, Prudhomme JC, Fedan KB, Enright PL, Sahakian NM, Windham GC, 

Kreiss K [2010]. Industry-wide medical surveillance of California flavor manufacturing 

workers: cross-sectional results. Am J Ind Med. 53(9):857-65.

King MS, Eisenberg R, Newman JH, Tolle JJ, Harrell FE Jr, Nian H, Ninan M, Lambright 

ES, Sheller JR, Johnson JE, Miller RF [2011]. Constrictive bronchiolitis in soldiers returning 

from Iraq and Afghanistan. N Engl J Med 365(3):222–230.

Komarow HD, Myles IA, Uzzaman A, Metcalfe DD [2011]. Impulse oscillometry in the 

evaluation of diseases of the airways in children. Ann Allergy Asthma Immunol 106(3):191-

199. 

Kreiss K [2013]. Occupational causes of constrictive bronchiolitis. Curr Opin Allergy Clin 

Immunol 13(2):167-72.
Page 38 Health Hazard Evaluation Report 2015-0163-3298

Langford NJ [2005]. Carbon dioxide poisoning. Toicol Rev 24(4):229-235.

LeBouf RF, Stefaniak AB, Virji, MA [2012]. Validation of evacuated canisters for sampling 

volatile organic compounds in healthcare settings. J Environ Monit 14(3):977–983.

LeBouf RF, Simmons M [2017]. Validation of evacuated canisters for sampling volatile 

organic compounds in healthcare settings. J Occup Environ Hyg 14(5):343-348.

Lee JY, Seo JH, Kim HY, Jung YH, Kwon JW, Kim BJ, Kim HB, Lee SY, Jang GC, Song DJ, 

Kim WK, Shim JY, Kim HJ, Shin YJ, Park JW, Cho SH, Lee JS, Hong SJ [2012]. Reference 

values of impulse oscillometry and its utility in the diagnosis of asthma in young Korean 

children. J Asthma 49(8):811-816. 

Lehrer SB, Karr RM, Salvaggio JE [1978]. Extraction and analysis of coffee bean allergens. 

Clin Allergy 8(3):217-226.

Malmberg LP, Pelkonen A, Poussa T, Pohianpalo A, Haahtela T, Turpeinen M [2002]. 

Determinants of respiratory system input impedance and bronchodilator response in healthy 

Finnish preschool children. Clin Physiol Funct Imaging 22(1):64-71.

Miller MR, Hankinson J, Brusasco V, Burgos F, Casaburi R, Coates A, Crapo R, Enright 

P, van der Grinten CP, Gustafsson P, Jensen R, Johnson DC, MacIntyre N, McKay R, 

Navajas D, Pedersen OF, Pellegrino R, Viegi G, Wanger J, ATS/ERS Task Force [2005]. 

Standardisation of spirometry. Eur Respir J 26(2):319-338.

Morgan DL, Jokinen MP, Price HC, Gwinn WM, Palmer SM, Flake GP [2012]. Bronchial 

and bronchiolar fibrosis in rats exposed to 2,3-pentanedione vapors: implications for 

bronchiolitis obliterans in humans. Toxicol Pathol 40(3):448-465.

Morgan DL, Jokinen MP, Johnson CL, Price HC, Gwinn WM, Bousquet RW, Flake GP 

[2016]. Chemical reactivity and respiratory toxicity of the α-diketone flavoring agents: 

2,3-butanedione, 2,3-pentanedione, and 2,3-hexanedione. Toxicol Pathol 44(5):763–783.

Newbury W, Crockett A, Newbury J [2008]. A pilot study to evaluate Australian predictive 

equations for the impulse oscillometry system. Respirology 13(7):1070-1075.

Newton J [2002]. Carbon monoxide exposure from coffee roasting. Appl Occup Environ Hyg

17(9):600-602.

NIOSH (National Institute for Occupational Safety and Health) [2004]. NIOSH respirator 

selection logic. Department of Health and Human Services, Centers for Disease Control 

and Prevention, National Institute for Occupational Safety and Health DHHS (NIOSH) 

Publication No. 2005-100. Available at: https://www.cdc.gov/niosh/docs/2005-100/

pdfs/2005-100.pdf. Date accessed: November 2017.
Health Hazard Evaluation Report 2015-0163-3298 Page 39

NIOSH [2010]. NIOSH pocket guide to chemical hazards. Cincinnati, OH: U.S. Department 

of Health and Human Services, Centers for Disease Control and Prevention, National 

Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2010-168c. 

Available at: http://www.cdc.gov/niosh/npg/. Date accessed: November 2017.

NIOSH [2012]. Flavoring-related lung disease. Information for healthcare providers. 

Department of Health and Human Services, Centers for Disease Control and Prevention, 

DHHS (NIOSH) Publication No. 2012-148 (supersedes 2012-107). Available at: http://www.

cdc.gov/niosh/docs/2012-148/. Date accessed: November 2017.

NIOSH [2016]. Criteria for a recommended standard: occupational exposure to diacetyl 

and 2,3-pentanedione. U.S. Department of Health and Human Services, Centers for Disease 

Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) 

Publication No. 2016-111. Available at: https://www.cdc.gov/niosh/docs/2016-111. Date 

accessed: November 2017.

Nishimura F, Abe S, Fukunaga T [2003]. Carbon monoxide poisoning from industrial coffee 

extraction. JAMA 290(3):334.

Oldenburg M, Bittner C, Baur X [2009]. Health risks due to coffee dust. Chest 136(2):536-

544

Oppenheimer BW, Goldring RM, Herberg ME, Hofer IS, Reyfman PA, Liautaud S, Rom 

WN, Reibman J, Berger KI [2007]. Distal airway function in symptomatic subjects with 

normal spirometry following World Trade Center dust exposure. Chest 132(4):1275–1282.

OSHA (Occupational Safety and Health Administration) [1993]. Compliance and 

Enforcement Activities Affected by the PELs Decision. August 5, 1993 Memorandum. 

Available at: https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_

table=INTERPRETATIONS&p_id=21220. Date assessed: November 2017.

OSHA [2003]. Enforcement Policy for Respiratory Hazards Not Covered by OSHA 

Permissible Exposure Limits. January 24, 2003 Memorandum. Available at: https://www.

osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_

id=24749. Date assessed: November 2017.

OSHA [2008]. Sampling and analytical methods: Method 1013 – Acetoin and diacetyl. 

Available at: http://www.osha.gov/dts/sltc/methods/validated/1013/1013.html. Date assessed: 

November 2017.

OSHA [2010]. Sampling and analytical methods: Method 1016 – 2,3-pentanedione. 

Available at: http://www.osha.gov/dts/sltc/methods/validated/1016/1016.html. Date assessed: 

November 2017.
Page 40 Health Hazard Evaluation Report 2015-0163-3298

OSHA [2014]. OSHA Fact Sheet: Do you have work-related asthma? A guide for you and 

your doctor. Washington, D.C.: U.S. Department of Labor, Occupational Safety and Health 

Administration. Available at: https://www.osha.gov/Publications/OSHA3707.pdf. Date 

assessed: November 2017.

OSHA [2017]. Permissible exposure limits – annotated tables. Available at: 

https://www.osha.gov/dsg/annotated-pels/index.html. Date assessed: November 2017.

Park JH, Yoon JW, Shin YH, Jee HM, Wee YS, Chang SJ, Sim JH, Yum HY, Han MY [2011]. 

Reference values for respiratory system impedence using impulse oscillometry in healthy 

preschool children. Korean J Pediatr 54(2)64-68.

Pellegrino R, Viegi G, Brusasco V, Crapo RO, Burgos F, Casaburi R, Coates A, van der 

Grinten CP, Gustafsson P, Hankinson J, Jensen R, Johnson DC, MacIntyre N, McKay R, 

Miller MR, Navajas D, Pedersen OF, Wanger J [2005]. Interpretative strategies for lung 

function tests. Eur Respir J 26(5):948–968.

Raffel JB, Thompson J [2013]. Carbon monoxide from domestic coffee roasting: a case 

report. Ann Intern Med 159(11):795-796. 

Rhoades JW [1960]. Analysis of the volatile constituents of coffee. J Agric Food Chem 

8:136–141.

Rondón C, Campo P, Galindo L, Blanca-López N, Cassinello MS, Rodriguez-Bada JL, Torres 

MJ, Blanca M [2012]. Prevalence and clinical relevance of local allergic rhinitis. Allergy. 

67(10):1282-1288.

Rondón C, Campo P, Galindo L, Blanca-López N, Cassinello MS, Rodriguez-Bada JL, Torres 

MJ, Blanca M [2012]. Prevalence and clinical relevance of local allergic rhinitis. Allergy 

67(10):1282-8.

Rose JJ, Wang L, Xu Q, McTiernan CF, Shiva S, Tejero J, Gladwin MT [2017]. Carbon 

monoxide poisoning: pathogenesis, management, and future directions of therapy. Am J 

Respir Crit Care Med 195(5):596-606.

Sahay S, Gera K, Bhargava SK, Shah A [2016]. Occurrence and impact of sinusitis in 

patients with asthma and/or allergic rhinitis. J Asthma 53(6):635-643. 

Schulz H, Flexeder C, Behr J, Heier M, Holle R, Huber RM, Jörres RA, Nowak D, Peters 

A, Wichmann HE, Heinrich J, Karrasch S; KORA Study Group [2013]. Reference values 

of impulse oscillometric lung function indices in adults of advanced age. PLoS One

8(5):e63366. doi: 10.1371/journal.pone.0063366. 

Schulze J, Biedebach S, Christmann M, Herrmann E, Voss S, Zielen S [2016]. Impulse 

Oscillometry as a Predictor of Asthma Exacerbations in Young Children. Respiration 

91(2):107-114. 
Health Hazard Evaluation Report 2015-0163-3298 Page 41

Shaaban R, Zureik M, Soussan D, Neukirch C, Heinrich J, Sunyer J, Wjst M, Cerveri I, Pin 

I, Bousquet J, Jarvis D, Burney PG, Neukirch F, Leynaert B [2008]. Rhinitis and onset of 

asthma: a longitudinal population-based study. Lancet. 372(9643):1049-1057. 

Shibamoto T [2015]. Volatile chemicals from thermal degradation of less volatile coffee 

components. In: Preedy VR, ed. Coffee in health and disease prevention. New York: Elsevier, 

pp. 129–135.

Shi Y, Aledia AS, Tatavoosian AV, Vijayalakshmi S, Galant SP, George SC [2012]. Relating 

small airways to asthma control by using impulse oscillometry in children.

Allergy Clin Immunol 129(3):671-678. 

Smith HJ, Reinhold P, Goldman MD [2005]. Forced oscillation technique and impulse 

oscillometry. In: Gosselink R, Stam H, eds. European Respiratory Monograph 31: Lung 

Function Testing. Vol. 10. Wakefield, UK: European Respiratory Society Journals, pp. 72–

105.

Smith HJ (Hans-Juergen.Smith@CareFusion.com) [2015]. Questions about impulse 

oscillometry. Email of December 9, 2015, from Hans-Juergen Smith, CareFusion, to Rachel 

Bailey (feu2@cdc.gov), Respiratory Health Division, National Institute for Occupational 

Safety and Health, Centers for Disease Control and Prevention, Department of Health and 

Human Services. 

Song TW, Kim KW, Kim ES, Park JW, Sohn MH, Kim KE [2008]. Utility of impulse 

oscillometry in young children with asthma. Pediatr Allergy Immunol 19(8):763-768. 

Tarlo SM, Lemiere C [2014]. Occupational asthma. N Engl J Med 370:640-649.

Tarlo SM[2016].Update on work-exacerbated asthma. Int J Occup Med Environ Health

29(3):369-374. 

Thomas KE, Trigg CJ, Baxter PJ, Topping M, Lacey J, Crook B, Whitehead P, Bennett JB, 

Davies RJ [1991]. Factors relating to the development of respiratory symptoms in coffee 

process workers. Br J Ind Med 48(5):314–322.

Vogel J, Smidt U [1994] Impulse oscillometry. analysis of lung mechanics in general practice 

and clinic, epidemiological and experimental research.1st ed. Frankfurt: PMI-Verlagsgruppe. 

Weinstein DJ, Hull JE, Ritchie BL, Hayes JA, Morris MJ [2016]. Exercise-associated 

excessive dynamic airway collapse in military personnel. Ann Am Thorac Soc 13(9):1476-

1482.

Zuskin E, Valić F, Skurić Z [1979]. Respiratory function in coffee workers. Br J Ind Med

36(2):117–122.
Page 42 Health Hazard Evaluation Report 2015-0163-3298

Zuskin E, Kanceljak B, Skurić Z, Butković D [1985]. Bronchial reactivity in green coffee 

exposure. Br J Ind Med 42(6):415-420.
Health Hazard Evaluation Report 2015-0163-3298 Page 43

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Page 44 Health Hazard Evaluation Report 2015-0163-3298

Keywords: NAICS 311920 (Coffee roasting), Michigan, diacetyl, 2,3-pentanedione, 

2,3-hexanedione, coffee, carbon monoxide, carbon dioxide, volatile organic compounds 

(VOCs).
Health Hazard Evaluation Report 2015-0163-3298 Page 45

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: Tia McClelland 

Data Analysis Support: Nicole Edwards, Kathleen Fedan, and Brian Tift

Laboratory Support: Dru Burns, Kyle Hatcher, Ryan LeBouf, and Anand Ranpara

Site Visit Team Members: Michael Beaty, Brie Hawley, Christopher Mugford, and Randall 

Nett

Availability of Report

Copies of this report have been sent to the employer, employees, and union at the 

facility. The state and local 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/2015-0163-3298.pdf. 

All other HHE Reports may be found at http://www2a.cdc.gov/hhe/search.asp

Recommended citation for this report:

NIOSH [2017]. Health hazard evaluation report: Evaluation of exposures and 

respiratory health at a coffee roasting and packaging facility. By Nett RJ, Hawley 

B. 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. 2015-0163-3298.
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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