NIOSH HEALTH HAZARD EVALUATION REPORT

HETA # 2003-0112-2949

ConAgra Snack Foods

Marion, Ohio

December 2004

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports
ii

PREFACE

The Respiratory Disease Hazard Evaluations and Technical Assistance Program (RDHETAP) of the 

National Institute for Occupational Safety and Health (NIOSH) conducts field investigations of possible 

health hazards in the workplace. These investigations are conducted under the authority of Section 

20(a)(6) of the Occupational Safety and Health (OSH) Act of 1970, 29 U.S.C. 669(a)(6), or Section 

501(a)(11) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C. 951(a)(11), which authorize the 

Secretary of Health and Human Services, following a written request from any employers or authorized 

representative of employees, to determine whether any substance normally found in the place of

employment has potentially toxic effects in such concentrations as used or found.

RDHETAP also provides, upon request, technical and consultative assistance to federal, state, and local 

agencies; labor; industry; and other groups or individuals to control occupational health hazards and to 

prevent related trauma and disease. Mention of company names or products does not constitute

endorsement by NIOSH.

ACKNOWLEDGMENTS AND AVAILABILITY OF REPORT

This report was prepared by Drs. Richard Kanwal and Greg Kullman of the RDHETAP, Division of 

Respiratory Disease Studies (DRDS). Field assistance was provided by Chris Piacitelli, Randy Boylstein, 

and Thomas Jefferson. In addition, the following DRDS staff assisted in the medical survey: Diana 

Freeland, Jim Taylor, David Spainhour, Terry Rooney, Brian Tift, and Kathleen Fedan. Desktop

publishing was performed by Terry Rooney. Review and preparation for printing were performed by 

Penny Arthur.

Copies of this report have been sent to employee and management representatives at ConAgra Snack 

Foods and to the OSHA Regional Office. This report is not copyrighted and may be freely reproduced. 

The report may be viewed and printed from the following internet address: 

http://www.cdc.gov/niosh/hhe. Single copies of this report will be available for a period of three years 

from the date of this report. To expedite your request, include a self-addressed mailing label along with 

your written request to:

NIOSH Publications Office

4676 Columbia Parkway

Cincinnati, Ohio 45226

800-356-4674

After this time, copies may be purchased from the National Technical Information Service (NTIS) at 5825 

Port Royal Road, Springfield, Virginia 22161. Information regarding the NTIS stock number may be 

obtained from the NIOSH Publications Office at the Cincinnati address.

For the purpose of informing affected employees, copies of this report 

shall be posted by the employer in a prominent place accessible to the 

employees for a period of 30 calendar days.
iii

HIGHLIGHTS OF THE NIOSH HEALTH HAZARD EVALUATION

AT CONAGRA SNACK FOODS, MARION, OHIO

The National Institute for Occupational Safety and Health (NIOSH) evaluated exposures and worker health related 

to the production of microwave popcorn. This evaluation was requested by workers after a slurry room worker was 

found to have the same type of lung disease that has affected workers exposed to butter flavorings in other 

microwave popcorn plants. 

What NIOSH Did

# We measured the air concentrations of butter

flavoring chemicals at several locations within 

the microwave popcorn plant.

# We conducted a questionnaire survey focusing 

on symptoms, medical history, and work history.

# We tested workers’ lung function with

spirometry.

What NIOSH Found

# Air concentrations of diacetyl, a butter flavoring 

chemical known to cause injury to airways in 

animal studies, were highest in the slurry room. 

(Other areas in the plant had very low levels).

# The air concentrations of diacetyl in the slurry 

room were similar to those of other plants where 

mixers have developed lung disease.

# Some workers in the slurry room had abnormal 

lung function on NIOSH tests, indicating that 

some of them probably have been affected by 

breathing the butter flavorings. 

# Abnormal lung function in some packaging area 

workers may mean that they were affected by 

flavoring chemicals from the slurry room. 

What Managers Can Do

# Continue to require that any worker entering the 

slurry room wear a respirator at all times.

# Always keep the doors to the slurry room closed.

# Maintain appropriate ventilation to all areas of 

the plant at all times, and make sure the air 

pressure of the slurry room is less than that in the 

packaging area.

# Identify ways to add butter flavorings to oil such 

that dust or vapors from the flavorings do not 

contaminate the air (i.e. closed systems).

# Offer lung function tests on a regular basis to all 

workers that enter the slurry room and to all 

quality assurance workers that pop many dozens 

of bags of product in microwave ovens. 

# Regularly measure the concentrations of butter 

flavoring chemicals in the air to assure that

exposure controls are working.

# Train workers on the potential health risks from 

exposures to flavorings and on the best ways to 

minimize exposures.

What Employees Can Do

For all workers that enter the slurry room:

• Know how to properly wear and maintain your 

respirator.

• Wear your respirator 100 percent of the time 

when in the slurry room.

• Keep all containers of flavorings tightly closed 

when not in use.

• Understand and use all the exposure control

devices and work practices that decrease the

amount of flavorings in the air.

For quality assurance lab workers and all workers 

that enter the slurry room:

• Participate in spirometry tests offered by your 

employer.

• Promptly report any persistent shortness of 

breath or cough, or any problems with your 

eyes, nose, throat, or skin to your supervisor 

and your doctor and show them a copy of this 

page.

What To Do For More Information:

We encourage you to read the full report. If you 

would like a copy, either ask your health and 

safety representative to make you a copy or call 

1-513-841-4252 and ask for

HETA Report # 2003-0112-2949
iv

Health Hazard Evaluation Report 2003-0112-2949

ConAgra Snack Foods

Marion, Ohio

December 2004

Richard Kanwal, M.D., M.P.H.

Greg Kullman, Ph. D., C.I.H.

SUMMARY

NIOSH has identified evidence of fixed obstructive lung disease consistent with bronchiolitis obliterans 

in workers exposed to airborne butter flavoring chemicals at several microwave popcorn plants. In 2002, 

NIOSH learned that a worker who had mixed oil and butter flavorings for microwave popcorn production 

at the ConAgra Snack Foods plant in Marion, Ohio, had been diagnosed with severe fixed obstructive 

lung disease consistent with bronchiolitis obliterans. During an initial visit to the plant in January 2003, 

NIOSH identified production processes and work practices similar to those of other microwave popcorn 

plants. Specifically, workers handled many different butter flavorings in open containers and poured the 

flavorings into open tanks of heated soybean oil. The tanks did not have local exhaust ventilation and the 

workers did not use respiratory protection. Oil and flavoring mixing activities and all heated tanks were 

located in one room (slurry room) adjacent to the packaging line area, and the air pressure in this room 

was positive relative to the packaging line area. NIOSH proceeded to conduct a detailed health and 

environmental survey at this plant from March 3 to March 10, 2003, in order to characterize exposures 

and lung function in mixers and other workers. The main findings from this survey included:

• The mean time weighted average diacetyl air concentration in the slurry room was 1.14 parts per 

million parts air (ppm). This air concentration is similar to those measured by NIOSH at two 

other microwave popcorn plants where mixers also developed fixed obstructive lung disease. 

• Three of 12 current slurry room workers were found to have airways obstruction on NIOSH 

spirometry tests. Two did not respond to bronchodilators, while one did respond but the forced 

expiratory volume in the first second of exhalation (FEV1) remained below norma l. All three had 

normal diffusing capacity. These findings are consistent with bronchiolitis obliterans. 

• After adjustments to the slurry room ventilation by ConAgra, the slurry room was found to have 

negative air pressure relative to the packaging area. 

• The mean time weighted average diacetyl air concentration in the packaging area was 0.02 ppm.

• Five workers in the packaging area had fixed obstruction on spirometry, normal diffusing 

capacity, and no history of work in the slurry room. All were smokers but were relatively young 

(average age 36), making smoking a less likely explanation for their obstruction. If packaging 

area air concentrations of flavoring chemicals were higher in the past when the slurry room was 

under positive pressure, it is possible that some packaging area workers developed airways 

obstruction as a result.

• Two of 11 current quality assurance (QA) lab workers were found to have abnormal spirometry. 

One had obstruction that was unresponsive to bronchodilator and had a normal diffusing capacity. 

Another had restriction. Prior to the installation of an enclosure with exhaust ventilation for the 

microwave ovens, the average diacetyl air concentration in the QA lab at the ConAgra plant was 

0.018 ppm, compared to 0.56 ppm in the QA lab at another plant where five of six QA workers 

were found to have airways obstruction. 
v

At the ConAgra plant and other microwave popcorn plants, the pattern of lung function 

test abnormalitie s in workers who regularly mix butter flavorings with heated soybean oil

implies a risk for the development of fixed airways obstruction from inhalation of 

flavoring-related chemicals. Nearby packaging workers may also be at risk if flavoring 

chemicals or dust in the air of the slurry room contaminate the air in the packaging area. 

Recommendations for engineering controls, use of personal protective equipment, and 

medical surveillance for exposed workers are provided in this report.

Keywords: SIC 2099 (food preparations, not elsewhere classified); bronchiolitis obliterans, diacetyl, 

fixed obstructive airways disease, chronic obstructive pulmonary disease, butter flavoring, microwave 

popcorn, popcorn, flavorings.

Table of Contents

Preface ............................................................................................................................................. ii

Acknowledgments and Availability of Report.................................................................................. ii

Highlights of the NIOSH Health Hazard Evaluation....................................................................... iii

Summary ........................................................................................................................................ iv

Introduction..................................................................................................................................... 1

Background..................................................................................................................................... 1

Methods........................................................................................................................................... 2

Results............................................................................................................................................. 4

Discussion........................................................................................................................................ 8

Conclusions.................................................................................................................................... 11

Recommendations.......................................................................................................................... 11

References...................................................................................................................................... 14

Appendix A.................................................................................................................................... 32

Appendix B.................................................................................................................................... 36

Appendix C.................................................................................................................................... 46

Appendix D.................................................................................................................................... 50

Evaluation Criteria........................................................................................................................ 52

Health Hazard Evaluation Report No. 2003-0112-2949 Page 1

INTRODUCTION

The National Institute for Occupational Safety 

and Health (NIOSH) has evaluated the risk for 

occupational lung disease from inhalation

exposure to butter flavoring chemicals at several 

microwave popcorn plants. In December 2002, 

NIOSH received a request from current workers 

at the ConAgra Snack Foods plant in Marion, 

Ohio, to conduct a health hazard evaluation after 

a flavoring-exposed worker was diagnosed with 

lung disease.

BACKGROUND

In August 2000, NIOSH learned that eight

former workers of a microwave popcorn

production plant in Missouri had moderate to

severe fixed obstructive lung disease consistent 

with the rare illness, bronchiolitis obliterans. A 

NIOSH investigation at this plant revealed an 

excess of current workers with obstruction on 

spirometry testing. Increasing cumulative

exposure to diacetyl, the predominant butter

flavoring chemical present in the air of the plant, 

was associated with an increased prevalence of 

abnormal lung function.1 In animal exposure 

experiments conducted by NIOSH, rats exposed 

to vapors from a butter flavoring used at this 

plant developed severe injury to their airway

epithelium.2

In bronchiolitis obliterans, inflammation and

scarring occurs in the small airways of the lung 

and can lead to severe, permanent shortness of 

breath.3 The main respiratory symptoms are 

cough and shortness of breath on exertion that 

typically do not improve much when the worker 

goes home at the end of the workday or on

weekends or vacations. Usually symptoms are 

gradual in onset and progressive, but severe

symptoms can occur suddenly. Most cases do 

not respond to medical treatment. Lung function 

testing with spirometry generally reveals fixed 

airways obstruction, and some workers develop 

obstruction before they become symptomatic. 

Because medical treatment does not reverse the 

condition, some workers with severe disease

have been placed on lung transplant waiting

lists.4

In addition to lung disease, workers exposed to 

butter flavoring vapors may develop problems 

with their eyes and skin. Eye irritation is

common, and occasionally workers report

chemical burns of the eyes requiring medical 

treatment. Similarly, exposed workers may

report skin irritation, and one worker at another 

plant developed a disabling skin allergy to butter 

flavorings.4

Prior to the request for a health hazard

evaluation by ConAgra workers, NIOSH had

performed medical and environmental

evaluations at five microwave popcorn plants. 

In three of these plants, workers who performed 

mixing of soybean oil with butter flavorings, 

salt, and colorings, had fixed obstruction, normal 

diffusing capacity for carbon monoxide

(DLCO), and findings on high resolution

computerized tomography (HRCT) scans of the 

chest that were consistent with constrictive

bronchiolitis obliterans.1,5,6 In two plants,

workers on packaging lines near non-isolated 

tanks of heated oil and flavorings had higher 

than expected prevalences of obstruction on

spirometry tests.1,7 In one plant, five of six

workers who performed repeated microwave

popping of product for quality control had

obstruction.

1

 (Approximately 100 bags were 

popped per worker per work shift.)

In 2002, NIOSH learned that a worker who had 

mixed oil and butter flavorings for microwave 

popcorn production at the ConAgra Snack Foods 

plant in Marion, Ohio, had been diagnosed with 

severe fixed obstructive lung disease consistent 

with bronchiolitis obliterans. This worker was 

approximately 40 years of age and had not 

smoked for many years. The worker reported 

the onset of progressive shortness of breath on 

exertion approximately one year after beginning 

work at the plant. Several months later, the

worker’s condition worsened acutely. DLCO

testing was normal and an HRCT scan of the 

chest revealed mosaic attenuation on the

expiratory view, consistent with bronchiolitis 

obliterans.

After receiving the request for a health hazard 

evaluation, NIOSH visited the plant in January 

2003 to conduct a walkthrough survey. The 

walkthrough revealed production processes and 
Page 2 Health Hazard Evaluation Report No. 2003-0112-2949

work practices similar to those of other

microwave popcorn plants. There were several 

large (e.g., 500-gallon) tanks containing heated 

oil, butter flavorings, salt, and colorings in the 

mixing (slurry) room. Mixers handled liquid, 

paste, and powdered butter flavorings in open 

containers and poured them into open tanks of 

heated soybean oil without using respiratory

protection. The pouring of powdered butter

flavorings generated significant amounts of

airborne dust. The lids on many tanks did not 

seal tightly and no tanks had local exhaust

ventilation. A large garage-type door separated 

the slurry room from an adjacent large area

where the microwave popcorn packaging lines 

were located. The lower part of this door did 

not seal tightly with its frame, leaving an 

opening to the packaging area, and testing with 

smoke tubes showed the slurry room to be under 

positive air pressure relative to the packaging 

area (i.e., air moved out of the slurry room and 

into the packaging area). There were no tanks of 

heated oil and flavorings in the packaging area. 

The mixture of oil, flavorings, colorings, and 

salt was piped from the tanks in the slurry room 

to machines on the packaging lines where the 

mixture was combined with kernel popcorn and 

sealed in microwaveable bags. QA workers

performed repeated microwave popping of

product in a separate QA lab (up to 130 bags per 

worker per 12-hour work shift). Other areas of 

the plant included offices, a warehouse, and the 

press area (assembly of and printing on

microwave popcorn bags). All areas of the plant 

were ventilated by rooftop heating, ventilation, 

and air conditioning (HVAC) units. Based on 

these observations, NIOSH provided initial

recommendations to decrease potential

exposures in the slurry room, packaging area, 

and QA lab (Appendix A – NIOSH interim

report dated January 28, 2003). 

NIOSH proceeded to conduct a detailed health 

and environmental survey at this plant from 

March 3 to March 10, 2003, in order to 

characterize exposures and lung function in

mixers and other workers. 

METHODS

Medical Evaluation

All current workers were invited to participate. 

After obtaining signed, informed consent from

participants, NIOSH interviewers administered a 

standardized questionnaire to collect information 

on symptoms, medical diagnoses, smoking

history, work history, and work-related 

exposures. This questionnaire (Appendix B) 

included questions from the American Thoracic 

Society (ATS) standardized respiratory

symptom questionnaire8 and the 3

rd National

Health and Nutrition Examination Survey

(NHANES III),9supplemented with questions 

about respiratory, mucous-membrane, and 

constitutional symptoms, and work history. 

NIOSH technicians performed spirometry tests 

using a dry rolling seal spirometer interfaced to 

a personal computer and following American

Thoracic Society guidelines,10 with results

compared to spirometry reference values

generated from the Third National Health and 

Nutrition Examination Survey (NHANES III).11 

The largest forced vital capacity (FVC) and

forced expiratory volume in the first second of 

exhalation (FEV1) were selected for analysis. 

Obstruction was defined as an FEV1/FVC ratio 

and FEV1 below the lower limits of normal. 

Restriction was defined as an FVC below the 

lower limit of normal with a normal FEV1/FVC 

ratio. A mixed pattern (obstruction and

restriction) was defined as an FEV1/FVC ratio, 

FEV1, and FVC below the lower limits of

normal. Workers with evidence of airways

obstruction or a mixed pattern were

administered albuterol, a bronchodilator

medication used to treat obstructive lung

diseases such as asthma, and were then re-tested 

to see if the obstruction was reversible. 

Reversible obstruction was defined as an

improvement in the FEV1 of at least 12% and at 

least 200 milliliters after administration of 

albuterol. Participants with abnormal

spirometry results (airways obstruction,

restriction, or a mixed pattern) underwent

measurement of carbon monoxide diffusing

capacity of the lung (DLCO) to identify

evidence of lung disease apart from the airways 
Health Hazard Evaluation Report No. 2003-0112-2949 Page 3

as might be seen in individuals with

emphysema. NIOSH technicians followed ATS 

guidelines12 for performing DLCO, with an 

abnormal DLCO defined as below the lower

limit of normal compared to reference values.13

NIOSH mailed each participant his/her test

results on April 8, 2003. Participants with

abnormal test results were counseled to obtain 

additional medical evaluation. 

The observed number of workers with

respiratory symptoms, self-report of physician 

diagnosed respiratory disease, and abnormal

spirometry, were compared to the number

expected based on national data from NHANES 

III.9The resulting prevalence ratios were

controlled for gender, age group (17 to 39 years 

of age versus 40 to 69 years of age), raceethnicity (Caucasian, African-American, or

Mexican-American), and cigarette smoking

status (ever versus never). Ninety-five percent 

confidence intervals for the prevalence ratios 

were calculated using the method described by 

Kahn and Sempos.14

Epi InfoTM was used to calculate odds ratios and 

95 percent confidence intervals for abnormal

spirometry results in workers who had worked 

as mixers for at least 1.5 years compared to

other workers. 

Industrial Hygiene Evaluation

A preliminary plant site visit was made in 

January 2003 to review production processes

and worker exposures to aid the design of an 

industrial hygiene sampling plan. A crosssectional industrial hygiene survey was

conducted from March 3 to 6, 2003. Four day 

and two night production shifts were sampled 

for air contaminants during the production of 

microwave popcorn. Full-shift, personal and 

area samples were taken. Personal breathing 

zone samples were collected for several butterflavoring-related ketone compounds including

diacetyl, acetoin, and 2-nonanone. Area samples 

were collected for these three ketones plus total 

dust, respirable dust, particle size distributions, 

acetic acid, butyric acid, acetaldehyde, and total 

volatile organic compounds. Samples were

collected from various plant areas including the 

press area, warehouse, maintenance, office

areas, slurry room, QA lab, and packaging area. 

Samples were also collected outside to assess 

surrounding ambient contributions to worker

exposures. These samples were time-weighted 

over an 8 to 10-hour sampling period for each 

shift (except for the volatile organic compound 

which required shorter sample times -

approximately 6 hours or less to prevent

overloading). Sampling pumps were pre- and 

post-calibrated with each use, and field and

media blank samples were taken for quality

control purposes. 

Diacetyl, acetoin, and 2-nonanone were

collected on Anasorb® carbon molecular sieve 

tubes at a flow rate of 0.150 liters per minute 

(lpm). These samples were analyzed by gas 

chromatography (GC) according to NIOSH 

Manual of Analytical Methods (NMAM)15 2557 

and 2558. Semi-quantitative air samples for 

volatile organic compounds were collected on 

thermal desorption tubes at a flow rate of 0.02 

lpm and were analyzed by gas chromatography 

with a mass selective detector according to

NIOSH Method 2549.15 Total hydrocarbons

were collected on coconut shell charcoal (CSC) 

tubes at a flow rate of 0.05 lpm and analyzed by 

GC according to NIOSH Method 1550. 15 The 

total hydrocarbons concentrations in this report 

include the sum of all gas chromatographic

peaks in the spectrum minus diacetyl, acetoin, 

and 2-nonanone. Butyric and acetic acid were 

collected on silica gel sorbent tubes at a flow 

rate of 0.3 lpm and analyzed by high pressure 

liquid chromatography (HPLC) according to

NIOSH Method 7903. 15 Acetaldehyde was

collected on solid sorbent tubes (XAD-2) at a 

flow rate of 0.03 lpm and analyzed by GC 

according to NIOSH Method 2538. 15

Total dust samples were collected at a flow rate 

of 3.0 lpm on closed-face filter cassettes using 

37-mm poly vinyl chloride (PVC) filters with a 

pore size of 5 micrometers (μm). Respirable 

dust samples were collected at 4.2 lpm on

similar filters with BGI Respirable / Thoracic 

CyclonesTM (BGI Inc., Waltham, MA). The

cyclone has a median cut point for particles 4 

micrometer (μm) in aerodynamic diameter. The 

filters were analyzed gravimetrically according 

to NIOSH Methods 0500 and 0600,respectively.

15

 (NIOSH provided air sampling results for the 
Page 4 Health Hazard Evaluation Report No. 2003-0112-2949

ketones diacetyl, acetoin, and 2-nonanone, total 

dust, and respirable dust in an interim report 

dated October 2, 2003.) Particle size

distributions were collected using a 9 stage 

cascade impactor operated at a flow rate of 2.0 

lpm. The PVC filter samples were analyzed 

gravimetrically according to NIOSH Method

0500. 15

Grimm optical particle counters (OPC) (Grimm 

Technologies, Inc., Douglasville, GA) were used 

to measure real-time airborne particle

concentrations. The Grimm OPC

measurements were collected over eight to ten 

hour periods at selected area sampling locations.

A Gasmet DX-4010TM Fourier Transform

Infrared (FTIR) Gas Analyzer (Temet

Instruments Oy, Helsinki, Finland) was used to 

measure peak concentrations of diacetyl in the 

slurry room during mixing operations. The

instrument was operated in the center of the 

room to measure general area diacetyl

concentrations throughout the work shift.

RESULTS

Except where noted, the following results were 

provided to ConAgra Snack Foods and the HHE 

requestors in the October 2003 interim report. 

Medical Survey

Sixty-five percent of the workforce participated 

in the medical survey. Participation by work 

area is shown in Table 1, along with the mean 

age, percentage of males, and percentage of

current or former smokers among participants. 

Partic ipation in five work areas (press, slurry

room, packaging area, QA lab, and maintenance) 

was good, ranging from 70 to 100 percent. 

Participation of office and warehouse workers 

was low (34% and 27% respectively), limiting 

their use as a minimally or un-exposed group 

(i.e., internal control) to which the prevalences 

of symptoms, self-reported diagnoses, and

spirometry abnormalities in microwave popcorn 

production workers could be compared. 

Potential exposures to printing-related chemicals 

in the press area, which could lead to symptoms 

and/or health effects, limited the use of press 

area workers as an internal control group. 

Twenty four of 26 participating mechanics

reported spending time in the slurry room every 

week (mean 2 hours; range 0.5 to 10 hours),

which limited their use as an internal control 

group. 

Table 2 lists the numbers and percentages of

workers with symptoms by work area. The 

responses of four mechanics who work mostly in 

the press area are included with those of the 

press workers. All other mechanics are included 

in the “other” category along with the

participants from the office and warehouse. 

Compared to workers in other plant areas, slurry 

room and QA lab workers had the highest

percentages of workers reporting of shortness of 

breath on exertion (33% of mixers and 36% of 

QA workers participating in the survey), 

wheezing or whistling in chest without a cold

(50% of mixers, 36% of QA workers), unusual 

fatigue (33% of mixers, 36% of QA workers), 

and nose bleeds (25% of mixers, 18% of QA

workers). Nasal irritation was reported by a

high percentage of all workers, especially in

production (highest in mixers at 83%). Eye

irritation was reported frequently by workers in 

all work areas (28% to 45% of workers). Skin 

problems were most frequently reported by

workers in the press area (34% of workers). 

Table 3 lists the numbers and percentages of

workers with abnormal lung function on NIOSH 

tests and that reported that they had a respiratory 

diagnosis confirmed by a physician. The

responses and test results of four mechanics that 

work mostly in the press area are included with 

those of the press workers. All other mechanics 

are included in the “other” category along with 

the participants from the office and warehouse. 

Twenty-nine of the 205 survey participants 

(14%) had abnormal spirometry. Only four of 

19 with obstruction or a mixed pattern had a 

response to bronchodilator documenting

reversibility. The slurry room had the highest 

percentage of workers with abnormal spirometry 

(33% of workers tested), including the highest 

percentage with obstruction or a mixed pattern 

(25%). Bronchitis while working at the plant 

was reported most frequently by slurry room and 

QA workers (33% of mixers, 36% of QA

workers). Asthma was reported most frequently 
Health Hazard Evaluation Report No. 2003-0112-2949 Page 5

and by similar percentages of packaging, slurry 

room, and QA workers (16% to 18% of

workers). 

Tables 4, 5 and 6 show the numbers of ConAgra 

packaging area, slurry room and QA lab, and 

press area workers reporting respiratory

symptoms and diagnoses and having abnormal 

results on NIOSH spirometry tests, compared to 

the numbers that would be expected based on 

national data from NHANES III (after adjusting 

for age, race, sex, and smoking history). The 

ratio of the observed number to the expected

number (prevalence ratio) gives an indication of 

how similar or different the observed number is 

to the expected number. The closer the ratio is 

to “1”, the less unusual is the observed number. 

If the 95 percent confidence interval indicated 

includes “1”, then the difference between the

observed and the expected number is not

statistically significant (i.e., the probability that 

the difference is due to chance is greater than 

five percent). Slurry room and QA lab workers 

were combined into one group due to the small 

numbers of workers in each group, and because 

of the known occurrence of increased risk in 

both these groups in other microwave popcorn 

plants. Shortness of breath on exertion was

reported 1.6 times more often than expected by 

slurry room/QA workers but this excess was not 

statistically significant. Wheezing apart from

colds was reported 2.1 times more often than 

expected by packaging area workers

(statistically significant), 3.0 times more often 

than expected by slurry room/QA workers

(statistically significant), and 1.9 times more

often than expected by press area workers

(borderline statistically significant). Chronic 

bronchitis was reported 3.3 times more often

than expected by press area workers (statistically 

significant). Asthma was reported 

approximately twice as often as expected in

packaging area and slurry/QA workers

(statistically significant excess for packaging

area workers). Obstruction or a mixed pattern 

on NIOSH spirometry tests was found 1.6 times 

as often as expected in packaging area workers 

(not statistically significant), 2.5 times as often 

as expected in slurry/QA workers (borderline 

statistically significant), and 1.8 times as often 

as expected in press area workers (not

statistically significant).

The prevalence ratios in Tables 4, 5, and 6 are 

slightly different from the ones listed in the

interim report of October 1, 2003 (Appendix C). 

The earlier ratios were based on expected

numbers that were only adjusted for age and

smoking status, whereas the ratios in this final 

report are based on expected numbers that are 

adjusted for age, race, sex, and smoking status. 

The only ratio that is substantially different from 

the ones previously reported is the one for 

chronic bronchitis in press area workers. 

A total of 39 participants reported current or past 

experience working as mixers in the slurry

room. Twelve of 39 reported currently working 

in the slurry room (nine as mixers and three as 

assistant supervisors) and eight reported that

they were former mixers. Nineteen reported 

having worked as mixers (even for as little as 

one day) while assigned to other jobs. Seven of 

39 (19%) had an abnormal spirometry test (four 

with obstruction or a mixed pattern, three with 

restriction). (In the October 2003 interim report, 

nine of 39 workers with mixing experience were 

reported to have abnormal spirometry. This 

number included two workers with borderline 

obstruction, defined as an FEV1/FVC ratio

below normal with a normal FEV1.) Nine of the 

20 with a current or former job title of mixer 

reported working in the slurry room for 1.5 or 

more years. Four of these nine had an abnormal 

spirometry test (three with obstruction or a

mixed pattern, one with restriction). (The 

October 2003 interim report stated “Six of these 

nine...” because the two borderline obstruction 

results were included.) Taking into account all 

survey participants, a worker with an abnormal 

spirometry test was 5.5 times more likely to 

have worked with a job title of mixer for 1.5 

years or more as opposed to having worked less 

time or no time as a mixer (95% confidence 

limits: 1, 27). (The October 2003 interim report 

stated “6.7 times more likely...” because of the 

inclusion of the borderline obstruction results.) 

Workers with only obstruction or a mixed

pattern were 5.6 times more likely to have

worked with a job title of mixer for 1.5 years or 

more as opposed to having worked less time or 

no time as a mixer (95% confidence limits: 0.8, 

29). Neither of these comparisons was

statistically significant (i.e., the probability that 

the outcome is due to chance is at least 5 % as 
Page 6 Health Hazard Evaluation Report No. 2003-0112-2949

the 95% confidence limits include 1). (In the 

October 2003 interim report, these comparisons 

were reported as statistic ally significant in error. 

However, the fact that the number of workers

that had worked as mixers for 1.5 or more years 

was small decreases the likelihood of finding 

statistical significance.)

Industrial Hygiene Survey

The predominant volatile organic compounds

identified in plant air are presented in Table 7 by 

sampling location. Diacetyl and limonene were 

identified as predominant compounds in the 

GCMS spectra from most plant areas. In

addition to diacetyl and limonene, the

predominant compounds in the slurry room

included acetoin, propylene glycol, acetoin

oligomers, ethanol, hexane, and tetrahydrofuran. 

The QA area had the most abundant spectra of 

organic compounds including both diacetyl and 

acetoin. The press room area and office area 

had the least abundant spectra of predominant 

organic compounds in air; diacetyl was a

predominant compound in the press area but was 

not detected among the predominant compounds

in the office area. 

Diacetyl concentrations ranged from below

detectable levels (approximately 0.004 parts per 

million parts air by volume – ppm) to a high of 

2.7 ppm (Table 8). The mean diacetyl

concentration from the 123 personal and area 

measurements was 0.15 ppm with a standard

deviation (STD) of 0.41. The mean diacetyl

concentration from the 48 area samples (0.17 

ppm) was similar to the mean concentration

from the 75 personal exposure measurements

(0.14 ppm). The mean acetoin concentration 

was slightly lower than diacetyl at 0.11 ppm 

from the 123 personal and area samples. 

Acetoin concentrations ranged from below

detectable limits (approximately 0.004 ppm) to a 

high of 2.8 ppm. Diacetyl and acetoin

concentrations below detectable levels (LOD) 

were assigned a value of 0.002 ppm (i.e.,

LOD/2) and those samples below quantifiable 

levels (LOQ) were assigned a value of 0.005 

ppm (i.e., LOQ/2) to calculate mean

concentrations. 

Figure 1 and Tables 9 and 10 present diacetyl 

and acetoin air concentrations by job location for 

both personal and area samples. The slurry 

room/mixers had the highest mean ketone

concentrations, 1.14 ppm for diacetyl and 0.90 

ppm for acetoin (personal and area samples

combined). The mean diacetyl concentration 

from the 7 personal samples from the slurry 

room was 1.03 ppm; the mean area

concentration from the slurry room (6 samples) 

was 1.26 ppm. Supervisors had the next highest 

diacetyl concentration with a mean of 0.15 ppm; 

this included area and personal measurements

from all supervisor categories including the

slurry room supervisor. The mean of the 11 

personal diacetyl exposure measurements

collected from the supervisor category were 0.17 

ppm, which was higher that the mean of the area 

samples collected from the supervisor’s office

(0.01 ppm). The packaging area had mean

diacetyl concentrations by job location ranging 

from 0.02 ppm (case packer) to 0.03 ppm

(palletizer). This inc luded several job

categories: phaser, case packer, cartoner, and

palletizer. The mean acetoin concentration in 

these production job categories was

approximately 0.01 ppm. The QA lab had a 

mean diacetyl concentration of 0.03 ppm for 

personal samples and 0.01 ppm for area samples. 

The mean acetoin concentration for the QA lab 

was 0.03 ppm from the personal samples and 

0.01 from the area samples. The mean diacetyl 

concentration from the warehouse area was 0.03

ppm for personal and area samples combined; 

the acetoin concentration was 0.004 ppm. The 

press area and office locations had mean diacetyl 

concentrations below 0.03 ppm and mean

acetoin concentrations below 0.01 ppm. The 

ambient sample collected upwind from the plant 

was below detectable levels for diacetyl and

acetoin (less than approximately 0.004 ppm). 

Currently there are no Occupational Safety and 

Health Administration (OSHA) Permissible

Exposure Limits (PELs), American Conference 

of Governmental Industrial Hygienists (ACGIH) 

Threshold Limit Values (TLVs), and NIOSH 

Recommended Exposure Limits (RELs) for

diacetyl, acetoin or 2-nonanone. 

Figure 2 provides an assessment of real- time 

concentrations for diacetyl, acetoin, and

nonanone in the slurry room. These sampling 

results were obtained using the FTIR on two

separate days, March 3

rd and 4th, 2004. 
Health Hazard Evaluation Report No. 2003-0112-2949 Page 7

Additionally, these sampling results were

collected from general room air and would not 

reflect potential peak exposures to mixers from

activities such as opening tank lids or manual 

handling of butter flavorings. The average

diacetyl and acetoin concentrations measured

using the FTIR were comparable to those

obtained using the NIOSH Manual of Analytical 

Methods (NMAM 2557 and 2558). The mean 

diacetyl concentration measured in the slurry

room on March 3

rd was 2.32 ppm (the

comparable diacetyl concentration measured by 

NMAM was 2.68 ppm). On March 4

th, the 

average diacetyl concentration measured using 

the FTIR was 1.86 compared to the NMAM

diacetyl concentration measure of 1.12 ppm. 

The peak diacetyl concentration in the slurry

room on March 3rd was 16.1 ppm, approximately 

7 times the average concentration. The peak 

diacetyl concentration on March 4

th

 was 5.3 

ppm, approximately 3 times the average

concentration on this day. Nonanone

concentrations were much lower, with mean

concentrations below 0.1 on both days. 

Figure 3 presents area diacetyl concentrations 

collected in side-by-side sampling in the slurry 

room using two different sampling flow rates, 

0.15 lpm (used by NIOSH) and 0.02 lpm (used 

by ConAgra consultants). This sampling was 

done at the request of plant management to

assess the impact of sampling flow rate on

diacetyl concentrations. The diacetyl

concentrations collected at the higher flow rate 

(3 samples) had a mean concentration of 0.71 

ppm and the samples collected at the lower flow 

rate (3 samples) had a mean diacetyl

concentration of 0.43 ppm. A flow rate of 0.15 

lpm (consistent with NMAM 2557 method for 

diacetyl), was chosen to quantify diacetyl at

lower airborne concentrations. 

Total hydrocarbon concentrations in air

(excluding diacetyl, acetoin, and nonanone)

ranged from below detectable limits to a high of 

5.53 milligrams per cubic meter of air (mg/m3) 

as seen in Table 11. (These data provide a 

perspective on the contributions of hydrocarbons 

other than the three ketones, diacetyl, acetoin, 

and 2-nonanone, since these three compounds 

were excluded from this analysis.) The mean

concentration from the 48 area samples was 1.25 

mg/m3 with a standard deviation of 0.92.

Twenty-seven of the hydrocarbon samples were 

below quantifiable limits (LOQ - approximately 

1.60 mg/m3) and assigned a value of 0.8 mg/m3

to calculate mean concentrations (LOQ/2). Four 

of the 48 samples were below detectable limits 

(LOD - approximately 0.44 mg/m3) and assigned 

a value of 0.22 mg/m3 to calculate mean

concentrations (LOD/2). Table 11 presents

hydrocarbon concentrations by sampling

location. The phaser operator area had the

highest hydrocarbon concentration, 2.06 mg/m3

(excluding diacetyl, acetoin, and 2-nonanone). 

The slurry room, supervisor, press operator, case 

packer, and QA all had a mean hydrocarbon 

concentrations between 1 mg/m3and 2 mg/m3. 

Currently there are no Occupational Safety and 

Health Administration (OSHA) Permissible

Exposure Limits (PELs), American Conference 

of Governmental Industrial Hygienists (ACGIH) 

Threshold Limit Values (TLVs) and NIOSH

Recommended Exposure Limits (RELs) for total 

hydrocarbon concentrations. 

Acetaldehyde concentrations ranged from

below detectable limits to a high of 0.17 ppm 

(Table 12). The 48 area acetaldehyde samples 

had a mean of 0.05 ppm with a standard

deviation of 0.05. Twenty-one of the

acetaldehyde samples were below quantifiable 

limits (approximately 0.036 ppm) and assigned a

value of 0.018 ppm (LOQ/2) to calculate mean 

concentrations. Six of the 48 samples were

below detectable limits (approximately 0.014

ppm) and assigned a value of 0.007 ppm to 

calculate mean concentrations. Table 12 presents 

acetaldehyde concentrations by sampling

location. The maintenance, press room and QA 

areas had the highest acetaldehyde

concentrations with a means ranging from 0.12 

ppm to 0.15 ppm. The highest concentration in

the slurry room was 0.05 ppm. Acetaldehyde 

mean concentrations in the production areas

were all below 0.05 ppm, and concentrations in

the office areas were all below quantifiable

levels. These levels are all below the OSHA 

PEL for acetaldehyde, 200 ppm as an eight-hour 

TWA. The ACGIH TLV for acetaldehyde is 25 

ppm as a ceiling concentration (C) not to be 

exceeded. NIOSH considers acetaldehyde to be 

a potential occupational carcinogen and
Page 8 Health Hazard Evaluation Report No. 2003-0112-2949

recommends that exposures be reduced to the 

lowest feasible concentration.

Most of the acetic and butyric acid samples 

were below quantifiable levels. Only 12 of the 

acetic acid samples had quantifiable

concentrations (greater than 0.004 ppm). The 

highest concentrations were in the mixing room 

where the highest acetic acid concentration was 

3.31 ppm Acetic acid was also detected at

quantifiable levels in other plant areas (the QA 

area, packaging lines, warehouse, office,

maintenance area) but concentrations in these 

areas were below 0.15 ppm. Only 3 of the 48 

butyric acid samples had detectable

concentrations and these were all from the slurry 

room. The highest butyric acid concentration 

was 0.16 ppm. These levels are all below the 

OSHA PEL, ACGIH TLV, and NIOSH REL for 

acetic acid, all 10 ppm as an eight-hour TWA. 

ACGIH and NIOSH also provide a short term 

exposure limit (STEL) recommendation of 15 

ppm. Currently, there is no OSHA PEL,

ACGIH TLV or NIOSH REL for butyric acid.

The total dust concentrations ranged from

below detectable levels (approximately 0.014

milligrams per cubic meter of air – mg/m3) to a 

high of 1.74 mg/m3, as presented in Table 13. 

The mean total dust concentration from the 49 

area samples was 0.24 mg/m3. Respirable dust

concentrations ranged from below detectable

levels (approximately 0.01 mg/m3) to a high of 

0.65 mg/m3. The mean respirable dust

concentration was 0.09 mg/m3. Total dust

samples below the limit of detection (LOD)

were assigned a value of 0.007 mg/m3(i.e., LOD 

/ 2) to calculate mean concentrations; respirable 

dust samples below the LOD were assigned a 

value of 0.005 mg/m3

The slurry room had the highest mean total and 

respirable dust concentrations, 1.1 and 0.49

mg/m3respectively (Figure 4). The packaging 

area had mean total dust concentrations ranging 

from 0.11 mg/m3(cartoner and palletizer) to

0.16 mg/m3 (phaser). Mean respirable dust

concentrations by location in the packaging area 

ranged from 0.03 to 0.05 mg/m3. The QA lab 

had a mean total dust concentration of 0.07

mg/m3 and a mean respirable dust concentration 

of 0.03 mg/m3. The office had the lowest total 

and respirable dust concentrations, 0.02 mg/m3

and 0.009 mg/m3 respectively. These levels are 

below the Occupational Safety and Health

Administration (OSHA) permissible exposure

limit (PEL) for particulates not otherwise

regulated (PNOR) of 15 mg/m3 as an eight-hour 

TWA (5 mg/m3 for respirable dust) and the

American Conference of Governmental

Industrial Hygienists (ACGIH®) threshold limit 

value (TLV®) for particulates not otherwise

specified (PNOS) of 10 mg/m3 for inhalable

particulates as an eight-hour TWA (3 mg/m3 for 

respirable particulate). 

Particle size distribution data from the four 

cascade impactor samples taken in the slurry 

room indicated that approximately 76 percent of 

the airborne mass was less than 10 micrometers

(μm) in aerodynamic diameter and in the

respirable size fraction. (The cascade impactor 

samples taken from other plant areas had

insufficient mass to assess particle size

distributions). Approximately 39 percent of the 

mass from these four slurry room samples was 

below 3.5 μm in aerodynamic diameter. Figures 

5 through 7 present particle count data obtained

using the GRIMM Optical Particle Counter in 

the slurry room, QA lab, and in packaging.

These figures show real-time particle count data 

in particles per cubic centimeter (Particles/cc) by 

five partic le size categories: 0.3 to 0.5 μm, 0.5 to 

1.0 μm, 1.0 to 5.0 μm, 5.0 to 10.0 μm, and 

greater than 10 μm. The samples collected from 

the slurry room had the highest particle count 

concentrations in all 5 size categories; these

samples also had greater fluctuations in

concentration throughout the workshift than the 

samples collected in the QA area or the

production (palletizing area). 

DISCUSSION

Nature of the Disease

Bronchiolitis obliterans is a rare lung disease

characterized by inflammation and scarring of 

the small airways of the lung, which can lead to 

severe, permanent shortness of breath. The

constrictive form of bronchiolitis obliterans can 

occur after inhalation of nitrogen dioxide, silo 

gases, ammonia, chlorine, hydrogen fluoride,
Health Hazard Evaluation Report No. 2003-0112-2949 Page 9

ozone, phosgene, fly ash, and sulfur dioxide.3In 

occupational settings, an incident of

overexposure often results in severe initial

symptoms of pulmonary edema, followed by

apparent recovery. Persistent shortness of breath 

occurs weeks later due to bronchiolitis

obliterans. Apart from work-related exposures, 

most bronchiolitis obliterans cases are due to

bone marrow or lung transplants. When

bronchiolitis obliterans develops insidiously, as 

in the case of post-transplant patients, there are 

often no respiratory symptoms during the early 

stages of disease, even though lung function

tests may be abnormal.16 As lung function 

continues to decline, respiratory symptoms

eventually develop. Several workers that have 

developed bronchiolitis obliterans in the setting 

of butter flavoring exposure during microwave 

popcorn production,4and during the manufacture 

of flavorings,17,18 have experienced a slow onset 

of symptoms similar to post-transplant patients. 

In affected individuals, lung function testing

with spirometry typically shows obstruction

(low FEV1/FVC ratio and FEV1) that does not 

improve with use of an inhaled bronchodilator. 

In moderate to severe disease, increased residual 

volume may occur. The chest x-ray is usually 

normal, but high resolution lung computerized 

tomography with inspiratory and expiratory

views may show mosaic attenuation on the

expiratory view. The diagnosis of bronchiolitis 

obliterans is likely when the clinical history

includes one of the known causes, the more 

common lung diseases are ruled out, and the 

above spirometry and radiology findings are

present. The diagnosis can be confirmed by

identifying bronchiolitis in an open (or

thoracoscopic) lung biopsy specimen. However,

the pathologic process in the lung is patchy in 

distribution, and it is only with great care,

special stains, and the examination of many

biopsy sections that the typical lesion can be

identified. Because the process of obtaining the 

tissue is invasive and the yield is not certain, 

affected individuals and their physicians should 

discuss in detail whether or not a lung biopsy for 

a tissue diagnosis is warranted.

Exposures to Flavoring-Related Chemicals

Flavorings are often complex mixtures of

ingredients, many of which can be irritating to 

the skin, eyes, and respiratory system.19 The

effects of these ingredients may be additive,

such that exposures to concentrations of

compounds that would not cause harm as a sole 

exposure may be harmful if combined with

exposures to other compounds. NIOSH

measured the air levels of diacetyl and acetoin, 

two common ingredients in butter flavoring, as 

indicators of exposure to butter flavoring vapors. 

Animal experiments at NIOSH indicate that

diacetyl is one of the chemicals in butter

flavoring that can lead to airway injury.20 The 

other chemical components that may contribute 

to toxicity, and the levels of exposure that are 

considered safe, are still not known. 

Recommended air exposure limits have not been 

established for most chemicals used in

flavorings.19 Also unknown is the relative safety 

of powdered flavorings compared to liquids or 

pastes. Powders that are formulated (i.e.,

encapsulated) to have lower emissions of

volatile flavoring chemicals may pose lower

risk. However, inhalation of powder of

respirable size during the handling of these 

flavorings may increase worker risk for lung 

problems (due to deposition and local release of 

flavoring chemicals on contact with water in the 

airways). The particulates measured in the

slurry room had a substantial respirable dust 

fraction (approximately 76%); these respirable 

dusts would be capable of penetrating to the 

distal regions of the lung where bronchiolitis 

obliterans occurs.

Patterns of Lung Function Test

Abnormalities in Different Illnesses

Evaluation of lung function with spirometry can 

reveal several patterns of abnormal lung

function. With obstruction, the movement of air 

out of the lungs is slowed because airways are 

narrowed or blocked. Obstruction occurs with 

diseases such as asthma, emphysema, or

bronchiolitis obliterans. Obstruction due to

asthma can be reversed by the administration of 

a bronchodilator medication. With emphysema 

due to smoking, the obstruction is usually fixed 

(i.e., no significant response to bronchodilator 
Page 10 Health Hazard Evaluation Report No. 2003-0112-2949

medication). A diffusing capacity test for

carbon monoxide (DLCO) is usually abnormally 

low with emphysema because there is associated 

damage to the lungs apart from the airways. 

With bronchiolitis obliterans, the obstruction is 

fixed and the DLCO is usually normal because 

the lung tissue apart from the airways is not 

affected. Restriction is manifested on

spirometry by a decreased FVC, meaning that a 

lower than normal amount of air is exhaled after 

a maximal inhalation. Restriction results when a 

disease process causes scarring of lung tissue so 

that it is no longer fully able to expand. The 

scarring of lung tissue results in a low DLCO. 

Table 14 summarizes the test findings in

obstructive and restrictive lung diseases. 

Exposures and Worker Health at ConAgra 

Snack Foods, Marion, Ohio

Slurry room: Three of 12 current slurry room 

workers (mixers and supervisors) were found to 

have obstruction on NIOSH spirometry. Two 

did not respond to bronchodilators, while one 

did respond but the FEV1 remained below

normal. All three had normal diffusing capacity. 

These findings are consistent with bronchiolitis 

obliterans, and when considered along with

similar findings in former mixers in this plant 

and others, strongly suggest that exposures to

flavoring chemicals in the slurry room pose a

risk for the development of occupational lung 

disease. It is likely that some slurry room

workers have been affected by this exposure. In 

two other plants with affected mixers evaluated 

by NIOSH, diacetyl air concentrations in the oil 

and flavoring mixing room/area were similar to 

those in the slurry room at the ConAgra plant.5,6

The fact that the diacetyl levels at these two

other plants and the ConAgra plant were much 

lower than those measured in the mixing room 

of the index plant (38 ppm in the index plant vs. 

approximately 1 ppm or less in the other plants) 

suggests that mixers may be at risk from brief, 

intense exposures during open handling of

flavorings and looking into tanks of heated oil 

and flavorings, even when ventilation maintains 

low average air concentrations of flavoring

chemicals. 

Microwave popcorn packaging-lines: During 

the March 2003 survey, NIOSH found that the 

slurry room was under negative air pressure

relative to the adjacent packaging area, a likely 

result of modifications to the slurry room

ventilation system which ConAgra performed 

after the January 2003 NIOSH visit. This

decreased the potential for slurry room

emissions to contaminate the packaging area, as 

evidenced by the much lower diacetyl air

concentrations NIOSH found in the packaging

area as compared to the slurry room in March

2003. However, the ventilation in the slurry 

room prior to these changes allowed flavoring 

chemicals in the air of the slurry room to move

into the air of the packaging area. Therefore, the 

March 2003 diacetyl air concentrations in the 

packaging area may underestimate past

exposures. Higher exposures in the past may 

explain the greater than expected numbers of

packaging-line workers reporting wheezing 

apart from colds and being told by a physician 

that they have asthma, and the high percentages 

of packaging-line workers reporting eye and

nasal irritation. Nine packaging-line workers 

had obstruction on NIOSH spirometry tests.

Five of them had no response to bronchodilator, 

had normal diffusing capacity, and had no

history of ever having worked as mixers. 

Although they were all smokers, their average 

age was 36 and none were over age 50, making 

it unlikely that all five had smoking-related 

disease. It is possible that some packaging-line

workers may have decreased lung function due 

to inhalation of flavoring chemicals originating 

in the slurry room. 

QA lab: Two of 11 current QA workers were 

found to have abnormal spirometry. One had

obstruction that was unresponsive to

bronchodilator and had a normal diffusing

capacity. Another had restriction. Several 

current QA workers reported respiratory

symptoms, as well as nasal and eye irritation. At 

the index plant where flavorings-related lung

disease in microwave popcorn workers was first 

identified, five of six QA workers that popped 

approximately 100 bags of microwave popcorn 

in microwave ovens per work shift per worker 

were found to have fixed obstruction. The 

average diacetyl air concentration in the QA lab 

at the index plant was higher than in the QA lab 

at the ConAgra plant (0.56 ppm vs. 0.018 ppm). 

Despite this lower average exposure, ConAgra 
Health Hazard Evaluation Report No. 2003-0112-2949 Page 11

QA lab workers may be at risk from the repeated 

brief, intense exposures that occur with the

popping of up to 130 bags per worker per 12-

hour shift. 

Press area: The press area had greater than

expected numbers of workers reporting

wheezing apart from colds and chronic 

bronchitis, and with obstruction on spirometry 

testing. Although the number of workers with 

obstruction was small and the excess was not 

statistically significant (four workers with

obstruction compared to two expected, after

adjusting for age, smoking history, race, and

gender), the excess obstruction in these workers 

is concerning given their potential for exposure 

to volatile chemicals used in the press area. All

the workers with obstruction were smokers. 

However, all were less than 50 years old

(average age 43), making it less likely that all 

had smoking-related disease. 

Sixty percent of survey participants reported

currently smoking cigarettes. This is higher than 

the average for any industry or occupation

surveyed and listed in the 2002 Work-Related 

Lung Disease Surveillance Report published by 

NIOSH.21This high smoking prevalence is not 

likely to explain all workers with obstruction in 

this plant, as obstructive lung disease in smokers 

typically does not occur before 45 years of age. 

However, as they age, smokers are at risk for 

many different smoking-related diseases,

including obstructive lung disease, lung and

other cancers, heart disease, and stroke. Nearly 

half a million Americans die each year from

smoking-related diseases. Workers who smoke

should seriously consider these potential health 

effects and commit to stop smoking. Options for 

workers who would like to stop smoking 

include company-sponsored smoking cessation

programs, programs available through the

American Lung Association and other similar 

organizations (many of which are free), and

recommendations from personal physicians. 

CONCLUSIONS

Findings from a NIOSH medical and

environmental evaluation at the ConAgra Snack 

Foods microwave popcorn plant in Marion,

Ohio, and from similar evaluations at the plants 

of several other companies, indicate that

production workers are at risk for lung disease 

from inhalation of butter flavoring-related 

chemicals. Maintaining low average exposures

through the use of ventilation may not eliminate 

risk if brief, intense exposures are still possible . 

Intense exposures can occur when workers

manually measure or mix quantities of

flavorings, look into open tanks of heated oil and 

flavorings, clean up flavoring spills, or pop

many dozens of bags of product in microwave 

ovens per work shift. Packaging-line workers 

may be at risk when exposed to emissions from 

nearby flavoring mixing activities and nonisolated tanks of oil and/or flavorings. To 

minimize the risk of lung disease and other

health effects in workers exposed to flavoringrelated chemicals, ConAgra should minimize

worker exposures (including brief, intense

exposures) to the greatest extent possible , and 

monitor potentially exposed workers with

regularly scheduled spirometry to make sure that 

exposure control interventions are effective at 

preventing effects on lung function. 

RECOMMENDATIONS

NIOSH provided the following

recommendations to ConAgra in its October

2003 interim report. (The information presented 

as “Follow-up” refers to NIOSH observations 

during a walkthrough of the plant on September 

2, 2004, and to information provided by

ConAgra during, or shortly after, that visit.)

1. Identify and implement engineering

changes that allow flavorings to be

added to heated oil in a closed system 

(i.e., no worker exposures to open

containers of flavorings) and eliminate 

the need for workers to look into open 

tanks of heated oil and flavorings. A 

closed system requires that all aspects of 

the mixing process be tightly contained 

(e.g., all tanks should have lids that seal 

tightly and prevent the escape of vapors 

into the air). Alternatively, some

powdered flavorings (e.g., encapsulated 

flavorings) minimize the release of

volatile flavoring chemicals into the air 
Page 12 Health Hazard Evaluation Report No. 2003-0112-2949

and may be a safer alternative to liquid 

and paste flavorings when handled in

open containers. However, some

powdered flavorings generate significant 

amounts of airborne dust when handled 

which may be harmful if inhaled. 

Require the use of appropriate

respirators (see below) by workers

handling open containers of flavorings 

of any type. (Follow-up: ConAgra 

management reported that it was

currently reviewing consultant 

recommendations for implementing a

closed process for flavor handling.)

2. Until a closed system for mixing of oil 

and flavoring is implemented, assure

that ventilation minimizes worker

exposures as much as possible. All

production areas should have adequate 

general dilution ventilation. Maintain 

the slurry room under negative airpressure relative to the rest of the plant, 

and exhaust the air from this room out 

of the plant. If not already done, install 

a local exhaust hood over the area where 

mixers weigh and measure amounts of 

flavorings, and implement local exhaust 

ventilation to all tanks that contain

heated oil and flavorings. Regularly

check and maintain all ventilation

systems to assure adequate function and 

prevent breakdowns. (Follow-up:

Testing with smoke tubes showed that 

the slurry room was under negative air 

pressure relative to the packaging area. 

NIOSH noted that an air pressure

monitor and alarm had been installed. 

(The same observations were made

regarding the QA lab.) The table in the 

slurry room where workers weigh

flavorings in open containers had local 

exhaust ventilation. Testing with smoke 

tubes showed this local exhaust

ventilation to be effective up to several 

feet away from the exhaust point. 

ConAgra management reported that

local exhaust ventilation for the heated 

tanks had not been installed because the 

tanks had tight fitting lids and because 

of concern that some of the liquid

contents might be sucked into the

ventilation duct when the tanks were

full.)

3. Perform regularly-scheduled air

sampling for flavoring-related ketone

compounds such as diacetyl to ensure 

the effectiveness of control

interventions. (Follow-up: ConAgra

management reported that the results of 

air sampling performed for the company 

by a consultant were similar to the

results obtained by NIOSH.)

4. Assure that the slurry room remains

closed off from the packaging area at all 

times. This may require the installation 

of an enclosure / air-lock system with an 

additional door(s) in front of the current 

doors. In this way, workers can enter 

the enclosure and close the outer door(s) 

before opening any of the current slurry 

room doors. (Follow-up: The slurry 

room door was closed. ConAgra

management reported that it was not

able to install the additional door for the 

slurry room due to insufficient space.)

5. Continue to require mandatory

respirator use by mixers and any other 

workers who enter the slurry room, as 

part of a formal respiratory protection 

program that adheres to the

requirements of the OSHA Respiratory

Protection Standard (29 CFR 1910.134). 

Workers require medical clearance for 

respirator use, fit testing of the respirator 

they will use before they are allowed to 

use it, and training on the hazards they 

are exposed to and on how to wear and 

maintain their respirator. The

administrator that you select for the

program must have adequate training or 

experience to run it and regularly

evaluate its effectiveness. Details on the 

Respiratory Protection Standard and on 

how a company can set up a respiratory 

protection program are available on the 

OSHA website (www.osha.gov). The

minimum protective respirator that

NIOSH recommends is a NIOSHcertified half-facepiece negativepressure respirator with organic vapor 
Health Hazard Evaluation Report No. 2003-0112-2949 Page 13

cartridges and particulate filters. A fullfacepiece respirator would provide eye 

protection as well. A loose-fitting 

powered air-purifying respirator with a 

particulate filter and organic vapor

cartridge is an option to consider for 

increased worker comfort and does not 

require fit testing. Another option is a 

supplied-air respirator. Require that

mixers and other workers wear their

respirators whenever they are in the

slurry room at any time and for any 

reason. (Follow-up: According to

workers and company management, 

ConAgra implemented mandatory use of 

powered air-purifying respirators for all 

workers that enter the slurry room

shortly after the NIOSH survey in

March, 2003. ConAgra management

provided a copy of their respiratory

protection program. A storage area with 

lockers to store workers’ respirators, and 

a battery charge station, were located

near the slurry room. A worker in the 

slurry room was seen using a powered 

air-purifying respirator during the

September 2004 NIOSH visit.)

6. Enclose and implement local exhaust

ventilation for microwave ovens in the 

QA lab to prevent air inside the ovens 

from blowing toward the QA worker. 

Instruct QA workers to allow popped 

bags to cool before opening them and to 

open them inside of the enclosure. 

Include these workers in the respiratory 

protection program and require that they 

use a respirator (from the choices above) 

until the enclosures and ventilation are 

in place and follow-up spirometry

testing shows that their lung function is 

remaining stable. (Follow-up: All

microwave ovens were located in a

hood-type enclosure with local exhaust 

ventilation. After popping microwave 

popcorn in the ovens, the QA lab worker 

opened the bags of popcorn outside of 

the hood after the bags had cooled

somewhat. Management informed 

NIOSH that the worker could not open 

the bags in the hood because the sliding 

panel for the hood opening would have 

to be in the raised (open) position,

which would allow gases to escape from 

the hood if additional bags of popcorn 

were being popped in the ovens. 

Waiting to start the ovens to pop

additional bags might mean that the

worker could not accomplish all the QA 

popping that is usually done during the 

work shift. Follow-up 

recommendation: Install local exhaust 

for the area where the bags are opened if 

the worker is not able to wait until the 

bags have cooled before opening them.) 

7. Implement a spirometry testing program 

as described in Appendix D for QA

workers, mixers, and any other workers 

that enter the slurry room. (Follow-up:

A review of worker tests performed by 

ConAgra’s provider showed that the

quality of the tests was not good enough 

to allow a comparison of workers’ test 

results over time. Follow-up 

recommendation: Discuss with the 

spirometry provider the importance of 

following the American Thoracic

Society guidelines for standardization of 

spirometry.10 All tests must have at least 

three acceptable maneuvers. Additional 

maneuvers may be necessary in order to 

obtain measurements that are

reproducible. (The two largest FVC and

FEV1 measurements should differ by

less than 200 milliliters). The 

spirometry technicians should attend a 

NIOSH-certified spirometry course and 

demonstrate knowledge of proper 

techniques for coaching test subjects. 

8. Evaluate the processes and exposures in 

the press area to minimize any

potentially harmful exposures that press 

workers may experience. NIOSH can

perform this as part of this HHE or a 

separate HHE requested by company

management and/or workers. 

Alternatively, ConAgra can arrange to 

have this done by private occupational 

health and safety consultants. (Followup: ConAgra management reported that 

its evaluation of the press area did not 
Page 14 Health Hazard Evaluation Report No. 2003-0112-2949

reveal any exposures that exceeded

established standards.)

9. Establish a smoking cessation program 

and encourage workers to utilize it.

(Follow-up: ConAgra management

reported that it was providing interested 

workers with referrals to a smoking

cessation program.)

REFERENCES

1. Kreiss K, Gomaa A, Kullman G, et al. [2002]. 

Clinical bronchiolitis obliterans in workers at a 

microwave-popcorn plant. N Engl J Med 347 

(5):330-338.

2. Hubbs AF, Batelli LA, Goldsmith WT, et al. 

[2002]. Necrosis of nasal and airway epithelium 

in rats inhaling vapors of artificial butter

flavoring. Toxicol Appl Pharmacol 185:128-

135.

3. King TE [1998]. Bronchiolitis. In: Fishman 

AP, ed. Fishman’s pulmonary diseases and

disorders. New York, NY: McGraw-Hill, pp. 

825-847.

4. Akpinar-Elci M, Travis WD, Lynch DA,

Kreiss K [2004]. Bronchiolitis obliterans

syndrome in popcorn plant workers. Eur Resp J 

24: 298-302.

5. Kanwal R [2003]. Letter of May 13, 2003, 

from R. Kanwal and S. Martin, Division of 

Respiratory Disease Studies, National Institute 

for Occupational Safety and Health, Centers for 

Disease Control and Prevention, Department of 

Health and Human Services, to Keith

Heuermann, B. K. Heuermann Popcorn, Inc., 

Phillips, Nebraska.

6. NIOSH [2004]. Hazard Evaluation and

Technical Assistance Report: American Pop

Corn Company, Sioux City, Iowa. Cincinnati, 

OH: U.S. Department of Health and Human

Services, Public Health Service, Centers for

Disease Control and Prevention, National

Institute for Occupational Safety and Health,

DHHS (NIOSH) Publication No. 2001-0474-

2943.

7. NIOSH [2003]. Hazard Evaluation and

Technical Assistance Report: Agrilink Foods 

Popcorn Plant, Ridgway, Illinois. Cincinnati,

OH: U.S. Department of Health and Human

Services, Public Health Service, Centers for

Disease Control and Prevention, National

Institute for Occupational Safety and Health,

DHHS (NIOSH) Publication No. 2002-0408-

2915.

8. Ferris BG [1978]. Epidemiology 

standardization project. Am Rev Respir Dis 

118:Suppl:1-53. 

9. CDC [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, Public Health 

Service, CDC. (Public use data file 

documentation No. 76300.)

10. American Thoracic Society [1995].

Standardization of spirometry: 1994 update. Am 

J Respir Crit Care Med 152:1107-1136. 

11. Hankinson JL, Odencrantz JR, Fedan KB 

[1999]. Spirometric reference values from a 

sample of the general U.S. population. Am J 

Resp Crit Care Med 159:179-187.

12. American Thoracic Society. Single -breath 

carbon monoxide diffusing capacity:

recommendations for a standard technique -

1995 update. Am J Respir Crit Care Med 1995; 

152:2185-2198.

13. Miller A, Thornton JC, Warshaw R, et al. 

Single-breath diffusing capacity in a

representative sample of the population of

Michigan, a large industrial state. Am Rev

Respir Dis 1983; 127:270-277.

14. Kahn H, Sempos C [1989]. Statistical

methods in epidemiology. Oxford University 

Press, pp 100-101.
Health Hazard Evaluation Report No. 2003-0112-2949 Page 15

15. NIOSH [1994]. NIOSH Manual of

Analytical Methods (4th edition). Washington, 

DC: U.S. Department of Health and Human

Services, Public Health Service, Centers for

Disease Control and Prevention, National

Institute for Occupational Safety and Health.

Publication No. 94-113.

16. Boehler A , Estenne M [2003]. Posttransplant bronchiolitis obliterans. Eur Resp J

22:1007-1018.

17. Lockey J, McKay R, Barth E, et al. [2002]. 

Bronchiolitis obliterans in the food flavoring

manufacturing industry [Abstract]. Am J Respir 

Crit Care Med 165:Suppl:A461. 

18. NIOSH [1986]. Health hazard evaluation 

and technical assistance report: International

Bakers Services, Inc., South Bend, Indiana.

Cincinnati, OH: U.S. Department of Health and 

Human Services, Public Health Service, Centers 

for Disease Control, National Institute for

Occupational Safety and Health, DHHS

(NIOSH) Publication No. 85-171-1710. 

19. NIOSH [2004]. NIOSH Alert: Preventing 

lung disease in workers that use or make

flavorings, Division of Respiratory Disease

Studies, National Institute for Occupational

Safety and Health, Department of Health and 

Human Services, DHHS (NIOSH) Publication 

Number 2004-110.

20. Hubbs AF, Battelli LA, Mercer RR, Kashon 

M, Friend S, Schwegler-Berry D, Goldsmith WT 

[2004]. Inhalation toxicity of the flavoring

agent, diacetyl (2, 3-butanedione), in the upper 

respiratory tract of rats. Toxicol Sci 78 (S1):

438-439.

21. Work-Related Lung Disease Surveillance 

Report 2002 [2002]. Division of Respiratory 

Disease Studies, National Institute for 

Occupational Safety and Health, Centers for 

Disease Control and Prevention, Department of 

Health and Human Services.
Page 16 Health Hazard Evaluation Report No. 2003-0112-2949

Table 1. Survey participation and characteristics of participants by current work area

Work Area Total 

Workers*

Survey 

Participants 

(N)

% 

Participation

Mean Age 

(Years)

Males

n (%)

Current or 

Former 

Smokers

n (%)

Press 40 28 70 37.3 26 (93) 22 (79)

Slurry Room 12 12 100 31.6 12 (100) 8 (67)

Packaging 155 110 71 34.1 69 (63) 82 (75)

QA 13 11 85 40.5 2 (18) 10 (91)

Warehouse 30 8 27 37.1 6 (75) 7 (88)

Office 29 10 34 39.1 3 (30) 5 (50)

Maintenance 34 26 76 42.1 25 (96) 14 (54)

Totals 313 205 65 36.1 143 (70) 148 (72)

*Totals as reported by Tony Jones, plant manager, at January 8, 2003 meeting

Table 2. Symptoms by current work area

Symptoms* Packaging

N=110

n (%)

Slurry

N=12

n (%)

QA

N=11

n (%)

Press

N=32

n (%)

All Others

N=40

n (%)

Trouble breathing during last 

12 months

27 (25) 4 (33) 3 (27) 8 (25) 10 (25)

SOB** hurrying or slight hill

SOB** walking with people 

same age on level ground 

24 (22)

6 (6)

4 (33)

0

4 (36)

3 (27)

6 (19)

4 (13)

10 (25)

3 (8)

Usual cough 35 (32) 3 (25) 4 (36) 9 (28) 7 (18)

Chronic cough (on most days 

for 3 consecutive months)

14 (13) 1 (8) 2 (18) 5 (16) 3 (8)

Wheezing apart from cold 30 (27) 6 (50) 4 (36) 8 (25) 8 (20)

Fever/chills/sweats 16 (15) 1 (8) 3 (27) 4 (13) 1 (3)

Unusual fatigue 25 (23) 4 (33) 4 (36) 4 (13) 5 (13)

Nasal irritation 69 (63) 10 (83) 6 (55) 13 (41) 17 (43)

Nose bleeds 9 (8) 3 (25) 2 (18) 2 (6) 1 (3)

Coughed up blood 9 (8) 1 (8) 1 (9) 1 (3) 1 (3)

Eye irritation 44 (40) 4 (33) 5 (45) 13 (41) 11 (28)

Skin problems 25 (23) 2 (17) 1 (9) 11 (34) 4 (10)

*See Appendix A for text of questions on questionnaire

**SOB=Shortness of breath

N= number of participants from work area

n= number of participants that reported symptom
Health Hazard Evaluation Report No. 2003-0112-2949 Page 17

Table 3. Abnormalities on NIOSH tests and worker-reported respiratory diagnoses by current 

work area

Lung Function Test Results

Packaging

N=110

n (%)

Slurry Room

N=12

n (%)

QA

N=11

n (%)

Press

N=32

n (%)

All others

N=40

n (%)

Abnormal Spirometry

--obstruction or mixed pattern

--restriction

14 (13)

9 (8)

5 (5)

4 (33)

3 (25)

1 (8)

2 (18)

1 (9)

1 (9)

6 (19)

4 (13)

2 (6)

3 (8)

2 (5)

1 (3)

+ Bronchodilator Response 1 of 9 1 of 3 0 of 1 1 of 4 1 of 2

Abnormal Diffusing Capacity 6 of 14 1 of 4 0 of 2 2 of 6 1 of 3

Respiratory Diagnoses

Bronchitis while working in 

plant*

13 (12) 4 (33) 4 (36) 5 (16) 0

Chronic Bronchitis* 8 (7) 0 1 (9) 5 (16) 3 (8)

Pneumonia while in plant* 7 (6) 0 0 1 (3) 0

Asthma* 18 (16) 2 (17) 2 (18) 3 (9) 5 (13)

Pneumothorax (Collapsed 

lung)*

2 (2) 0 0 3 (9) 0

*See appendix A for text of questions on questionnaire

N= number of participants from work area

n= number of participants with abnormality or reporting diagnosis
Page 18 Health Hazard Evaluation Report No. 2003-0112-2949

Table 4. Numbers of packaging area workers reporting respiratory symptoms and physiciandiagnosed respiratory disease, and with abnormal spirometry test results, compared to the 

numbers expected from NHANES III (adjusted for age, sex, race, and smoking status)

Condition Participants # Obs a# Expb O/E (95% CI)c

Shortness of breath when hurrying on the 

level or walking up a slight hill

 < 40 years

 = 40 years

 Total

80

30

110

15

9

24

15.2

7.6

22.8

1.0 (0.6-1.6)

1.2 (0.6-2.2)

1.1 (0.7-1.6)

Wheezing aside from a cold

 < 40 years

 = 40 years

 Total

80

30

110

28

6

34

11.8

4.0

15.9

2.4 (1.6-3.4)†

1.5 (0.7-3.2)

2.1 (1.5-3.0)†

Chronic coughd

 < 40 years

 = 40 years

 Total

80

30

110

10

4

14

9.0

3.5

12.5

1.1 (0.6-2.0)

1.2 (0.4-3.0)

1.1 (0.7-1.9)

Chronic bronchitis confirmed by MD

 < 40 years

 = 40 years

 Total

80

30

110

7

1

8

4.6

2.0

6.6

1.5 (0.7-3.2)

0.5 (0.1-2.8)

1.2 (0.6-2.4)

Asthma confirmed by MD

 < 40 years

 = 40 years

 Total

80

30

110

16

2

18

6.9

2.4

9.3

2.3 (1.4-3.8)†

0.8 (0.2-3.1)

1.9 (1.2-3.1)†

Obstruction or mixed pattern

 < 40 years

 = 40 years

 Total

80

30

110

5

4

9

2.9

2.8

5.8

1.7 (0.7-4.0)

1.4 (0.6-3.6)

1.6 (0.8-3.0)

Restriction

 < 40 years

 = 40 years

 Total

80

30

110

3

2

5

4.6

2.7

7.4

0.6 (0.2-1.9)

0.7 (0.2-2.7)

0.7 (0.3-1.6)

a

number observed bnumber expected 

c

observed/expected (95% confidence interval)

dUsually cough on most days for 3 consecutive months or more during the year

† Statistically significant (confidence interval (CI) does not include 1)
Health Hazard Evaluation Report No. 2003-0112-2949 Page 19

Table 5. Numbers of slurry room and QA workers reporting respiratory symptoms and physiciandiagnosed respiratory disease, and with abnormal spirometry test results, compared to the 

numbers expected from NHANES III (adjusted for age, sex, race, and smoking status)

Condition Participants # Obs a# Expb O/E (95% CI)c

Shortness of breath when hurrying on the 

level or walking up a slight hill

 < 40 years

 = 40 years

 Total

14

9

23

5

3

8

2.4

2.8

5.1

2.1 (0.9-4.9)

1.1 (0.4-3.2)

1.6 (0.8-3.1)

Wheezing aside from a cold

 < 40 years

 = 40 years

 Total

14

9

23

7

3

10

1.9

1.5

3.3

3.7 (1.8-7.7)†

2.0 (0.7-6.0)

3.0 (1.6-5.5)†

Chronic coughd

 < 40 years

 = 40 years

 Total

14

9

23

0

3

3

1.5

1.3

2.7

0.0 (0.0-2.6)

2.3 (0.8-6.9)

1.1 (0.4-3.2)

Chronic bronchitis confirmed by MD

 < 40 years

 = 40 years

 Total

14

9

23

0

1

1

0.7

0.8

1.6

0.0 (0.0-5.2)

1.2 (0.2-6.7)

0.6 (0.1-3.6)

Asthma confirmed by MD

 < 40 years

 = 40 years

 Total

14

9

23

2

2

4

1.2

0.8

2.0

1.7 (0.5-6.3)

2.5 (0.7-9.1)

2.1 (0.8-5.3)

Obstruction or mixed pattern

 < 40 years

 = 40 years

 Total

14

9

23

1

3

4

0.5

1.1

1.6

2.2 (0.4-12.3)

2.7 (0.9-7.8)

2.5 (1.0-6.5)

Restriction

 < 40 years

 = 40 years

 Total

14

9

23

1

1

2

0.8

0.9

1.7

1.3 (0.2-7.3)

1.1 (0.2-6.4)

1.2 (0.3-4.4)

a

number observed bnumber expected cobserved/expected (95% confidence interval)

dUsually cough on most days for 3 consecutive months or more during the year

† Statistically significant (confidence interval (CI) does not include 1)
Page 20 Health Hazard Evaluation Report No. 2003-0112-2949

Table 6. Numbers of press area workers reporting respiratory symptoms and physician-diagnosed 

respiratory disease, and with abnormal spirometry test results, compared to the numbers expected 

from NHANES III (adjusted for age, sex, race, and smoking status)

Condition Participants # Obs a# Expb O/E (95% CI)c

Shortness of breath when hurrying on the 

level or walking up a slight hill

 < 40 years

 = 40 years

 Total

18

14

32

2

4

6

3.1

3.6

6.7

0.7 (0.2-2.4)

1.1 (0.4-2.8)

0.9 (0.4-2.0)

Wheezing aside from a cold

 < 40 years

 = 40 years

 Total

18

14

32

4

5

9

2.7

2.1

4.8

1.5 (0.6-3.8)

2.3 (1.0-5.5)†

1.9 (1.0-3.6)

Chronic coughd

 < 40 years

 = 40 years

 Total

18

14

32

1

4

5

2.0

1.9

3.9

0.5 (0.1-2.9)

2.1 (0.8-5.4)

1.3 (0.6-3.0)

Chronic bronchitis confirmed by MD

 < 40 years

 = 40 years

 Total

18

14

32

2

3

5

0.6

0.9

1.5

3.5 (1.0-12.8)

3.2 (1.1-9.4)†

3.3 (1.4-7.7)†

Asthma confirmed by MD

 < 40 years

 = 40 years

 Total

18

14

32

0

3

3

1.5

1.1

2.6

0.0 (0.0-2.5)

2.8 (1.0-8.2)

1.2 (0.4-3.4)

Obstruction or mixed pattern

 < 40 years

 = 40 years

 Total

18

14

32

0

4

4

0.8

1.5

2.2

0.0 (0.0-5.0)

2.7 (1.1-7.0)†

1.8 (0.7-4.6)

Restriction

 < 40 years

 = 40 years

 Total

18

14

32

1

1

2

1.2

1.3

2.5

0.9 (0.2-4.9)

0.7 (0.1-4.2)

0.8 (0.2-2.9)

a

number observed bnumber expected cobserved/expected (95% confidence interval)

dUsually cough on most days for 3 consecutive months or more during the year

†Statistically significant (confidence interval (CI) does not include 1)
Health Hazard Evaluation Report No. 2003-0112-2949 Page 21

Table 7. Summary of predominant volatile organic compounds identified in different plant areas

Slurry 

Room

Phaser 

Operator

Palletizer 

Operator

Fork Lift 

Operator

QA Warehouse Press 

Room

Office 

Worker

Diacetyl (2,3-butanedione) v v v v v v v

Acetoin (3-hydroxy-2-butanone) v v

Propylene glycol v v

Acetoin oligimers v

Ethanol v v

Hexane v v v

Tetrahydrofuran (THF) v

Limonene v v v v v v v

Methanol/acetaldehyde v v v

Ethyl acetate v v

Toluene v v v v

Dipropylene glycol methyl ether 

isomers

v v

1-(2-methoxypropoxy)-2-propanol v v

Perchloroethylene v v

a-Pinene v v v

ß-Pinene v

Butanol/trace benzene v

Acetone v v v

Methyl acetate v

Methylene chloride v

Trichloroethylene v

Decamethylcyclopentasiloxane v
Page 22 Health Hazard Evaluation Report No. 2003-0112-2949

Table 8. Plant-wide mean, minimum, and maximum air concentrations for diacetyl, acetoin, total 

hydrocarbons, and acetaldehyde 

Analyte Samples Mean STD Min Max

Diacetyl - All Samples, ppm

 - Personal Samples, ppm

 - Area Samples, ppm

123

75

48

0.15

0.14

0.17

0.41

0.36

0.49

ND

ND

LOQ

2.7

2.0

2.7

Acetoin – All Samples, ppm 123 0.11 0.38 ND 2.8

Total Hydrocarbons*, Mg/m348 1.25 0.92 ND 5.53

Acetaldehyde, ppm 48 0.05 0.05 ND 0.17

ppm- parts per million parts air by volume; Mg/m3- milligrams per cubic meter of air; STD - standard 

deviation; ND - below the minimum detectable concentration in air, approximately 0.004 ppm for

diacetyl and acetoin. LOQ – below minimum quantifiable concentrations, approximately 0.01ppm.
Health Hazard Evaluation Report No. 2003-0112-2949 Page 23

Table 9. Personal ketone exposures in parts per million parts of air by volume (ppm).

Diacetyl Acetoin Job Titles

Number 

of 

Samples Average Range Average Range

Mixer 7 1.03 0.16-1.97 0.755 0.094-1.82

Supervisor 11 0.17 LOQ -1.03 0.14 ND-1.04

Press Room 

Operator

7 0.01 ND-0.03 0.01 ND-0.03

Phaser Operator 5 0.02 0.01-0.03 0.01 LOQ-0.02

Warehouse 

Worker 3 0.02 LOQ-0.03 LOQ All LOQ

Case Packer 7 0.02 LOQ -0.03 0.01 LOQ -0.02

Cartoner 7 0.02 LOQ -0.04 0.01 LOQ -0.02

Palletizer 5 0.02 LOQ -0.04 0.01 LOQ -0.01

Janitor 1 0.02 0.02 0.01 0.01

Line Sanitation 3 0.02 0.01-0.03 0.02 LOQ -0.02

QA Worker 5 0.03 LOQ -0.04 0.02 LOQ -0.03

Office Worker 3 0.02 0.02-0.03 0.01 LOQ -0.01

Fork Lift Operator 6 0.03 0.01-0.04 0.01 ND-0.01

Worked In Many 

Areas of Plant

2 0.004 ND- LOQ LOQ LOQ

NIOSH Industrial 

Hygienist

1 0.10 0.10 0.09 0.09

Other 3 0.02 0.01-0.02 0.01 LOQ -0.01

ppm- parts per million parts air by volume; ND - below the minimum detectable concentration in air, 

approximately 0.004 ppm for both diacetyl and acetoin. LOQ – below minimum quantifiable 

concentrations in air, approximately 0.01ppm for both diacetyl and acetoin.
Page 24 Health Hazard Evaluation Report No. 2003-0112-2949

Table 10. Area ketone air concentrations in parts per million parts of air by volume (ppm).

Diacetyl Acetoin Location Number of 

Samples

Average Range Average Range

Slurry Room 6 1.26 0.53-2.68 1.07 0.29-2.80

Supervisor Office 2 0.01 LOQ -0.02 0.01 LOQ-0.02

Press Area 4 LOQ All LOQ LOQ All LOQ

Phaser Area 5 0.02 LOQ -0.03 0.01 LOQ -0.02

Warehouse 4 0.03 0.02-0.04 LOQ ND-LOQ

Case Packing 

Area

3 0.02 LOQ -0.03 0.01 LOQ -0.02

Cartoner Area 6 0.02 LOQ -0.03 0.02 LOQ -0.02

Palletizer Area 4 0.03 LOQ -0.03 0.01 ND-0.01

QA Lab 6 0.01 LOQ -0.02 0.01 LOQ -0.02

Office 3 0.01 LOQ -0.02 LOQ ND- LOQ

Fork Lift 3 0.02 0.01-0.03 LOQ All LOQ

Outside 1 ND ND ND ND

Other 2 0.01 LOQ -0.02 0.01 LOQ -0.02

ppm- parts per million parts air by volume; ND - below the minimum detectable concentration in air, 

approximately 0.004 ppm for both diacetyl and acetoin. LOQ – below minimum quantifiable 

concentrations in air, approximately 0.01ppm for both diacetyl and acetoin.
Health Hazard Evaluation Report No. 2003-0112-2949 Page 25

Table 11. Total hydrocarbon area air concentrations in milligram per cubic meter (mg/m3).

Total Hydrocarbons*

Location Number of 

Samples

Average Range

Slurry Room 6 1.03 LOQ - 2.19

Supervisor Office 2 1.78 1.52-2.05

Press Room 4 1.90 LOQ - 2.60

Phaser Area 5 2.07 LOQ - 5.53

Warehouse 4 0.66 ND - 0.8

Case Packing 

Area

4 1.02 LOQ - 1.66

Cartoner Area 5 0.80 (LOQ) All LOQ

Palletizer Area 4 0.66 ND - 0.8

QA Lab 6 1.62 LOQ - 3.29

Office 3 0.90 ND - 1.68

Fork Lift 3 0.80 (LOQ) All LOQ

Maintenance 2 2.06 1.77 - 2.35

Outside 1 ND ND

* Total hydrocarbon concentrations excluding the ketones diacetyl, acetoin, and nonanone.

mg/m3- milligrams per cubic meter of air; ND - below the minimum detectable concentration in air, 

approximately 0.44 mg/m3. LOQ – below minimum quantifiable concentrations in air approximately 

1.6 mg/m3.
Page 26 Health Hazard Evaluation Report No. 2003-0112-2949

Table 12. Acetaldehyde area air concentrations in parts per million parts of air by volume (ppm).

Acetaldehyde Location Number of 

Samples

Average Range

Slurry Room 6 0.02 ND - 0.05

Supervisor Office 2 0.08 0.05 - 0.11

Press Room 4 0.13 0.07 - 0.17

Phaser Area 5 0.04 LOQ - 0.06

Warehouse 4 0.03 LOQ - 0.04

Case Packing 

Area

4 0.02 ND - 0.04

Cartoner Area 6 LOQ ND - LOQ 

Palletizer Area 4 0.03 LOQ - 0.04

QA Lab 5 0.12 0.10 - 0.14

Office 3 LOQ ND – LOQ

Fork Lift 3 LOQ All LOQ

Other 2 0.15 0.15 

Outside 1 ND ND

ppm- parts per million parts air by volume; ND - below the minimum detectable concentration in air, 

approximately 0.014 ppm. LOQ – below minimum quantifiable concentrations in air, approximately 

0.036 ppm.

Table 13. Area total and respirable dust concentrations (mg/m3) in air

Analyte Samples Mean STD Min Max

Total Dust 49 0.24 0.40 ND 1.74

Respirable Dust 49 0.09 0.15 ND 0.65

mg/m3- milligrams per cubic meter of air; STD - standard deviation; ND - below the minimum detectable 

concentration in air, approximately 0.014 mg/m3 for total dust and 0.01 mg/m3 for respirable dust.

Table 14. Spirometry findings, bronchodilator response, and DLCO results in selected lung diseases

Disease Spirometry Bronchodilator 

Response

DLCO

Asthma Obstruction Yes Normal

Emphysema Obstruction No Low

Bronchiolitis Obliterans Obstruction No Normal

Silicosis Restriction No Low
Health Hazard Evaluation Report No. 2003-0112-2949 Page 27

Figure 1. Diacetyl and acetoin concentrations by job location

0.001

0.01

0.1

1

10

Press Room Worker

Warehouse Worker

Mixer

Phaser Op

Case Packer

Cartoner

Palletizer

Quality Control Worker

Office Worker

Supervisor

ppm

Diacetyl Acetoin
Page 28 Health Hazard Evaluation Report No. 2003-0112-2949

Figure 2. Real-time diacetyl, acetoin, and nonanone concentrations from the slurry room by 

sampling date. concentrations in ppm

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

9:18 9:55 10:30 11:06 11:42 12:18 12:53 13:29 14:05 14:40 15:16 15:52 16:27 17:03 17:39 18:15 18:50

Time

PPM

Diacetyl

Acetoin

2-Nonanone

FTIR Analysis - March 3, 2003

Slurry Room

0.00

1.00

2.00

3.00

4.00

5.00

6.00

0:00:04 0:35:45 1:11:26 1:47:07 2:22:51 2:58:33 3:34:18 4:10:03 4:45:47 5:21:31 5:57:16 6:33:03 7:08:50

Time

PPM

Diacetyl

Acetoin

2-Nonanone

FTIR Analysis - March 4, 2003

Slurry Room
Health Hazard Evaluation Report No. 2003-0112-2949 Page 29

Figure 3. Diacetyl concentrations by sampling flow rate in the slurry room

0.1

1

0.02 lpm 0.15 lpm

 Samples by Flow Rate

ppm

Figure 4. Total and respirable dust concentrations by job location

0.001

0.01

0.1

1

10

Press Room

Warehouse

Slurry Room

Phaser

Case Packer

Cartoner

Palletizer

Quality Assurance

Office

Supervisor 

mg/m3

TOTAL DUST RESPIRABLE DUST
Page 30 Health Hazard Evaluation Report No. 2003-0112-2949

Figure 5. Real-time particle count data by size category from the slurry room on March 3, 2003. 

Concentrations in particles per cubic centimeter (particles / CC)

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

1.0E+08

8:38 9:50 11:02 12:14 13:26 14:38 15:50 17:02

Time

Particles / CC

 0.3-0.5μm

 0.5-1.0μm

 1.0-5.0μm

 5.0-10.0μm

 >10.0μm

Figure 6. Real-time particle count data by size category from the QA lab on March 4, 2004. 

Concentrations in particles per cubic centimeter (particles / CC)

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

9:15 10:27 11:39 12:51 14:03 15:15 16:27 17:39

Time

Particles / CC

0.3-0.5μm

0.5-1.0μm

1.0-5.0μm

5.0-10.0μm

>10.0μm
Health Hazard Evaluation Report No. 2003-0112-2949 Page 31

Figure 7. Real-time particle count data by size category from the packaging line area by the 

palletizer on March 5, 2003. Concentrations in particles per cubic centimeter (particles / CC)

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

8:19 10:43 13:07 15:31 17:55

Time

Particles / CC

0.3-0.5μm

0.5-1.0μm

1.0-5.0μm

5.0-10.0μm

>10.0μm
Page 32 Health Hazard Evaluation Report No. 2003-0112

APPENDIX A

January 28, 2003

 HETA 2003-0112

 Interim Report #1

James Montealegre

VP of Procurement, Product Development,

 Graphics, and Legal Services

ConAgra Foods Retail Products Company

Snack Foods Group

7700 France Avenue South, Suite 200

Edina, Minnesota 55435

Dear Mr. Montealegre:

Thank you very much for facilitating our initial visit and walkthrough of the ConAgra Snack Foods plant 

in Marion, Ohio, on January 8, 2003. We initiated this visit after receiving a confidential request from 

current workers for a health hazard evaluation regarding respiratory problems and exposures from

microwave popcorn production processes. We were able to accomplish our goals for the visit and look 

forward to working with you and other ConAgra staff to complete our evaluation. This letter describes 

our plans for a detailed medical and environmental survey to evaluate the risk for lung disease in plant 

workers and contains initial recommendations for actions that ConAgra should take to minimize the risks 

to workers from exposures to concentrated flavorings. These recommendations are based on what we 

have learned regarding the risks for lung disease in other microwave popcorn plants and our observations 

of work processes during the walkthrough at your plant.

NIOSH Evaluation of Lung Disease Risk in Microwave Popcorn Plants

As we discussed with you during our visit, the National Institute for Occupational Safety and Health’s 

(NIOSH) investigation of lung disease in microwave popcorn plant workers has revealed that inhalation 

exposure to concentrated butter flavoring chemicals can lead to lung disease under certain working 

conditions. At the plant in Missouri where this problem was first recognized, eight former workers (four 

mixers and four workers on the packaging lines) developed fixed obstructive lung disease consistent with 

the rare disease, bronchiolitis obliterans. The illness in four of these workers was severe enough that they 

were placed on lung transplant lists by their physicians. A survey by NIOSH of current workers at the 

Missouri plant showed that three times as many workers as expected had fixed obstruction on lung 

function tests. Increasing cumulative exposure to indicators of butter flavoring exposure was associated 

with increasing rates of abnormal lung function in these workers. Quality control workers (those who 

microwave approximately 100 bags of microwave popcorn per worker per eight hour shift) were also 

found to be at risk. NIOSH is conducting animal experiments to learn more about which components of 

concentrated butter flavorings have potential to cause lung toxicity. Experiments so far have shown that 

diacetyl alone can lead to toxic effects. The other chemic al components that may contribute to toxicity, 

and the levels of exposure that are considered safe, are still not known. Also not known is the relative 

safety of powdered flavorings compared to liquids or pastes. Powders that are formulated to have lower

emissions of volatile flavoring chemicals may pose lower risk. However, inhalation of airborne dust 

when handling these flavorings may increase worker risk for lung problems. 

In addition to the Missouri plant and ConAgra’s plant in Marion, Ohio, NIOSH is evaluating the risk for 

lung disease in four other microwave popcorn plants. In one of these plants, tanks containing heated oil 
Health Hazard Evaluation Report No. 2003-0112 Page 33

and flavorings were located near packaging lines in a large open space. Nearly three times as many 

workers as expected were found to have obstruction on lung function testing. In two other plants, mixers 

were identified as having fixed obstructive lung disease consistent with bronchiolitis obliterans, with 

onset of symptoms after starting work as mixers. One of these plants had mixing room air concentrations 

of diacetyl and acetoin (measured by NIOSH as indicators of exposure to butter flavoring chemicals) that 

were much lower than the levels first measured by NIOSH in the Missouri plant. This finding

emphasizes the fact that safe levels of exposure to concentrated butter flavoring chemicals are still not 

known. Short-term peak exposures while handling open containers of flavorings or looking into tanks 

containing heated oil and flavorings may pose risk for workers even when ventilation maintains low 

average air concentrations. 

During our walkthrough at the ConAgra plant in Marion, Ohio, we noted processes and conditions that 

are similar to those we have seen in other plants. These include open handling of concentrated butter 

flavorings by workers, visible airborne dust from workers measuring and pouring powdered flavorings 

into tanks of heated soybean oil, tanks with loose fitting lids and no local exhaust ventilation, and lack of 

respirator use by mixing room workers. We noted that the mixing room was under slight positive 

pressure relative to the adjacent packaging area. We observed popping of many bags of product in 

microwave ovens that lacked controls to prevent worker exposure to vapors produced during heating. We

were told that 136 bags are popped by one worker per 12 hour shift. 

In order to evaluate the risk for lung disease in your workers from exposures related to microwave 

popcorn production, we plan to conduct medical and environmental surveys at the plant. The medical 

survey will consist of confidential worker interviews administered by NIOSH staff and lung function 

testing by NIOSH technicians. Please give all plant workers a copy of the attached letter and a copy of 

the attached flyer, which describes the survey and explains what their participation will entail. For most 

workers, the questionnaire and lung function testing can be completed in 30 to 75 minutes. Worker 

participation is voluntary, but we would like as many workers as possible to participate in order to have 

representative data for subgroups of workers in different aspects of production. Workers who may have 

little exposure, such as office workers, should also participate so that their findings can be compared to 

those with higher exposures. We will mail workers their lung function test results to their home address 

three to four weeks after the survey. After data analyses are complete, we will prepare a detailed report 

describing our findings and recommendations.

 

As discussed with you during our initial visit, we will utilize a trailer (approximately 14 feet wide by 60 

feet long) to house our equipment and conduct testing on the plant grounds. Your maintenance manager, 

Mr. Emery Calloway, identified a location behind the plant building that he felt would accommodate the 

trailer. We would like to conduct the surveys from March 3rd through March 14th, 2003, Monday through 

Friday, from 3 pm to 11 pm. Normally we can test 3-6 workers at a time. We want to work with the 

plant supervisors to facilitate efficient testing with as little disruption of your production process as 

possible.

The environmental survey will include both personal and area sampling to quantify air contaminants. 

Personal sampling will be done for several different ketone compounds commonly associated with 

artificial butter flavoring including diacetyl, acetoin, and nonanone. This sampling will involve attaching 

a small sampling pump to the worker and operating it for most of the work shift. Area sampling will also 

be done to measure airborne concentrations of diacetyl, acetoin, nonanone, acetaldehyde, acetic acid, 

butyric acid, total volatile hydrocarbons, total dust, and respirable dust. The area samplers will be placed 

at set locations in the plant and operated throughout the work shift. As we discussed during the walkthrough, we would like to work with you so that we can coordinate these sampling efforts and be aware of 

production schedules and products ahead of the actual survey dates. 
Page 34 Health Hazard Evaluation Report No. 2003-0112

Recommendations

We recommend that ConAgra take the steps below to minimize potentially harmful exposures to its 

workers. These recommendations are based on our having observed high risk to mixers or quality control 

workers in other microwave popcorn plants, and the similarity of some processes and conditions in your 

plant to those in the other plants we have evaluated.

1. Slurry room: 

• Install a local exhaust hood to control exposures where the mixers measure and weigh flavorings. 

• Install local exhaust ventilation on any mix, hold, or return tanks that cannot be tightly sealed.

• Maintain the slurry room under negative pressure relative to the rest of the plant.

• Evaluate air flow patterns in the slurry room and, as needed, install a duct to deflect air (entering 

the room from ducts near the ceiling) downward toward the workers’ breathing zones. 

• Regularly check and maintain all ventilation systems to minimize the possibility of a malfunction. 

Perform periodic sampling for diacetyl to verify that the ventilation systems in use are

functioning optimally. 

• Institute mandatory respirator use for mixers and for any other workers that enter the slurry room 

as part of a formal respiratory protection program that adheres to the requirements of the OSHA 

Respiratory Protection Standard (29 CFR 1910.134). Workers require medical clearance for 

respirator use, fit testing on the respirator they will use before they are allowed to use it, and 

training on the hazards they are exposed to and on how to wear and maintain their respirator. 

You can get details on the Respiratory Protection Standard and on how your company can set up 

a respiratory protection program at the OSHA website (www.osha.gov). The minimum 

protective respirator that we recommend is a NIOSH-certified half face mask negative pressure 

respirator with organic vapor cartridges and particulate filters. A full facepiece respirator would 

provide additional eye protection. A loose-fitting powered air-purifying respirator with a 

particulate filter and organic vapor cartridge is an option to consider for increased worker comfort 

and does not require fit testing. Another option is a supplied-air respirator. Require that mixers 

and other workers wear their respirators whenever they are in the slurry room for any reason.

2. Quality control:

• Install local exhaust ventilation for the microwave ovens used by workers to pop many bags of 

product for quality control.

• Include quality control workers in your respiratory protection program and advise them to use a 

respirator for popping product (choose a respirator from the same options as for mixers), until 

local exhaust for the microwave ovens is installed and our medical survey is complete. If our 

survey shows that these workers are at risk for lung problems, you should require that they wear 

respirators until follow-up lung function testing shows that the local exhaust ventilation is 

preventing hazardous exposures. 

• Require that quality control workers wear a respirator whenever they enter the slurry room.
Health Hazard Evaluation Report No. 2003-0112 Page 35

ConAgra should also implement these recommendations at its other microwave popcorn plants. 

Thank you for your continued assistance and please feel free to call with any questions that you have.

Sincerely,

Richard Kanwal, MD, MPH

Medical Officer

Greg Kullman, PhD, CIH

Respiratory Disease Hazard Evaluation and

 Technical Assistance Program

Field Studies Branch

Division of Respiratory Studies

cc: Confidential requestors

 HETAB (Hartle)

 OSHA, Region 5

Enclosures
Page 36 Health Hazard Evaluation Report No. 2003-0112

APPENDIX B

Questionnaire Used by NIOSH During March 2003 Medical Survey at ConAgra Snack 

Foods, Marion, Ohio

Interviewer: ____________ Interview Date: __ __ / __ __ / __ __ __ __

 (Month) (Day) (Year)

Section I: Identification and Demographic Information

Name: ____________________________ ______________________ ____

(Last name) (First name) (MI)

Address:_______________________________________________________

(Number, Street, and/or Rural Route)

 _____________________ ______________ __________

 (City) (State) (Zip Code)

Home Telephone Number: ( ) _______ - __________

If you were to move, is there someone who would know how to contact you?

Name: ____________________________ ______________________ ____

(Last name) (First name) (MI)

Relationship to you:____________________

Address:_______________________________________________________

 (Number, Street, and/or Rural Route)

 _____________________ ______________ __________

(City) (State) (Zip Code)

Home Telephone Number: ( ) _______ - __________

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. Date of Birth: __ __ / __ __ / __ __ __ __

 (Month) (Day) (Year)

2. Sex: 1. ____ Male 2. ____ Female

3. Are you Spanish, Hispanic, or Latino? 1.____Yes 0.____No.

4. Select one or more of the following categories to describe your race:

1. ___ White 3. ___ Asian

2. ___ African-American or Black 4. ___ American Indian or Alaska Native

5. ___ Native Hawaiian or Other Pacific 

Islander
Health Hazard Evaluation Report No. 2003-0112 Page 37

Section II: Health Information

I’m going to ask you some questions about your health. The answer to many of these 

questions will be “Yes” or “No.” If you are in doubt about whether to answer “Yes” or 

“No,” then please answer “No.” 

5. During the last 12 months, have you had any trouble with

your breathing? 1.____Yes 0. ____No

IF YES:

a) Which of the following statements best describes your breathing?

1. ___ I only rarely have trouble with my breathing

2. ___ I have regular trouble with my breathing but it always gets completely better

3. ___ My breathing is never quite right

6. Are you troubled by shortness of breath when hurrying

on level ground or walking up a slight hill? 1. ___ Yes 0. ___ 

No

IF YES:

a) Do you get short of breath walking with people

of your own age on level ground? 1. ___ Yes 0. ___ No

 

b) Do you ever have to stop for breath when

walking at your own pace on level ground? 1. ___ Yes 0. ___ No

c) Do you ever have to stop for breath after walking about

100 yards (or after a few minutes) on level ground? 1. ___ Yes 0. ___ No

 

d) In what month and year did this breathlessness start? __ __ / __ __ __ __

(Month) (Year)
Page 38 Health Hazard Evaluation Report No. 2003-0112

7. Do you usually have a cough? 1. ___ Yes 0. ___ No

(Count cough with first smoke or on first going

out-of-doors. Exclude clearing of throat.)

IF YES:

a) Do you usually cough on most days for 3

consecutive months or more during the year? 1. ___ Yes 0. ___ No

b) In what month and year did this cough begin? __ __ / __ __ __ __

(Month) (Year)

8. Have you ever had wheezing or whistling in your chest? 1. ___ Yes 0. ___ No

IF YES:

a) Have you had this wheezing or whistling when you

did not have a cold? 1. ___ Yes 0. ___ No

b) In what month and year did this wheezing or

whistling begin? __ __ / __ __ __ __

(Month) (Year)

c) When you are away from this plant on days off

or on vacation, is this wheezing or whistling 1. ___ Better

2. ___ The same

3. ___ Worse

4. ___ N/A

d) During the last 12 months, have you had this 

wheezing or whistling in your chest when you

did not have a cold? 1. ___ Yes 0. ___ No
Health Hazard Evaluation Report No. 2003-0112 Page 39

9. Have you ever had to change your job, job duties, or

work area at this plant because of breathing

difficulties? 1. ___ Yes 0. ___ No

IF YES:

a) What month and year did you change your job, 

job duties, or work area? __ __ / __ __ __ __

(Month) (Year)

b) What was your job, job duties, and/or work area before the change?

Describe: ___________________________________________________________

c) How did your job, job duties, and/or work area differ after the change?

Describe:___________________________________________________________

d) Were your breathing problems after the change:

1. ___ Better

2. ___ The Same

3. ___ Worse

10. While working at this plant, have you had fever,

chills or night-sweats? 1. ___ Yes 0. ___ No

IF YES:

a) How often have you had the fever, chills, or night-sweats? 1. ___ Rarely

2. ___ Monthly

3. ___ Weekly

4. ___ Daily

11. While working at this plant, have you had unusual

tiredness or fatigue? 1. ___ Yes 0. ___ No

IF YES:

a) How often have you had the unusual tiredness or fatigue? 1. ___ Rarely

2. ___ Monthly

3. ___ Weekly

4. ___ Daily
Page 40 Health Hazard Evaluation Report No. 2003-0112

12. Since you began working at this plant, have you

ever had attacks of bronchitis? 1. ___ Yes 0. ___ No

IF YES:

a) Was it confirmed by a doctor? 1. ___ Yes 0. ___ No

b) While working at this plant, how many times

have you had bronchitis? ______ Times

13. Have you ever had chronic bronchitis? 1. ___ Yes 0. ___ No

IF YES:

a) Was it confirmed by a doctor? 1. ___ Yes 0. ___ No 

b) How old were you when it began? ______ Years old

14. Since you began working at this plant have youever 

had pneumonia? (Include bronchopneumonia) 1. ___ Yes 0. ___ No

15. Have you ever had asthma? 1. ___ Yes 0. ___ No

IF YES:

a) How old were you when it began? ______ Years old

b) Was it confirmed by a doctor? 1. ___ Yes 0. ___ No

c) Do you still have it? 1. ___ Yes 0. ___ No

16. Have you ever had a pneumothorax, which is a collapsed lung? 1. ___ Yes 0. ___ No
Health Hazard Evaluation Report No. 2003-0112 Page 41

17. Since working at this plant, have you had symptoms of

nasal irritation such as a stuffy or blocked nose, an itchy

nose, a stinging or burning nose, or a runny nose?

(apart from a cold) 1. ___ Yes 0. ___ No

IF YES:

a) Is there an exposure at work that aggravates 

these nose symptoms? 1. ___ Yes 0. ___ No

b) Describe exposure(s):

________________________________________________________________________

________________________________________________________________________

18. While working at this plant, have you had nose bleeds more 

than once a month? 1. ___ Yes 0. ___ No

19. While working at this plant, have you ever coughed up blood?1. ___ Yes 0. ___ No

20. Since working at this plant, have you had any symptoms of

eye irritation such as : watering or tearing eyes, red or 

burning eyes, itching eyes, dry eyes? 1. ___ Yes 0. ___ No

IF YES:

a) Is there an exposure at work that aggravates 

these eye symptoms? 1. ___ Yes 0. ___ No

b) Describe exposure(s):

________________________________________________________________________

________________________________________________________________________

21. Since working at this plant, have you developed

any new skin rash or skin problems? 1. ___ Yes 0. ___ No
Page 42 Health Hazard Evaluation Report No. 2003-0112

Section III. Work Information

I’m now going to ask you questions about your work history at this plant.

22. Have you ever worked as a mixer, even for as little as one day? 1. ___Yes 0. ___No

IF YES:

a) How long have you worked (or did you work) as a mixer? ______ Years

______ Months

______ Days

b) When mixing, how many hours per day do you (or did you)

spend in the slurry room? ______ hours/day

c) When mixing, do you (or did you) wear a respirator / dust mask while

handling powdered flavorings? ______ Yes, all of the time

______ Yes, some of the time

______ No

23. Have you ever worked as a mechanic? 1. ___Yes 0. ___No

IF YES:

a) How long have you worked (or did you work) as a mechanic? ______ Years

______ Months

______ Days

b) As a mechanic, how many hours per week

do you (or did you) spend in the slurry room? ______ hours/week

24. Have you ever spent time in the slurry room while doing 

any other job at this plant? (exclude work as a mixer or mechanic) 1. ___Yes 0 ___No

25. Have you ever worked in the QA lab (quality assurance) popping

bags in microwave ovens to check the product? 1. ___Yes 0. ___No

IF YES:

a) How long have you worked (or did you work) in the QA lab? ______ Years

______ Months

______ Days

b) When working in the QA lab, how many hours per day 

do you (or did you) spend in the QA lab? ______ hours/day

26. What is your usual work shift? _________________________________________

27. During an average work week, how many hours

do you work? ______ Hours per week
Health Hazard Evaluation Report No. 2003-0112 Page 43

28. Have you ever been exposed to a spill or unusual chemical 

release at work? 1.___ Yes 0.___ No

IF YES:

a) Did you have any symptoms from it? 1.___ Yes 0.___ No

IF YES:

b) What were your symptoms?

________________________________________________________________

29. Have you ever:

a) Worked in mining? 1. ___ Yes 0. ___ No IF YES: _____ Years

b) Worked in farming? 1. ___ Yes 0. ___ No IF YES: _____ Years

c) Worked in chemical manufacturing

like explosives, dyes, lacquers, and

celluloid? 1. ___ Yes 0. ___ No IF YES: _____ Years

d) Been exposed to fire smoke?

(Do not count campfires, stoves.) 1. ___ Yes 0. ___ No IF YES: _____ Years

e) Been exposed to irritant gases

like chlorine, sulfur dioxide,

ammonia, and phosgene? 1. ___ Yes 0. ___ No IF YES: _____ Years

f) Been exposed to mineral dusts

including coal, silica, and talc? 1. ___ Yes 0. ___ No IF YES: _____ Years

g) Been exposed to grain dusts? 1. ___ Yes 0. ___ No IF YES: _____ Years

h) Been exposed to oxides of

nitrogen including silo gas? 1. ___ Yes 0. ___ No IF YES: _____ Years

i) Been exposed to asbestos? 1. ___ Yes 0. ___ No IF YES: _____ Years

j) Been exposed to any chemical

or substance that affected your

breathing? 1. ___ Yes 0. ___ No

IF YES to Question j):

k) Describe the exposure:

___________________________________________________________________
Page 44 Health Hazard Evaluation Report No. 2003-0112

I’m now going to ask you some questions about all the jobs that you have had while at this plant. We will start with your current job 

and work back through time.

If Work Area is Press 

Room or Warehouse or 

Office

If Work Area is 

Maintenance

Job 

Number

Major

Work Area

Job

Title

Start Date

(MM/YYYY)

End Date

(MM/YYYY)

Hours/ Day Spent in 

Production

Hours/ week 

Spent in Slurry 

Room

Comments
Health Hazard Evaluation Report No. 2003-0112 Page 45

Section IV: Tobacco Use Information

I’m now going to ask you a few questions about tobacco use.

30. Have you ever smoked cigarettes? 1. ___ Yes 0. ___ No

(NO if less than 20 packs of cigarettes in a 

lifetime or less than 1 cigarette a day for 1 year.)

IF YES:

a) How old were you when you first started

smoking regularly? ______ Years old

b) Over the entire time that you have smoked,

what is the average number of cigarettes

that you smoked per day? ______ Cigarettes/day

c) Do you still smoke cigarettes? 1. ___ Yes 0. ___ No

IF NO:

d) How old were you when you stopped

smoking regularly? ______ Years old

Thank you for participating in this survey!
Page 46 Health Hazard Evaluation Report No. 2003-0112

APPENDIX C

Prevalence Ratios for Respiratory Symptoms, Self-Reported Respiratory Illness, and Abnormalities on NIOSH Spirometry Tests, as Reported in 

the October 2003 NIOSH Interim Report

Shortness of breath on exertion (ratios in bold are statistically significant)

Never Smokers Current and Former Smokers All Participants

Work area age group No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI)

Packaging 

17-39

40-69

Total

18

10

28

4

3

7

1.6

2.1

3.7

2.5 (1.0-6.4)

1.4 (0.5-4.2)

1.9 (0.9-3.9)

62

20

82

11

6

17

14.0

6.1

20.1

0.8 (0.4-1.4)

1.0 (0.5-2.2)

0.8 (0.5-1.4)

80

30

110

15

9

24

15.6

8.2

23.8

1.0 (0.6-1.6)

1.1 (0.6-2.1)

1.0 (0.7-1.5)

Slurry room and QA

17-39 

40-69

Total 

X

X

5

X

X

2

X

X

0.6

5.0 (1.4-18.2)

0.0 (0.0-19.2)

3.3 (0.9-12.2)

10

8

18

3

3

6

2.3

2.4

4.7

1.3 (0.4-3.8)

1.3 (0.4-3.7)

1.3 (0.6-2.8)

14

9

23

5

3

8

2.7

2.6

5.3

1.9 (0.8-4.3)

1.2 (0.4-3.4)

1.5 (0.8-3.0)

Press

17-39

40-69

Total

4

2

6

1

0

1

0.4

0.4

0.8

2.5 (0.4-14.2)

0.0 (0.0-9.6)

1.3 (0.2-7.1)

14

12

26

1

4

5

3.2

3.6

6.8

0.3 (0.1-1.8)

1.1 (0.4-2.9)

0.7 (0.3-1.7)

18

14

32

2

4

6

3.6

4.0

7.6

0.6 (0.2-2.0)

1.0 (0.4-2.6)

0.8 (0.4-1.7)

Exp =expected number, Obs =observed number, CI=confidence interval, X=data not shown in order to maintain confidentiality of participants 

Chronic cough (ratios in bold are statistically significant)

Never Smokers Current and Former Smokers All Participants

Work area age group No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI)

Packaging 

17-39

40-69

Total

18

10

28

0

1

1

0.4

0.6

1.0

0.0 (0.0-9.6)

1.7 (0.3-9.4)

1.0 (0.2-5.7)

62

20

82

10

3

13

8.1

2.9

11.0

1.2 (0.7-2.3)

1.0 (0.4-3.0)

1.2 (0.7-2.0)

80

30

110

10

4

14

8.5

3.5

12.0

1.2 (0.6-2.2)

1.1 (0.4-2.9)

1.2 (0.7-2.0)

Slurry room and QA

17-39 

40-69

Total 

X

X

5

X

X

0

0.1

0.1

0.2

0.0 (0.0-38.4)

0.0 (0.0-38.4)

0.0 (0.0-19.2)

10

8

18

0

3

3

1.3

1.1

2.4

0.0 (0.0-3.0)

2.7 (0.9-8.0)

1.3 (0.4-3.7)

14

9

23

0

3

3

1.4

1.2

2.6

0.0 (0.0-2.7)

2.5 (0.9-7.4)

1.2 (0.4-3.4)

Press

17-39

40-69

Total

4

2

6

0

0

0

0.1

0.1

0.2

0.0 (0.0-38.4)

0.0 (0.0-38.4)

0.0 (0.0-19.2)

14

12

26

1

4

5

1.8

1.7

3.5

0.6 (0.1-3.2)

2.4 (0.9-6.1)

1.4 (0.6-3.3)

18

14

32

1

4

5

1.9

1.8

3.7

0.5 (0.1-3.0)

2.2 (0.9-5.7)

1.4 (0.6-3.2)

Exp =expected number, Obs =observed number, CI=confidence interval, X=data not shown in order to maintain confidentiality of participants 
Health Hazard Evaluation Report No. 2003-0112 Page 47

Wheezing apart from colds (ratios in bold are statistically significant)

Never Smokers Current and Former Smokers All Participants

Work area age group No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI)

Packaging 

17-39

40-69

Total

18

10

28

2

1

3

1.1

0.8

1.9

1.8 (0.5-6.6)

1.3 (0.2-7.1)

1.6 (0.5-4.6)

62

20

82

22

5

27

10.1

3.3

13.4

2.2 (1.4-3.3)

1.5 (0.7-3.6)

2.0 (1.4-2.9)

80

30

110

24

6

30

11.2

4.1

15.3

2.1 (1.4-3.2)

1.5 (0.7-3.2)

2.0 (1.4-2.8)

Slurry room and QA

17-39 

40-69

Total 

X

X

5

X

X

2

X

X

0.3

10.0 (2.7-36.5)

0.0 (0.0-38.4)

6.7 (1.8-24.3)

10

8

18

5

3

8

1.6

1.3

2.9

3.1 (1.3-7.3)

2.3 (0.8-6.8)

2.8 (1.4-5.4)

14

9

23

7

3

10

1.8

1.4

3.2

3.9 (1.9-8.0)

2.1 (0.7-6.3)

3.1 (1.7-5.6)

Press

17-39

40-69

Total

4

2

6

0

0

0

0.2

0.2

0.4

0.0 (0.0-19.2)

0.0 (0.0-19.2)

0.0 (0.0-9.6)

14

12

26

4

4

8

2.3

2.0

4.3

1.7 (0.7-4.5)

2.0 (0.8-5.1)

1.9 (0.9-3.7)

18

14

32

4

4

8

2.5

2.2

4.7

1.6 (0.6-4.1)

1.8 (0.7-4.7)

1.7 (0.9-3.4)

Exp =expected number, Obs =observed number, CI=confidence interval, X=data not shown in order to maintain confidentiality of participants 

Asthma (ratios in bold are statistically significant)

Never Smokers Current and Former Smokers All Participants

Work area age group No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI)

Packaging 

17-39

40-69

Total

18

10

28

7

0

7

1.2

0.7

1.9

5.8 (2.8-12.0)

0.0 (0.0-5.5)

3.7 (1.8-7.6)

62

20

82

9

2

11

5.5

1.7

7.2

1.6 (0.9-3.1)

1.2 (0.3-4.3)

1.5 (0.9-2.7)

80

30

110

16

2

18

6.7

2.4

9.1

2.4 (1.5-3.9)

0.8 (0.2-3.0)

2.0 (1.3-3.1)

Slurry room and QA

17-39 

40-69

Total 

X

X

5

X

X

2

X

X

0.4

6.7 (1.8-24.3)

0.0 (0.0-38.4)

5.0 (1.4-18.2)

10

8

18

0

2

2

0.9

0.7

1.6

0.0 (0.0-4.3)

2.9 (0.8-10.4)

1.3 (0.3-4.6)

14

9

23

2

2

4

1.2

0.8

2.0

1.7 (0.5-6.1)

2.5 (0.7-9.1)

2.0 (0.8-5.1)

Press

17-39

40-69

Total

4

2

6

0

0

0

0.3

0.1

0.4

0.0 (0.0-12.2)

0.0 (0.0-38.4)

0.0 (0.0-9.6)

14

12

26

0

3

3

1.2

1.0

2.2

0.0 (0.0-3.2)

3.0 (1.0-8.8)

1.4 (0.5-4.0)

18

14

32

0

3

3

1.5

1.1

2.6

0.0 (0.0-2.6)

2.7 (0.9-8.0)

1.2 (0.4-3.4)

Exp =expected number, Obs =observed number, CI=confidence interval, X=data not shown in order to maintain confidentiality of participants 
Page 48 Health Hazard Evaluation Report No. 2003-0112

Chronic bronchitis (ratios in bold are statistically significant)

Never Smokers Current and Former Smokers All Participants

Work area age group No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI)

Packaging 

17-39

40-69

Total

18

10

28

2

0

2

0.5

0.6

1.1

4.0 (1.1-14.6)

0.0 (0.0-6.4)

1.8 (0.5-6.6)

62

20

82

5

1

6

7.3

2.1

9.4

0.7 (0.3-1.6)

0.5 (0.1-2.7)

0.6 (0.3-1.4)

80

30

110

7

1

8

7.8

2.7

10.5

0.9 (0.4-1.9)

0.4 (0.1-2.1)

0.8 (0.4-1.5)

Slurry room and QA

17-39 

40-69

Total 

X

X

5

X

X

0

0.1

0.1

0.2

0.0 (0.0-38.4)

0.0 (0.0-38.4)

0.0 (0.0-19.2)

10

8

18

0

1

1

1.2

0.8

2.0

0.0 (0.0-3.2)

1.3 (0.2-7.1)

0.5 (0.1-2.8)

14

9

23

0

1

1

1.3

0.9

2.2

0.0 (0.0-3.0)

1.1 (0.2-6.3)

0.5 (0.1-2.6)

Press

17-39

40-69

Total

4

2

6

0

0

0

0.1

0.1

0.2

0.0 (0.0-38.4)

0.0 (0.0-38.4)

0.0 (0.0-19.2)

14

12

26

2

3

5

1.7

1.3

3.0

1.2 (0.3-4.3)

2.3 (0.8-6.8)

1.7 (0.7-3.9)

18

14

32

2

3

5

1.8

1.4

3.2

1.1 (0.3-4.1)

2.1 (0.7-6.3)

1.6 (0.7-3.7)

Exp =e xpected number, Obs =observed number, CI=confidence interval, X=data not shown in order to maintain confidentiality of participants 

Spirometry abnormalities (ratios in bold are statistically significant)

Never Smokers Current and Former Smokers All Participants

Work area age group No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI)

Packaging 

17-39

40-69

Total

18

10

28

0

2

2

1.2

1.0

2.2

0.0 (0.0-3.2)

2.0 (0.6-7.3)

0.9 (0.3-3.3)

62

20

82

8

4

12

5.9

4.3

10.2

1.4 (0.7-2.7)

0.9 (0.4-2.4)

1.2 (0.7-2.1)

80

30

110

8

6

14

7.1

5.3

12.4

1.1 (0.6-2.2)

1.1 (0.5-2.5)

1.1 (0.7-1.9)

Slurry room and QA

17-39 

40-69

Total 

X

X

5

X

X

1

X

X

0.4

3.3 (0.6-18.9)

0.0 (0.0-38.4)

2.5 (0.4-14.2)

10

8

18

1

4

5

1.0

1.7

2.7

1.0 (0.2-5.7)

2.4 (0.9-6.1)

1.9 (0.8-4.3)

14

9

23

2

4

6

1.3

1.8

3.1

1.5 (0.4-5.6)

2.2 (0.9-5.7)

1.9 (0.9-4.2)

Press

17-39

40-69

Total

4

2

6

0

0

0

0.3

0.2

0.5

0.0 (0.0-12.8)

0.0 (0.0-19.2)

0.0 (0.0-7.7)

14

12

26

1

5

6

1.3

2.6

3.9

0.8 (0.1-4.4)

1.9 (0.8-4.5)

1.5 (0.7-3.4)

18

14

32

1

5

6

1.6

2.8

4.4

0.6 (0.1-3.5)

1.8 (0.8-4.2)

1.4 (0.6-3.0)

Exp =expected number, Obs =observed number, CI=confidence interval, X=data not shown in order to maintain confidentiality of participants 
Health Hazard Evaluation Report No. 2003-0112 Page 49

Obstruction or mixed pattern on spirometry (ratios in bold are statistically significant)

Never Smokers Current and Former Smokers All Participants

Work area age group No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI)

Packaging 

17-39

40-69

Total

18

10

28

0

0

0

0.4

0.3

0.7

0.0 (0.0-9.6)

0.0 (0.0-12.8)

0.0 (0.0-5.5)

62

20

82

5

4

9

2.4

2.4

4.8

2.1 (0.9-4.9)

1.7 (0.7-4.3)

1.9 (1.0-3.6)

80

30

110

5

4

9

2.8

2.7

5.5

1.8 (0.8-4.2)

1.5 (0.6-3.8)

1.6 (0.9-3.1)

Slurry room and QA

17-39 

40-69

Total 

X

X

5

X

X

1

X

X

0.1

10.0 (1.8-56.7)

0.0 (0.0-128.1)

10.0 (1.8-56.7)

10

8

18

0

3

3

0.4

1.0

1.4

0.0 (0.0-9.6)

3.0 (1.0-8.8)

2.1 (0.7-6.3)

14

9

23

1

3

4

0.5

1.0

1.5

2.0 (0.4-14.2)

2.9 (1.0-8.8)

2.6 (1.0-6.9)

Press

17-39

40-69

Total

4

2

6

0

0

0

0.1

0.1

0.2

0.0 (0.0-38.4)

0.0 (0.0-38.4)

0.0 (0.0-19.2)

14

12

26

0

4

4

0.5

1.5

2.0

0.0 (0.0-7.7)

2.7 (1.0-6.9)

2.0 (0.8-5.1)

18

14

32

0

4

4

0.6

1.6

2.2

0.0 (0.0-6.4)

2.5 (1.0-6.4)

1.8 (0.7-4.7)

Exp =expected number, Obs =observed number, CI=confidence interval, X=data not shown in order to maintain confidentiality of participants 

Restriction on spirometry (ratios in bold are statistically significant)

Never Smokers Current and Former Smokers All Participants

Work area age group No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI) No. Obs # Exp # Obs/Exp (CI)

Packaging 

17-39

40-69

Total

18

10

28

0

2

2

0.8

0.8

1.6

0.0 (0.0-4.8)

2.5 (0.7-9.1)

1.3 (0.3-4.6)

62

20

82

3

0

3

3.5

1.9

5.4

0.9 (0.3-2.5)

0.0 (0.1-3.0)

0.6 (0.2-1.6)

80

30

110

3

2

5

4.3

2.7

7.0

0.7 (0.2-2.1)

0.7 (0.2-2.7)

0.7 (0.3-1.7)

Slurry room and QA

17-39 

40-69

Total 

X

X

5

X

X

0

0.2

0.1

0.3

0.0 (0.0-19.2)

0.0 (0.0-38.4)

0.0 (0.0-12.8)

10

8

18

1

1

2

0.6

0.8

1.4

1.7 (0.3-9.4)

1.3 (0.2-7.1)

1.4 (0.4-5.2)

14

9

23

1

1

2

0.8

0.9

1.7

1.3 (0.2-7.1)

1.1 (0.2-6.3)

1.2 (0.3-4.3)

Press

17-39

40-69

Total

4

2

6

0

0

0

0.2

0.2

0.4

0.0 (0.0-19.2)

0.0 (0.0-19.2)

0.0 (0.0-9.6)

14

12

26

1

1

2

0.8

1.2

2.0

1.3 (0.2-7.1)

0.8 (0.2-4.7)

1.0 (0.3-3.7)

18

14

32

1

1

2

1.0

1.4

2.4

1.0 (0.2-5.7)

0.7 (0.1-4.1)

0.8 (0.2-3.0)

Exp =expected number, Obs =observed number, CI=confidence interval, X=data not shown in order to maintain confidentiality of participants
Page 50 Health Hazard Evaluation Report No. 2003-0112

APPENDIX D

Recommendations Made by NIOSH in October 2003 for a Spirometry Testing Program at the ConAgra 

Snack Foods Plant in Marion, Ohio

Purpose: To detect abnormal lung function in workers that may be related to inhalation of flavoring chemicals.

General Considerations

Spirometry is the most sensitive and reliable test to detect airways obstruction. Performance of spirometry must 

carefully follow the guidelines of the American Thoracic Society (enclosed) to ensure high quality tests. Worker 

spirometry test results should be reviewed by a physician who is aware of the potential for workplace exposure to 

flavoring chemicals to adversely affect lung function, has reviewed this Appendix, and the American Thoracic 

Society guidelines.

Who should be tested and how often?

• Mixers every three to four months

• Non-mixers who enter the slurry room need testing every six months

• QA workers (i.e., those who microwave many bags of product per work shift) every three to four months

• Workers newly assigned to work in the QA lab, the slurry room, or in a job requiring entry into slurry 

room need a baseline test prior to starting work in these areas.

Criteria

• Airways obstruction: FEV1/FVC ratio below the lower limit of normal as indicated by the Hankinson 

1999 spirometry reference values (reference enclosed).

• Excessive decline in FEV1: A decrease greater than 15 % from the baseline value. 

Abnormal Spirometry or Excessive Decline in FEV1: How to Proceed?

• Abnormal spirometry in new worker: 

o Refer the worker to their personal physician for evaluation (unless he/she has already had an 

evaluation and/or diagnosis). 

o Avoid placement of the worker in the QA lab or a mixing job, or job requiring entry into slurry 

room. 

• New airways obstruction, or decline in FEV1 greater than 15 % from the baseline, in a current worker

o Refer the worker to an occupational medicine physician or pulmonary specialist for further 

evaluation which may include the following medical tests:

ß Full pulmonary function testing with spirometry followed by bronchodilator, diffusing 

capacity (DLCO), and lung volumes

ß Chest x-ray

ß High resolution chest CT scan with inspiratory and expiratory views

o Provide the physician with information on flavoring-related lung disease (e.g., August 2002 New 

England Journal of Medicine article (enclosed), or NIOSH Alert (when published)).

o Prevent any further exposure of the worker to flavoring chemicals if the physician diagnoses 

flavoring-related lung disease or other lung disease that may be exacerbated by exposure to 

flavoring chemicals.

Additional Considerations

• Any suspicion of flavoring-related lung disease in a current worker should prompt an evaluation of the 

workplace to identify any contributing factors. These may include:

o Ventilation or other equipment malfunction

o Lack of worker compliance with, or understanding of, company policies regarding respiratory 

protection or work practices to prevent exposure to flavoring-related chemicals.
Health Hazard Evaluation Report No. 2003-0112 Page 51

o Inadequate exposure controls

• The 15% fall in FEV1 criterion for referral of workers for additional medical evaluation should be 

reassessed in two years. The results of these evaluations may indicate the need for a lower threshold for 

referring workers.
Page 52 Health Hazard Evaluation Report No. 2003-0112

EVALUATION CRITERIA

To assess the hazards posed by workplace exposures, NIOSH investigators use a variety of environmental 

evaluation criteria. These criteria suggest exposure levels to which most workers may be exposed for a working 

lifetime without experiencing adverse health effects. However, because of wide variation in individual 

susceptibility, some workers may experience occupational illness even if exposures are maintained below these 

limits. The evaluation criteria do not take into account individual hypersensitivity, pre-existing medical 

conditions, possible interactions with other work place agents, medications being taken by the worker, or 

environmental conditions. 

The primary sources of evaluation criteria for the workplace are: NIOSH Criteria Documents and Recommended 

Exposure Limits (RELs)1, the Occupational Safety and Health Administration (OSHA) Permissible Exposure 

Limits (PELs)2, and the American Conference of Governmental Industrial Hygienists (ACGIH®) Threshold Limit 

Values (TLVs®).3 The objective of these criteria for chemical agents is to establish levels of inhalation exposure 

to which the vast majority of workers may be exposed without experiencing adverse health effects.

Occupational health criteria are established based on the available scientific information provided by industrial 

experience, animal or human experimental data, or epidemiologic studies. Differences between the NIOSH 

RELs, OSHA PELs, and ACGIH® TLVs® may exist because of different philosophies and interpretations of 

technical information. It should be noted that RELs and TLVs are guidelines, whereas PELs are standards which 

are legally enforceable. OSHA PELs are required to take into account the technical and economical feasibility of 

controlling exposures in various industries where the agents are present. The NIOSH RELs are primarily based 

upon the prevention of occupational disease without assessing the economic feasibility of the affected industries 

and as such tend to be conservative. A Court of Appeals decision vacated the OSHA 1989 Air Contaminants 

Standard in AFL-CIO v OSHA, 965F.2d 962 (11th cir., 1992); and OSHA is now enforcing the previous 1971 

standards (listed as Transitional Limits in 29 CFR 1910.1000, Table Z-1-A). However, some states which have 

OSHA-approved State Plans continue to enforce the more protective 1989 limits. NIOSH encourages employers 

to use the 1989 limits or the RELs, whichever are lower.

Evaluation criteria for chemical substances are usually based on the average personal breathing zone exposure to 

the airborne substance over an entire 8- to 10-hour workday, expressed as a time-weighted average (TWA). 

Personal exposures are usually expressed in parts per million (ppm), milligrams per cubic meter (mg/m3), or 

micrograms per cubic meter (μg/m3). To supplement the 8-hour TWA where there are recognized adverse effects 

from short-term exposures, some substances have a short-term exposure limit (STEL) for 15-minute peak periods; 

or a ceiling limit, which is not to be exceeded at any time. Additionally, some chemicals have a "skin" notation to 

indicate that the substance may be absorbed through direct contact of the material with the skin and mucous 

membranes. 

It is important to note that not all workers will be protected from adverse health effects if their exposures are 

maintained below these occupational health exposure criteria. A small percentage may experience adverse health 

effects because of individual susceptibility, a pre-existing medical condition, previous exposures, and/or 

hypersensitivity (allergy). In addition, some hazardous substances may act in combination with other work place 

exposures, or with medications or personal habits of the worker (such as smoking, etc.) to produce health effects 

even if the occupational exposures are controlled to the limit set by the evaluation criterion. These combined 

effects are often not considered by the chemical specific evaluation criteria. Furthermore, many substances are 

appreciably absorbed by direct contact with the skin and thus potentially increase the overall exposure and 

biologic response beyond that expected from inhalation alone. Finally, evaluation criteria may change over time 

as new information on the toxic effects of an agent become available. Because of these reasons, it is prudent for 

an employer to maintain worker exposures well below established occupational health criteria.
Health Hazard Evaluation Report No. 2003-0112 Page 53

Diacetyl, Acetoin, and 2-Nonanone

The ketones, diacetyl, acetoin, and 2-nonanone are predominant components of artificial butter flavorings and are 

extremely irritating to skin, eyes, mucous membranes and the respiratory tract. Currently, there are no NIOSH, 

OSHA, or ACGIH® occupational exposure standards or guidelines for them.

Acetaldehyde

Acetaldehyde is a colorless liquid used as a flavoring agent and adjuvant. When ingested or inhaled it can irritate 

the eye, nose, and throat. The Food and Drug Administration regulates it as a direct food additive and a synthetic 

flavoring substance. The OSHA PEL is 200 ppm (8-hour TWA). Acetaldehyde is considered a potential 

occupational carcinogen by the U.S. Environmental Protection Agency (EPA), the International Agency for 

Research on Cancer (IARC), and NIOSH. For this reason NIOSH recommends that occupational exposure levels 

of acetaldehyde be kept at the lowest feasible concentration (LFC). ACGIH® has a ceiling limit of 25 ppm.

Acetic acid and Butyric acid

Acetic acid is a colorless liquid with a strong vinegar-like odor. It is used in making dyes, drugs, plastics, food 

additives, and insecticides. The OSHA PEL is 10 ppm (8-hour TWA). NIOSH has an REL of 10 ppm (10-hour 

TWA) and a ceiling limit of 15 ppm. ACGIH® also has a TLV® of 10 ppm (8-hour TWA) and a ceiling limit of 

15 ppm. 

Butyric acid is a colorless liquid with the smell of rancid butter. It is a low molecular weight fatty acid and can be 

found as a fermentation product in butter and beer. It is used in the manufacture of plastics. Currently, there are 

no NIOSH, OSHA, or ACGIH® occupational exposure standards or guidelines.

Volatile Organic Compounds

Volatile organic compounds (VOCs) describe a large class of chemicals which are organic (i.e., containing 

carbon) and have a sufficiently high vapor pressure to allow some of the compound to exist in the gaseous state at 

room temperature. These compounds are emitted in varying concentrations from numerous indoor sources and 

chemicals including, but not limited to, carpeting, fabrics, adhesives, solvents, paints, cleaners, waxes, cigarettes, 

combustion sources, and the flavorings used in the production of microwave popcorn.

Studies have measured wide ranges of VOC concentrations in indoor air as well as differences in the mixtures of 

chemicals which are present. Research also suggests that the irritant potency of these VOC mixtures can vary. 

The use of total VOC concentration as an indicator, however, has never been standardized and neither NIOSH nor 

OSHA currently has specific exposure criteria for VOC mixtures.

Particulates, Not Otherwise Classified

Often the chemical composition of the airborne particulate does not have an established occupational health 

exposure criterion. It has been the convention to apply a generic exposure criterion in such cases. Formerly 

inappropriately referred to as “nuisance” dust, the preferred terminology for the non-specified particulate is now 

"particulates, not otherwise classified” (PNOC) (ACGIH® TLV®), or "particulates, not otherwise regulated"

(PNOR) (OSHA PEL).

 

The OSHA PELs for PNOR are 15.0 mg/m3 (total dust) and 5.0 mg/m3 (respirable fraction), determined as 8-hour 

averages. The ACGIH® recommended TLV® for exposure to PNOC is 10.0 mg/m3 (total dust, 8-hour TWA) and 

3 mg/m3 (respirable dust). [See page 5 of this report]. These are generic criteria for airborne dusts which do not 
Page 54 Health Hazard Evaluation Report No. 2003-0112

produce significant organic disease or toxic effect when exposures are kept under reasonable control. These 

criteria are not appropriate for dusts that have a biologic effect and may not be appropriate for evaluating general 

particulate matter in microwave popcorn packaging facilities.

References

1. NIOSH [2003]. Pocket guide to chemical hazards. Cincinnati, OH: U.S. Department of Health and Human 

Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, DHHS (NIOSH) publication No.97-140.

2. CFR [1997]. 29 CFR 1910.1000 Code of Federal Regulations. Washington, DC: U.S. Government Printing 

Office, Office of the Federal Register.

3. ACGIH [2003]. 2003 TLVs® and BEIs®; threshold limit values for chemical substances and physical agents. 

Cincinnati, OH: American Conference of Governmental Industrial Hygienists.
DEPARTMENT OF HEALTH AND HUMAN SERVICES

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