NIOSH HEALTH HAZARD EVALUATION REPORT 

HETA #2006-0153-3022 

Sara Lee Foods 

Storm Lake, Iowa 

October 2006 

DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health
ii 

PREFACE

The Hazard Evaluation and Technical Assistance Branch (HETAB) 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 (OSHA) Act of 1970, 29 U.S.C. 669(a)(6) which authorizes 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. 

HETAB 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 Bradley King and Elena Page of HETAB, Division of Surveillance, Hazard 

Evaluations and Field Studies (DSHEFS), and Amir Khan of the Engineering and Physical Hazards 

Branch (EPHB), Division of Applied Research and Technology (DART). Field assistance was provided 

by Srinivas Durgam and Diego Belanger. Analytical support was provided by Jennifer Ernst of the 

Chemical Exposure Monitoring Branch (CEMB) of DART. Desktop publishing was performed by Robin 

Smith. Editorial assistance was provided by Ellen Galloway. 

Copies of this report have been sent to employee and management representatives at Sara Lee Foods and 

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. Copies may be 

purchased from the National Technical Information Service (NTIS) at 5825 Port Royal Road, Springfield, 

Virginia 22161. 

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 Health Hazard Evaluation 

Highlights of the NIOSH Health Hazard Evaluation 

The National Institute for Occupational Safety and Health (NIOSH) received a management 

request for a health hazard evaluation (HHE) at Sara Lee Foods in Storm Lake, Iowa. The 

management requested a follow-up evaluation to assess soluble chlorine and trichloramine 

exposures to evisceration line area workers in their poultry processing facility. In an HHE 

conducted in 2002-2003, NIOSH investigators made recommendations, which the company has 

implemented, to reduce worker exposures to these compounds. NIOSH investigators conducted 

the follow-up investigation in June 2006. 

What NIOSH Did

 We tested the air for chlorine-related 

compounds called chloramines. 

 We asked workers about eye and 

respiratory symptoms they had at work. 

 We identified new engineering and 

ventilation controls installed since the 

previous evaluation. 

What NIOSH Found

 We found a considerable reduction in the 

number of evisceration line area workers 

reporting eye and respiratory symptoms. 

 We found reduced levels of soluble 

chlorine compounds in the evisceration 

line area compared to the previous 

investigation. 

What Sara Lee Foods Managers Can Do 

 Continue to monitor reported health 

problems. 

 Perform routine maintenance on the 

ventilation and engineering controls. 

What Sara Lee Foods Employees Can Do 

 Tell health personnel at work if you have 

health problems that may be associated 

with the work environment.

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 #2006-0153-3022
iv 

Health Hazard Evaluation Report 2006-0153-3022 

Sara Lee Foods 

Storm Lake, Iowa 

October 2006 

Bradley King, MPH, CIH 

Elena Page, MD, MPH 

Amir Khan, MS 

SUMMARY

On February 23, 2006, the National Institute for Occupational Safety and Health (NIOSH) received a 

request for a health hazard evaluation (HHE) from management of Sara Lee Foods in Storm Lake, Iowa. 

The company requested a follow-up to a previous evaluation of chloramine exposure to evisceration line 

area workers in the poultry processing facility. In 2002-2003, NIOSH investigators conducted an HHE 

(HETA 2002-0257-2916) at the worksite in response to a request for technical assistance from the 

Occupational Safety and Health Bureau of the Iowa Division of Labor regarding complaints of eye and 

respiratory irritation. A survey of evisceration line and dark meat area workers regarding these symptoms 

was conducted in 2002. An exposure evaluation for chloramine compounds was conducted in 2003. The 

company has since implemented the majority of the engineering controls NIOSH investigators 

recommended and asked NIOSH to return to evaluate these controls. 

On June 5-8, 2006, NIOSH investigators conducted a site visit to the Sara Lee Foods facility. Personal 

breathing zone (PBZ) and area air samples were collected for soluble chlorine (a combination of chlorine 

byproducts such as monochloramine, dichloramine, hypochlorous acid, and hypochlorite) and 

trichloramines in the evisceration line and dark meat areas of the facility. Questionnaires were 

administered to workers from the evisceration line to determine the extent of work-related symptoms 

experienced in the previous 4 weeks. Engineering and ventilation controls implemented since the previous 

evaluation were identified and documented. Results of this symptom and exposure evaluation were 

compared to results from the previous investigation. 

Rates of all symptoms reported by evisceration line area workers were much lower during this visit than 

during the site visit made in June 2002. Exposure levels for soluble chlorine were reduced in the 

evisceration line area. 

The potential health hazard documented in HETA 2002-0257-2916 has been effectively 

addressed by Sara Lee Foods facility management. The reduced rates of symptoms 

reported by evisceration line area workers paired with reduced levels of soluble chlorine 

compounds in this area demonstrate the effectiveness of the new engineering controls 

implemented at this facility. 

Keywords: NAICS 311615 (poultry processing), turkeys, chlorine, chloramine, soluble chlorine, 

trichloramine, eye irritation, upper respiratory irritation, evisceration, engineering controls.
Table of Contents 

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

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

Highlights of Health Hazard Evaluation .................................................................................................iii

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

Introduction and Background ...................................................................................................................1

Methods........................................................................................................................................................1

Industrial Hygiene ..................................................................................................................................1

Medical.....................................................................................................................................................2

Evaluation Criteria .....................................................................................................................................2

Chloramines.............................................................................................................................................3

Soluble Chlorine..................................................................................................................................3

Trichloramine......................................................................................................................................3

Results ..........................................................................................................................................................3

Engineering Controls..............................................................................................................................3

Industrial Hygiene ..................................................................................................................................5

Medical.....................................................................................................................................................6

Discussion and Conclusions .......................................................................................................................6

Recommendations.......................................................................................................................................7

References....................................................................................................................................................7
Health Hazard Evaluation Report No. 2006-0153-3022 Page 1 

INTRODUCTION AND 

BACKGROUND

In May 2002, the National Institute for 

Occupational Safety and Health (NIOSH) 

received a health hazard evaluation (HHE) 

request from the Occupational Safety and Health 

Bureau of the Iowa Division of Labor after they 

received a complaint from an employee of BilMar Foods, Inc., a turkey processing facility 

employing approximately 600 workers in Storm 

Lake, Iowa. (Since the time of the original 

request, the Bil-Mar Foods facility has been 

renamed a Sara Lee Foods facility.) The request 

for technical assistance noted that employees in 

the evisceration line area were experiencing 

symptoms such as eye and respiratory irritation, 

and that the Occupational Safety and Health 

Bureau had not been able to determine the cause. 

It was suspected that chloramines, specifically 

trichloramine (NCl3) was a primary cause of the 

reported symptoms because of the interaction 

between the super-chlorinated water and the 

nitrogenous material from the turkeys.1 

The request resulted in several site visits 

conducted by NIOSH investigators to determine 

the prevalence of work-related symptoms and to 

evaluate chlorine and chloramine exposures. A 

survey of evisceration line and dark meat area 

workers regarding these symptoms was 

conducted in 2002. An exposure evaluation for 

chloramine compounds was conducted in 2003. 

The NIOSH investigators found that 

concentrations of chloramine compounds 

(trichloramine and soluble chlorine) were 

significantly higher in the evisceration line area 

than in the dark meat area, which had little to no 

use of super-chlorinated water. The levels of 

soluble chlorine compounds measured by 

personal breathing zone (PBZ) air samples were 

significantly higher for employees who reported 

work-related stuffy or itchy nose, frequent 

sneezing, cough, and burning or stinging eyes. 

In addition, the levels of trichloramine were 

significantly higher in employees who reported 

burning or stinging eyes. NIOSH issued a final 

HHE report on the investigation in October 

2003. Recommendations included improving 

general and local exhaust ventilation and 

ensuring consistent chlorine levels in the chiller 

tanks. 2 In November 2003, NIOSH engineers 

visited the facility and made a series of more 

detailed recommendations for reducing worker 

exposures to chloramines. Recommendations 

provided to the company included further 

assessing and modifying the facility’s ventilation 

system in order to maximize its ability to dilute 

and exhaust airborne contaminants.3

In February 2006, NIOSH received a request for 

a follow-up evaluation from the management of 

the Sara Lee Foods facility to evaluate and 

comment on their progress in reducing 

symptoms and exposures as the result of the new 

engineering and ventilation controls. In June 

2006, a site visit was conducted to determine the 

efficacy of these controls by evaluating the 

levels of chloramine compounds in the 

evisceration and dark meat areas of the facility 

and by determining the prevalence of symptoms 

experienced by employees on the current 

workforce in the evisceration line area. 

METHODS

Industrial Hygiene 

PBZ and area air samples were collected for 

soluble chlorine and trichloramines in the 

evisceration line and dark meat areas of the 

facility using samplers that were a combination 

of an absorption tube (analyzed for soluble 

chlorine, the combination of chlorine 

compounds such as monochloramine, 

dichloramine, hypochlorite, and hypochlorous 

acid) and a treated filter cassette (analyzed for 

trichloramine) according to a draft method under 

development at NIOSH. Samplers were 

constructed from a tube containing silica gel 

coated with sulphamic acid and a 37-millimeter 

(mm) polystyrene cassette containing two quartz 

fiber filter pads in series soaked in sodium 

carbonate and diarsenic trioxide. Analysis 

involved a simple extraction followed by 

inductively coupled plasma atomic emission 

spectroscopy (ICP-AES) for both tube and filter. 
Page 2 Health Hazard Evaluation Report No. 2006-0153-3022 

During sampling, air was pulled through the 

silica gel-containing tube prior to passing 

through the filter-containing cassette. The 

soluble chlorine compounds were collected in 

the silica gel-containing tube, while the 

trichloramine passed through the tube. The 

trichloramine was then trapped separately by the 

filters as it chemically reacted with them. The air 

samples were collected using calibrated SKC 

Hi-Flow sampling pumps at a flow rate of one 

liter per minute (Lpm). The sampling pumps 

were pre- and post-calibrated using a primary 

standard to verify the flow rate. Samplers were 

shipped overnight to the NIOSH laboratory after 

daily sampling. Upon receipt, the samples were 

immediately desorbed and stored in the dark in a 

refrigerator until analysis. 

The samples were desorbed by placing the 

impregnated silica gel from the tube into a 20 

milliliter (mL) vial. Ten mL of a 1 gram/liter 

(g/L) sulfamic acid solution was added to each 

vial and rotated for 30 minutes. The sample 

extracts were decanted into another vial and 

refrigerated until analysis. Samples were 

analyzed for chloride using an ICP-AES method 

at a wavelength of 134.724 nanometers (nm). An 

instrumental limit of detection (LOD) was 

determined to be 7 micrograms (μg)/sample, 

with an instrumental limit of quantitation (LOQ) 

of 25 μg/sample. 

During analysis of the filters, each filter was 

removed from the cassette and placed in a 20 

mL sample vial. After 10 mL of deionized water 

was added, the samples were rotated for 30 

minutes. Sample filters were refrigerated and 

then filtered prior to analysis on the ICP-AES at 

a wavelength of 134.724 nm. An instrumental 

LOD for trichloramine was determined to be 6 

μg/sample with an LOQ of 19 μg/sample. 

For calculation of geometric means, values for 

sampling results that were ‘non-detectable’ were 

assigned the value of one half the LOD. 

Medical 

A confidential questionnaire was administered 

by NIOSH personnel in either Spanish or 

English to all evisceration line area workers 

present on the day shift. It consisted of questions 

about demographics (age, gender); occupational 

descriptors (job title, years worked, work 

department); personal history of allergies, 

eczema, asthma, and smoking; upper and lower 

respiratory symptoms at work in the last 4 weeks 

(not related to cold or seasonal allergies); and 

whether those symptoms remained the same, got 

worse, or got better on days off work. This 

questionnaire was identical to that used during 

the site visit in June 2002. 

EVALUATION CRITERIA

As a guide to the evaluation of the hazards posed 

by workplace exposures, NIOSH field staff 

employ environmental evaluation criteria for the 

assessment of a number of chemical and 

physical agents. These criteria are intended to 

suggest levels of exposure to which most 

workers may be exposed up to 10 hours per day, 

40 hours per week for a working lifetime 

without experiencing adverse health effects. It 

is, however, important to note that not all 

workers will be protected from adverse health 

effects even though their exposures are 

maintained below these levels. A small 

percentage may experience adverse health 

effects because of individual susceptibility, a 

pre-existing medical condition, and/or a 

hypersensitivity (allergy). In addition, some 

hazardous substances may act in combination 

with other workplace exposures, the general 

environment, or with medications or personal 

habits of the worker to produce health effects 

even if the occupational exposures are controlled 

at the level set by the criterion. These combined 

effects are often not considered in the evaluation 

criteria. Also, some substances are absorbed by 

direct contact with the skin and mucous 

membranes, and thus potentially increases the 

overall exposure. Finally, evaluation criteria 

may change over the years as new information 

on the toxic effects of an agent become 

available. 

The primary sources of environmental 

evaluation criteria for the workplace are: (1) 

NIOSH Recommended Exposure Limits 

(RELs),4

 (2) the American Conference of 
Health Hazard Evaluation Report No. 2006-0153-3022 Page 3 

Governmental Industrial Hygienists’ (ACGIH®) 

Threshold Limit Values (TLVs®),5

 and (3) the 

U.S. Department of Labor, Occupational Safety 

and Health Administration (OSHA) Permissible 

Exposure Limits (PELs).6

 Employers are 

encouraged to follow the OSHA limits, the 

NIOSH RELs, the ACGIH TLVs, or whichever 

are the more protective criteria. 

OSHA requires an employer to furnish 

employees a place of employment that is free 

from recognized hazards that are causing or are 

likely to cause death or serious physical harm 

[Occupational Safety and Health Act of 1970, 

Public Law 91–596, sec. 5(a)(1)]. Thus, 

employers should understand that not all 

hazardous chemicals have specific OSHA 

exposure limits such as PELs and short-term 

exposure limits (STELs). An employer is still 

required by OSHA to protect their employees 

from hazards, even in the absence of a specific 

OSHA PEL. 

A time-weighted average (TWA) exposure 

refers to the average airborne concentration of a 

substance during a normal 8- to 10-hour 

workday. Some substances have recommended 

STEL or ceiling values which are intended to 

supplement the TWA where there are 

recognized toxic effects from higher exposures 

over the short-term. 

Chloramines 

Chloramines are formed by the reaction between 

chlorine disinfectants and nitrogenous 

compounds such as ammonia, amines, or 

organic nitrogen-containing material. The 

species and concentrations of chloramine are 

influenced by the concentration of residual 

chlorine, ammonia (or other nitrogen sources), 

pH, and temperature.7

 In general, the lower the 

pH and the greater the chlorine to ammonia 

ratio, the higher the likelihood of producing 

chloramines. 

Soluble Chlorine 

The term soluble chlorine has been used in this 

report to designate a combination of chlorine 

compounds collected using the silica gelcontaining tube portion of the sampler used. 

These chlorine compounds include 

monochloramine, dichloramine, hypochlorous 

acid, and hypochlorite. No occupational 

exposure criteria have been developed for 

soluble chlorine or for its specific possible 

constituents. 

Trichloramine 

Trichloramine, or nitrogen trichloride (NCl3), is 

a brownish-yellow gas, has a pungent chlorine 

odor (sometimes described as rotting grapefruit 

or geraniums), is a strong irritant, and causes 

excessive tearing of the eyes.8

 NCl3 has low 

solubility, aerates easily, and decomposes 

rapidly in sunlight. Eye and respiratory tract 

irritation appear to be the primary effects of 

exposure, although asthma has been documented 

in lifeguards and swimming instructors.9

 The 

irritant characteristics of NCl3 seem to be similar 

to that of chlorine.10 Occupational exposure 

criteria for NCl3 have not been established. 

RESULTS

Engineering Controls 

The request from the facility’s management 

asked NIOSH investigators to evaluate and 

comment on their progress in reducing 

symptoms and exposures after implementation 

of engineering and ventilation controls 

previously recommended by NIOSH 

investigators. The progress made in 

implementing these recommendations is briefly 

discussed below. 

Chlorination of water: NIOSH investigators 

recommended that the concentration of chlorine 

in the chlorinated water be constantly 

maintained at the USDA-recommended level. 

Implementation Status: Sara Lee Foods has 

installed a system that allows more consistent 

chlorination levels in the chillers. 

General Ventilation: The fog machine tests 

conducted by NIOSH investigators during the 

previous site visit demonstrated that ventilation 

in the evisceration line area was non-uniform. 

Exhaust fans in the evisceration line area 
Page 4 Health Hazard Evaluation Report No. 2006-0153-3022 

appeared to be drawing contaminated air past the 

workers’ breathing zones. According to the 

design specifications provided by the plant, the 

total ventilation of the evisceration line area was 

low and needed to be upgraded. According to 

Hixson, an engineering and architecture 

consultant hired by Sara Lee Foods to help them 

troubleshoot the ventilation deficiencies in the 

operation of the evisceration line area, this area 

had an estimated 7.6 air changes per hour 

(ACH). 

The overall airflow pattern of the evisceration 

line area also needed to be improved to ensure 

adequate and uniform laminar air flow. The 

distribution of air in any ventilated room 

depends on the size, type, and locations of 

ventilation supply and exhaust diffusers. During 

the previous visit, it was observed that the 

supply and exhaust locations in the evisceration 

line area were detrimental to uniform 

ventilation, promoting short-circuiting and 

creation of dead spaces. In order to ensure 

uniform ventilation in the evisceration line area, 

NIOSH investigators recommended the supply 

and exhaust ductwork of the evisceration line 

area be appropriately re-designed and relocated. 

Implementation Status: In the evisceration line 

area, a new make-up air unit was added that 

supplies 30,000 cubic feet per minute (cfm) of 

filtered and conditioned outside air to the area 

via two diffusers (15,000 cfm per diffuser). Two 

new exhaust fans with 15,000 cfm capacity each 

were added on the opposite side of the new 

supply airflow diffusers in the evisceration line 

area and are located over areas where high levels 

of chloramine aerosolization occurred. One of 

the new exhaust fans is installed over the second 

high-pressure inside/outside bird washer, while 

the other is installed between chillers A and B. 

One of the existing 7,200 cfm exhaust fans is 

relocated over the first bird washer to improve 

the overall air circulation patterns in the 

evisceration line area. It is estimated that the 

new ventilation increased the air changes from 

7.6 to 19 ACH in the evisceration line area. 

Bird Washers: There are two bird washers in the 

evisceration line area, a bird-scrubber at the start 

of the processing line, and a high-pressure 

inside/outside bird washer at the end of the line 

(just prior to separation of the white and dark 

meat). Substantial quantities of superchlorinated water were used in these washers to 

disinfect the birds. The scrubbing of the birds in 

these washers generates aerosols. As each bird 

that had been saturated with super-chlorinated 

water exited the washer, these compounds were 

aerosolized into the work environment through 

drag-out of aerosol-laden air. NIOSH 

investigators recommended that the ventilation 

system for the evisceration line area be modified 

to include local exhaust ventilation (LEV) for 

both washers. 

Implementation Status: The facility eliminated 

the spraying of super-chlorinated water for 

washing the inside/outside of the birds in the 

second washer. Currently, regular city water is 

used for washing birds in this washer. A new 

15,000 cfm exhaust fan is installed over the 

inside/outside bird washer, and an existing 

exhaust fan of 7,200 cfm has been relocated over 

the first bird washer. 

 

Chiller: The chiller used to hold turkey necks 

was not covered or exhausted with LEV. This 

open chiller contained super-chlorinated water 

and was located near the center of the 

evisceration line area. NIOSH investigators 

recommended the chiller be exhausted to 

prevent the escape of airborne contaminants into 

the work environment resulting from the 

interactions of chlorinated water in the tank and 

the organic matter from the turkey necks. 

Implementation Status: The facility has 

eliminated the use of super-chlorinated water in 

this chiller and has substituted it with regular 

city water. 

High-pressure Cleaning: High-pressure bird 

washing occured in all of the reprocessing and 

salvage stations. Splashing and spraying of the 

birds with both city and super-chlorinated water 

provided ample opportunity for aerosolization of 

chloramines and soluble chlorine compounds. 

Chlorinated water was sprayed with enough 

force so that the enclosures used for 
Health Hazard Evaluation Report No. 2006-0153-3022 Page 5 

reprocessing and salvage were ineffective with 

some of the spray hitting the operator. The 

high-pressure cleaning that occured on breaks 

and during the cleaning shift can also potentially 

aerosolize chloramines and soluble chlorine 

products from the floor. NIOSH investigators 

recommended that low pressure cleaning 

methods be explored that involve lower water 

pressure and nozzle velocity. Exploration of 

different nozzle designs was recommended to 

minimize aerosolization and splashing onto the 

operator and the floor. NIOSH investigators also 

recommended modifying the existing centralized 

high pressure chlorinated water system to reduce 

pressure and thus minimize aerosolization of 

chlorine compounds. 

Implementation Status: The facility installed 

and uses low-pressure water nozzles in the 

reprocessing and salvage work stations to 

minimize aerosolization and splashing. 

Trough: An open trough ran through the 

evisceration line area and caught used superchlorinated water and discarded or dropped 

turkey parts under the evisceration line. The 

purpose was to direct the used water away from 

the evisceration line area to be treated and 

disposed of properly. During the previous visit, 

turkey parts in the trough frequently built up and 

required periodic cleaning to ensure the trough 

was fully operational in directing the used water 

away from the evisceration line area. The 

frequent clogging resulted in a poor flow of 

water through the trough and a buildup of 

standing water and turkey parts inside the 

trough, with the potential for overflow of 

contaminated water into the surrounding area. 

To minimize frequent clogging of the trough, 

NIOSH investigators recommended covering the 

trough with screens. NIOSH investigators also 

recommended constructing new troughs in areas 

where the current trough did not run to capture 

the contaminated water. 

Implementation Status: The facility has 

rerouted the used water from the inside/outside 

bird washer directly into the trough. This change 

provides for a very strong flow of water through 

the trough, ensuring continuously flowing water, 

which prevents buildup of stagnant water and 

turkey parts inside the trough. 

Work Stations: The reprocessing and salvage 

work stations were grouped into pairs and were 

exhausted by a single exhaust fan. A qualitative 

evaluation of these work stations by NIOSH 

investigators indicated that very little ventilation 

was present. Smoke tests indicated the work 

station exhaust fans had inadequate capture 

velocity. The poor work station ventilation 

performance was attributed to the undersized 

exhaust ducts and improper connection to the 

work station. Because the primary goal of these 

work stations is to capture contaminants released 

during reprocessing and salvage tasks, NIOSH 

investigators recommended that the exhaust 

system for these work stations be redesigned to 

provide optimum capture velocities. 

Implementation Status: Sara Lee Foods 

addressed this issue by increasing the exhaust 

airflow at these work stations through 

modifications of existing ventilation systems. 

Industrial Hygiene 

Results from the PBZ and area air sampling in 

the evisceration line and dark meat areas are 

summarized in Tables 1-4. Table 5 compares the 

geometric means of the PBZ and area air sample 

results for soluble chlorine from the 2003 

exposure assessment site visit (“pre-controls”) to 

the geometric means of the sample results from 

the 2006 site visit (“post-controls”). 

Additionally, it lists the percentages of samples 

that returned a result of “non-detectable” for the 

PBZ and area air samples in both areas. Fewer 

than a third of the samples returned “nondetectable” results. In order to calculate 

geometric means, values for sampling results 

that were “non-detectable” were assigned the 

value of one half the LOD. 

As shown in Table 5, the geometric mean for the 

PBZ sample results for soluble chlorine in the 

evisceration line area (the site of the complaints 

of respiratory and eye irritation in the original 

request in 2002) was reduced from 63.5 μg per 

cubic meter (μg/m3

) to 24.3 μg/m3. The 

geometric mean for the area air sample results in 
Page 6 Health Hazard Evaluation Report No. 2006-0153-3022 

this area was reduced from 129.5 μg/m3 to 19.0 

μg/m3

. Both of these reductions were 

statistically significant, with a P value of less 

than 0.05. In 2003, the mean of PBZ soluble 

chlorine levels measured in the evisceration line 

area was significantly higher than the mean of 

PBZ levels in the dark meat area. However, in 

2006, the results showed no statistically 

significant difference in the means of PBZ levels 

for soluble chlorine between the two areas. As 

shown in Table 5, higher percentages of samples 

that returned “non-detectable” levels were seen 

in the 2006 results compared to the 2003 results. 

This is a result of a higher LOD for the 2006 

samples versus the 2003 samples. 

Specific geometric means for the PBZ and area 

air samples for trichloramines in the dark meat 

and the evisceration line areas were not 

calculated due to the very high percentage of 

“non-detectable” sample results returned. All 

samples in the dark meat area returned “nondetectable” levels of trichloramines for the 2006 

site visit, and 67% of samples in the evisceration 

line area returned “non-detectable” levels. As an 

estimate, the geometric mean for the 

trichloramines would be less than or equal to 

12.5 μg/m3

, the minimum detectable 

concentration based on a sample volume of 480 

liters. 

Medical 

All 55 evisceration line area employees on the 

first shift who were present on the day of the 

interviews participated. Eleven evisceration line 

area employees were either ill or on vacation 

that day. Eighteen of the 55 participants had 

participated in June 2002. The rest had been 

hired since that time. Table 6 compares basic 

demographics of the participants in June 2002 to 

those at this site visit. They were similar in mean 

age, tenure, gender distribution, and smoking 

history. Table 7 compares the prevalence of 

work-related symptoms between the two time 

periods. Rates of all symptoms were lower at 

this visit than in June 2002. Two of the 

participants of the 2006 survey who reported eye 

symptoms stated they were specifically from a 

fan blowing in their faces. Most employees who 

reported symptoms at this visit reported that they 

were less severe than before the controls were 

implemented. 

DISCUSSION AND 

CONCLUSIONS

The controls implemented in the Sara Lee Foods 

facility included ventilation improvements and 

other engineering controls designed to reduce 

employee exposures to chlorine byproducts. 

These controls were focused in the evisceration 

line area, where significantly more employees 

had reported symptoms such as work-related 

wheezing, coughing, sneezing, and watery eyes 

during the 2002 site visit compared to 

employees in the dark meat area. The beneficial 

effect of the engineering controls implemented 

since that site visit is evidenced by the 

considerable reduction in symptoms reported by 

evisceration line area workers during the 2006 

site visit, as well as a considerable decrease in 

soluble chlorine compound concentrations in the 

evisceration line area. Management also 

reported a considerable drop in the number of 

health complaints reported to them in the time 

period after implementation of the controls 

compared to the time period before control 

implementation. 

On the days sampling was performed during the 

2003 exposure assessment, the mean TWA 

soluble chlorine concentrations were 

significantly higher for persons who reported 

burning or stinging eyes, itchy or stuffy nose, 

cough, asthma symptoms, and frequent 

sneezing, compared to those who did not report 

such symptoms. Mean TWA soluble chlorine 

concentrations were also higher for persons who 

reported watery eyes and sore throat, but not 

significantly so. After the controls were 

implemented, soluble chlorine concentrations in 

the evisceration line area were reduced as were 

symptoms reported by workers in this area. The 

levels of soluble chlorine in the dark meat area 

were higher this time, but comparable to the 

evisceration line area, where symptoms were 

now infrequently reported. 
Health Hazard Evaluation Report No. 2006-0153-3022 Page 7 

Because 100% of dark meat PBZ and area air 

samples for trichloramine returned levels of 

“non-detectable” and 67% of the evisceration 

line area air samples for trichloramine returned 

levels of “non-detectable,” accurate geometric 

means could not be calculated to compare 

against 2003 results. When much more than half 

of the data are “non-detectable” results, 

assigning the value of one half the LOD to all 

“non-detectable” results to calculate a geometric 

mean results in imprecise estimates of the 

geometric mean and is not recommended.11 A 

ten-fold increase in the LOD in 2006 compared 

to 2003 may be a factor in the number of ‘nondetectable’ results returned. LODs for analyses 

are sample set specific, and are therefore subject 

to change between sample sets. 

As in 2003, the findings of the current 

evaluation need to be considered in light of 

several methodologic limitations. One limitation 

is the intermittent and unpredictable nature of 

the exposure and symptoms, possibly related to 

fluctuations in the amount of nitrogenous 

material from the turkeys and in chlorine 

concentration in the water (although minimized 

by new controls). Therefore, results may vary 

depending on the conditions at the specific time 

of the sampling and may not represent exposures 

on a consistent, everyday basis. An additional 

limitation is the change in the LOD and LOQ 

(and resulting minimum detectable 

concentrations [MDC] and minimum 

quantifiable concentrations [MQC]) for the 2006 

study compared to the 2003 study. Although the 

same analytic method was utilized for both 

studies, variation in LODs can occur for a 

variety of reasons. These include instrument or 

operator variability as well as the difficulty in 

creating standards against which to compare the 

samples. Continuing work on this analytical 

method is planned by NIOSH. As was the case 

in the 2003 study, data points fall between the 

MQC and the MDC, which limits the ability to 

state with confidence that the results reported 

represent the exact level of exposure. 

The trend in reduced levels of symptoms 

reported by evisceration workers paired with 

reduced levels of soluble chlorine compounds in 

this area demonstrate the effectiveness of the 

engineering controls Sara Lee Foods 

management has implemented in this facility. 

RECOMMENDATIONS

1. Sara Lee Foods should perform routine 

maintenance on the ventilation and engineering 

controls. 

2. Sara Lee Foods management should 

continue to monitor reported health problems. 

3. Employees should tell health personnel at 

work if they have health problems that may be 

associated with the work environment. 

REFERENCES

 1. Sanderson W, Weber A, Echt A [1995]. 

Case reports: epidemic eye and upper respiratory 

irritation in poultry processing plants. Appl 

Occup Environ Hyg 10(1):43-49. 

 2. NIOSH [2003]. Hazard evaluation and 

technical assistance report: Bil-Mar Foods, Inc., 

Storm Lake, 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, NIOSH HETA 

Report No. 2002-0257-2916. 

 3. NIOSH [2003]. Walk-through report: 

observations and recommendations for reducing 

exposure to chloramines at Bil-Mar Foods, Sara 

Lee Inc., Storm Lake, 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, NIOSH Report 

No. EPHB 295-11a. 

 4. NIOSH [1992]. Recommendations for 

occupational safety and health: compendium of 

policy documents and statements. Cincinnati, 

OH: U.S. Department of Health and Human 

Services, Public Health Service, Centers for 

Disease Control and Prevention, National 
Page 8 Health Hazard Evaluation Report No. 2006-0153-3022 

Institute for Occupational Safety and Health, 

DHHS (NIOSH) Publication No. 92-100. 

 5. ACGIH® [2006]. 2006 TLVs® and 

BEIs®: threshold limit values for chemical 

substances and physical agents. Cincinnati, OH: 

American Conference of Governmental 

Industrial Hygienists. 

 6. CFR [2003]. 29 CFR 1910.1000. Code of 

Federal Regulations. Washington, DC: U.S. 

Government Printing Office, Office of the 

Federal Register. 

 7. Segna L [1998]. Nitrogen trichloride 

Summary Reston, VA: Applied Environmental 

Health and Safety Inc. USDA Contract No. 53-

3A84-7-09 Draft Report. 

 8. Barbee SJ, Thackara JW, Rinehart WE 

[1983]. Acute inhalation toxicology of nitrogen 

trichloride. Am Ind Hyg Assoc J 44(2):145-146. 

 9. Thickett KM, McCoach JS, Gerber JM, 

Sadhra S, Burge PS [2002]. Occupational 

asthma caused by chloramines in indoor 

swimming-pool air. Eur Respir J 19:827-832. 

 10. Gagnaire F, Axim S, Bonnet P, Hecht G, 

Hery M [1994]. Comparison of the sensory 

irritation response in mice to chlorine and 

nitrogen trichloride. J Appl Toxicol 14:405-409. 

11. Hornung RW, Reed LD [1990]. Estimation 

of average concentration in the presence of 

nondetectable values. Appl Occup Environ Hyg 

5(1):46-51. 
Health Hazard Evaluation Report No. 2006-0153 Page 9 

Table 1. Personal Breathing Zone Air Sampling Results 

HETA 2006-0153 Sara Lee Foods 

Evisceration Line Department, June 6-8, 2006 

Date Location Soluble Chlorine (tube)†

μg/m3

Trichloramines (filter) 

μg/m3

6-Jun Cropper/Lung Gun 41.2 ND

7-Jun Cropper/Lung Gun 15.6* ND* 

8-Jun Cropper/Lung Gun ND ND 

6-Jun Floater 43.3 ND 

6-Jun Hind Halfer 56.3 ND 

7-Jun Hind Halfer 77.5* ND* 

7-Jun Hind Halfer 55.8* 19.4* 

8-Jun Hind Halfer 38.2 (7) 

6-Jun Ice Attendant 41.4 10 

6-Jun Inspector's Helper 68.4 ND 

7-Jun Pinning Room 25.3* ND* 

6-Jun Salvage 44.6 (7) 

7-Jun Salvage (11.8*) 22.6* 

7-Jun Salvage 76.3* ND* 

8-Jun Salvage ND (6) 

6-Jun Trimming ND ND 

7-Jun Trimming ND* ND* 

8-Jun Trimming ND ND 

7-Jun Two-point 19.9* ND* 

8-Jun Two-point ND ND 

6-Jun Vent Gun 55.4 ND 

GEOMETRIC MEAN: 24.3 --**

 MDC: 14.6 12.5 

 MQC: 52.1 39.6 

ND denotes ‘non-detectable level’ 

μg/m3

 denotes micrograms per cubic meter 

MDC denotes minimum detectable concentration based on a sample volume of 480 L 

MQC denotes minimum quantifiable concentration based on a sample volume of 480 L 

†

 field blank corrected 

* may represent an underestimation of typical concentration due to a stoppage in the production line for approximately 2 hours 

due to a power loss 

** a geometric mean cannot be calculated due to the high percentage of samples with ‘non-detectable’ levels 

() trace amount 
Page 10 Health Hazard Evaluation Report No. 2006-0153-3022 

Table 2. Area Air Sampling Results 

HETA 2006-0153 Sara Lee Foods 

Evisceration Line Department, June 6-8, 2006 

Date Location Soluble Chlorine (tube)†

μg/m3

Trichloramines (filter) 

μg/m3

6-Jun Chiller 324.7 72.1 

7-Jun Chiller 275.7* ND* 

6-Jun Delunger 44.6 ND 

7-Jun Final Wash Q.A. Station 34.1* 206.3* 

7-Jun I/O Bird Wash 38.2* ND* 

6-Jun Ice Machine (11.3) ND 

8-Jun Inspector's Helper ND 21.4 

8-Jun Pinning Room ND ND 

8-Jun Salvage (4.2) 85.5 

7-Jun Trimming (2.0*) 210.5* 

8-Jun Trimming ND ND 

6-Jun Vent Gun (11.1) ND 

GEOMETRIC MEAN: 19.0 --** 

 MDC: 14.6 12.5 

 MQC: 52.1 39.6 

ND denotes ‘non-detectable level’ 

μg/m3

 denotes micrograms per cubic meter 

MDC denotes minimum detectable concentration 

MQC denotes minimum quantifiable concentration 

†

 field blank corrected 

* may represent an underestimation due to a stoppage in the production line for approximately 2 hours due to a power loss 

** a geometric mean cannot be calculated due to the high percentage of samples with ‘non-detectable’ levels 

() trace amount 
Health Hazard Evaluation Report No. 2006-0153 Page 11 

Table 3. Personal Breathing Zone Air Sampling Results 

HETA 2006-0153 Sara Lee Foods, Dark Meat Department, June 6-8, 2006 

Date Location Soluble Chlorine (tube)†

μg/m3

Trichloramines (filter) 

μg/m3

8-Jun Floater ND ND 

6-Jun Hot Dog Grind 79.3 ND 

7-Jun Hot Dog Grind 93.1* ND* 

6-Jun Thigh Trim Table 95.8 ND 

7-Jun Thigh Trim Table 92.6* ND* 

8-Jun Thigh Trim Table 18.9 ND 

8-Jun Thigh Trim Table ND ND 

GEOMETRIC MEAN: 35.1 --** 

 MDC: 14.6 12.5 

 MQC: 52.1 39.6 

Table 4. Area Air Sampling Results 

HETA 2006-0153 Sara Lee Foods, Dark Meat Department, June 6-8, 2006 

Date Location Soluble Chlorine (tube)†

μg/m3

Trichloramines (filter) 

μg/m3

7-Jun Hot Dog Grind 44.1* ND* 

8-Jun Hot Dog Grind ND ND 

6-Jun Reprocessing Station 60 ND 

7-Jun Reprocessing Station 82.7* ND* 

6-Jun Side Trimmer 15.7 ND 

8-Jun Thigh Deboner ND ND 

GEOMETRIC MEAN: 23.8 --** 

 MDC: 14.6 12.5 

 MQC: 52.1 39.6 

ND denotes ‘non-detectable level’ 

μg/m3 denotes micrograms per cubic meter 

MDC denotes minimum detectable concentration 

MQC denotes minimum quantifiable concentration 

†

 field blank corrected 

* may represent an underestimation of typical concentrationdue to a stoppage in the production line for approximately 2 hours 

due to a power loss 

** a geometric mean cannot be calculated due to the high percentage of samples with ‘non-detectable’ levels 
Page 12 Health Hazard Evaluation Report No. 2006-0153-3022 

Table 5. Comparison of Geometric Mean Soluble Chlorine Concentrations 

HETA 2006-0153 Sara Lee Foods 

Pre-Controls (June 2-6, 2003) and Post-Controls (June 6-8, 2006) 

Location

Pre-Control 

Soluble 

Chlorine (tube) 

μg/m3

Post-Control 

Soluble 

Chlorine (tube) 

μg/m3

Evisceration (PBZ) 63.5 (0% ND) 24.3 (29% ND) 

Evisceration (Area) 129.5 (0% ND) 19.0 (25% ND) 

Dark Meat (PBZ) 9.4 (0% ND) 35.1 (29% ND) 

Dark Meat (Area) 7.4 (0% ND) 23.8 (33% ND) 

MDC: 1.5 14.6 

MQC: 183.3 52.1 

μg/m3 denotes micrograms per cubic meter 

MDC: minimum detectable concentration based on a 480 L sample volume 

MQC: minimum quantifiable concentration based on a 480 L sample volume 

Table 6. Comparison of Employee Demographics and Selected Characteristics 

HETA 2006-0153 Sara Lee Foods 

June 2002 to June 2006 

June 2002 June 2006

Participation Rate 68/69 (98%) 55/66 (83%) 

Mean Age (Years) 36 37 

Mean Tenure at Sara Lee Foods

(Years) 

8 8 

Gender

 Male 

 Female 

57% 

43% 

55% 

45% 

Smoking Status

 Current 

 Former 

24% 

32% 

29% 

20% 
Health Hazard Evaluation Report No. 2006-0153 Page 13 

Table 7. Comparison of Work-Relateda

 Symptoms Reported by Evisceration Line Workers 

HETA 2006-0153 Sara Lee Foods 

 June 2002 to June 2006 

June 2002 

n=68

June 2006 

n=55 

Itchy, runny nose 32 (47%) 7 (13%)

Watery eyes 31 (46%) 7 (13%)

Frequent sneezing 30 (44%) 0 (0%)

Cough 28 (41%) 4 (7%)

Burning or stinging 

eyes

27 (40%) 7 (13%)

Asthma symptomsb 18 (26%) 0 (0%)

Stuffy nose 17 (25%) 5 (9%) 

Wheezing 15 (22%) 0 (0%)

Sore throat 14 (21%) 2 (4%)

Shortness of breath 10 (15%) 1 (2%)

Chest tightness 10 (15%) 0 (0%)

a defined as experienced at work during the last 4 weeks, but improved on days away from work b

 defined as wheezing, or any two of the following three symptoms: cough, chest tightness, and shortness of breath 
DEPARTMENT OF HEALTH AND HUMAN SERVICES 

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