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Health H~zard 

Evaluation 

Report 

HETA 83-375-1521

FEDERAL GRAHi INSPECTION 

SERVICE-USDA

PORTLAND., OREGON 

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 PREFACE 


The Hazard Evaluations and Technical Assistance Branch of NIOSH conducts field 

investigations of possible health hazards in the workplace. T~ese 

investigations are conducted under .the authority of Section 20(a)(€) cf the 

Occupational Safety and Health Act of 197C, 2~ U.S.C. 66S'(a)(6) which 

authorizes the Secretary of Health .and Human Services, following a written 

request from any employer 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. 

The Hazard Evaluations and Technical Assistance Branch also provides, upon 

request, medical, nursing, and industrial hygiene technical and consultative 

assistance (TA) to Federal, state, and local agencies; labor; industry and 

other groups or individuals to control occupational health hazards and to 

prevent related traurr.a and disease. 

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Mention of company names or products does not constitute endorsement by the 

National Institute for Occupational Safety and Health. 
HETA 83-375-1521 , NIOSH INVESTIGATORS: 


OCTOBER 1984 Steven H •. Ahrenholz, C.I.H. 
 · FEDERAL GRAIN INSPECTION SERVICE-USDA 

PORTLAND, OREGON 

I. SUMMARY 

On July 27, 1983, the National Institute for Occupational Safety and 

Health (NIOSH) was requested .by the United States Department of ' 

' 

Agriculture (USDA) Federal Grain Inspection Service (FGIS) . to evaluate f 

grain fumigant exposures of grain samplers and inspectors in the 

Portland Oregon field office. A recent increase 'in movement of heavily treated g~ain and a subsequent increase in reports of health effects by workers prompted the request. . . 

FGIS workers are required to manually collect representative grain 

samples from incoming grain shipments at the export elevators and to 

test and inspect the sample. These tests include a "sniff test" which 

requires an odor determination in which air in or directly above the 

grain is inhaled by the inspector. 

NIOSH i.nvestigators conducted an initial survey November 14-18, 1983 

with a fo-llow-up April 8-14, 1984. Evaluation of worker exposures to 

fumigants anq workplace contaminants was conducted primarily by personal exposure monitoring. Short-term .sampling for grain fumigant 

concentrations in situations where higher levels were anticipated was 

alsb undertaken. Contaminants evaluated were: carbon disulfide, 

carbon monoxide, carbon ·tetrachloride, chloroform, · 1,2-dichloroethylene, ethylene dibromide, ethylene dichloride, grain dust, methyl _bromide, and no.i se. 

Results from the initial survey found full shift exposures to ethylene dibromide (maximum 21 parts per billion or.pp~), carbon disulfide 

(maximum 738 ppb), and carbon tetrachloride {maximum 1960 ppb}. 

Respective NIOSH evaluation criteria are 45 ppb, ethylene dibromide; 

1000 ppb, carbon disulfide; and 2000 ppb, carbon tetrachloride. No 

chloroform, ethylene dichloride, or 1,2-dichloroethylene were 

detected. Personal exposures (54 samples) to fumigants during the 

follow-up survey had a maximum of 0.49 ppb ethylene dibromide and 391 

ppb of carbon tetrachloride. Carbon monoxide exposures of truck 

samplers were at trace levels (NIOSH criteria 35 ppm). No personal 

exposures to carbon disulfide or methyl bromide were documented. Area • 

noise measurements were all below 90 decibels on the A weighted scale 

and did .not indicate any excessive noise levels. Area concentrations 

of respirable dust were negligible (maximum concentration· 0.37 

milligrams per cubic meter (mg/m3)) (OSHA standard - 5 mg/m3). · Short-term fumigant sampling associated with fumigated grain fn 

railcars indicated extremely high short-term fumigant concentrations. 

Carbon disulfide concentrations in short-term samples ranged up to 
' · Page 2 - Health Hazard Evaluation Report No. 83-375 

levels in excess of 327,000 ppb. Carbon tetrachloride samples went up 

to a level in excess of 1,136,000 ppb. NIOSH ceiling concentrations 

for both carbon disulfide (10,000 ppb) and carbon tetrachloride (2,000 

ppb) were exceeded - although comparison of all short-term samples obtained to these criteria may not be appropriate. 

The results of 'this investigation indicate a serious potential health 

hazard due to high fumigant concentrations present in and immediately 

adjacent to incoming treated grain. Since workers often must rely on 

sensory perception of fumigants, whose odor thresholds can be above the 

level considered to cause adverse erfects, overexposures may occur 

without their knowledge. Inspectors appear to be at risk from direct 

inhalation of low levels of fumigants, some of which are suspected 

carcinogens. Recommendations, both short-term and long term are 

offered concerning personal protective equipment~ hazard communication, 

and treatment of fumigated grain. Long-term recommendations are 

coupled with Research Needs and include the aeration of fumigated grain 

to be inspected and modification or elimination of the sniff test as a 

routine procedure. 

KEYWORDS : SIC 4782 (Inspection and Weighing Services Connected with 

Transportation), grain inspection, grain fumigants, sniff test, carbon 

disulfide - CAS # 75-15-0, carbon tetrachloride - CAS # 56-23-5, 

ethylene dibromide - CAS # 106-93-4, grain elevators - export. 
Page 3 - Health Hazard Evaluation Report No. 83-375 

II. INTRODUCTION 

On July 27, 1983 the National Institute for Occupational Safety and ·Health (NIOSH) received a request from the United States Department of 

Agriculture (USDA) Federal Grain Inspection Service (FGIS) to evaluate 

exposure to fumigants at grain sampling and inspection s"tations 

operated by the Portland, Oregon Field Office. 

Subsequent to the initial survey, conducted November 14-18, 1983, the 

request was expanded by USDA to include railcar samples and 

inspectors. An interim report issued in February 1984, presented 

exposure data obtained during the initial survey. Workers were found 

to be exposed to ethylene dibromide~ carbon disulfide, and carbon 

tetrachloride. 

A follow-up survey was conducted April 8-14, 1984. Additionally, 

short-term sampling for fumigants was undertaken. 

III . BACKGROUND 

A. · Federal Grain Inspection Service 

The U. s. Grain Standards Act requires that, with some exceptions, 

all U. s. export grain undergo inspection as it is loaded on board 

the vessel that will carry it overseas. The inspection is 

performed by FGIS or by state agencies that have been delegated 

export inspection authority. The state of Oregon operated its own 

grain inspection service until early 1978 when the service became 

federally operated. The Federal Grain Inspection Service currently 

performs all grain inspections required under state law for grain 

moving into the state for export. Additionally, Oregon state law 

requires grain shipments to be inspected by an official agency if 

U. s. grade standards are used for price determination. 

FGIS grain samplers and inspectors are represented by Local 3781 of 

the American Federation of Government Employees. 

B. Process Description 

The sampling and inspection process consists of two stages. Grain 

samplers ·assigned to truck inspections will collect a 2500 gram (g) 

grain sample from each truck. This is done with the 1:1se of a 6 to 

12 foot (1.8 to 3.7 meter) grain trier. The grain sampler must 

either enter the truck (in the case of semi-trailer vansf or walk 

out on the ·top of open top trailers (flat bottom and hopper bottom 
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Page 4 - Health Hazard Evalu~.tion Report No. 83-375 

trailer.s) and, following a predetermined sampling pattern, insert 

the probe into the grain, rotate the hollow trier to obtain samples 

at all levels, remove the trier and empty it on a sample canvas. 

This process is repeated until the required number of probes have 

been made. This composite sample is put into a sampling bag and 

delivered to the on-site laboratory for inspection. 

The sample, upon delivery to the laboratory, is weighed and then 

split down into various fractions for inspection. A divider is 

used to separate the sample into a 1000 g w~rk sample and a 1000 g 

file sample. A 250 g sample used for moisture determination is 

also obtained . Inspectors have _reported experiencing fumigant 

odors during sample division on the Boernere divider. The 1000 g working sample is then run through a dockage tester which removes 

the trash (chaff, weed seeds, stones, etc.) from the grain. The 

weight of grain per bushel is determined from this sample. 

The subsamples obtained from the dockage tester are · used in the 

percentage analysis where total defects, heat damage, and odor are 

determined. Odor is determined by conducting a "sniff test" which 

requires the inspector to place his/her nose i1T111ediately above the 

grain sample and check for a sour or musty grain odor. This 

procedure results in direct inhalation exposure of the inspector to 

residual fumigants present in the grain. The remaining 250 g sample is placed on a grain ·sizer which separates out broken and 

shrunken kernels. Grain perceived as fumigated is permitted to sit 

for four hours prior to inspection and the sniff test, but after it 

has passed through the splitter and dockage tester, to allow for 

offgassing of fumigants. The sample is placed off to the side or 

on an unused work bench area during this time. No local exhaust • 'i 

ventilation is present. · 

In the case of railroad hopper car sampling the sampler must obtain 

a sample by probing the grain through the hatch covers (or lids) on 

top of the car. Depending upon the level of grain in the 

compartments of the car, the sampler may or may not have to get 

down into the car itself. 

In 'the· past cars that had not been (placarded, indicating that no 

fumigants were applied to the grain during or after the present load was placed in the car for shipment), had been opened by the 

samplers while cars that were placarded were opened by elevator 

personnel and allowed to aerate passively for 24 hours outdoors 

with the top of the car open. Currently. elevator personnel open 

all railcars. The grain is probed in a manner similar to that for 

truck shipments. The samples are handled in an identical manner to 

tr~ck samples once in the lab. 

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Page 5 - Health Hazard Evaluation Report No. 83-375 

An additional method of sampling grain, used primarily for railcars . during inclement weather and for grain coming from barges or going · onto ships, is the use of diverter samples. This is a mechanical 

sampling device that periodically passes through the grain flow on 

its way into the elevator and directs it through a series of tubes 

to a collection point in the FGIS lab. 

The number of grain shipments officially inspected in the Portland 

FGIS District can exceed 100,000 per year. 

Grain traffic was not considered by workers or supervisory staff to 

be moving at maximal levels during either of NIOSH's surveys in 

Portland. The variability in grain movement activity from 

day-to-day can be appreciated by the fact that during our follow-up 

survey among three major export elevators, incoming truck ·shipments 

ranged from Oto about 60 and railcar shipments from 16 to about 80 

cars. During the NIOSH surveys there were reports of occasional 

fumigant odors associated ~ith grain being processed, however all 

workers displayed ·a degree of wariness when handling any grain 

perceived or reported as having a fumigant odor. The general 

consenus among workers was that the number of grossly fumigated 

shipments coming into the elevators was down during our surveys. 

C. Problem Description 

Management at both the Field Inspection Office and national level 

have expressed concern over the increase in incidence in workers 

experiencing ill effects associated with fumigated grain. Reported 

symptoms include loss of coordination, mental c.onfusion, dizziness, 

lightheadedriess, headache, fatigue and drowsiness, burning or 

watery eyes, · and nausea. Individuals reporting these symptoms are 

the samplers - especially when opening unplacarded fumigated railcars or upon entering trucks having fumigated grain, and the 

on-site lab personnel involved with preparing and grading samples. Perception of the grain as having been treated is primarily sensory 

in the .absence of placarding. Additionally, the inspectors are 

concerned about potential chronic health effects associated with 

long term inhalation of fumigant mixtures. 

Numerous difficulties and unknowns are encountered in both 

evaluating the problem and in taking corrective action. The 

identification of treated. unpl.acarded grain shipments before an 

overexposure has occurred in almost impossible under current 

operating procedures. The loss of placards on treated shipments 

and failure to remove old placards from untreated shipments increases the uncertainty of using placarding alone to designate 

fumigated grain. Difficulties in identifying the source 

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Page 6 - Health Hazard Evaluation Report No. 83-375 

of fumigated grain due to such things as sales-in-transit and 

multiple loading and/or railcar pick up points make deter~inations 

of where the grain was treaded tedious and unreliable. 

Non-uniformity in fumigant application procedures an<f rate (amount 

used) as well as lack of information on the identity of the 

fumigant used hinders the evaluation and appropriate handling of 

treated grain. Multiple fumigation of grain during storage and 

shipment may re·sult in the presence of higher residual fumigant levels in recently loaded grain shipments even though the grain was 

riot directly treated prior to the last shipment. Ambient and .grain 

temperatures may influence the release of volatile fumigants from 

the grain. · Methods for aerati ng and/or ·handling fumigated grain in 

some manner making it "safe" for conducting a sniff test remain 

speculative and unproven as to their efficacy. The question of 

what constitutes sufficient aeration of grain in order to conduct a 

sniff test is still unanswered~· Predicting when the movement of 

fumigated grain is most likely to increase remains subjective. 

Methods of testing grain to determine if it· is free of fumigants or 

at least will not present a health hazard ·to workers handling the 

grain is fraught with controversy, inappro·priate applications of 

exposure criteria, and questionable or unproven measurement 

practices. 'The interaction of different grains with fumigants as 

far as fumigant retention and release is another issue. Do 

different grains interact similarly or differently when fumigated with the same and different fumigants? Essentially grain shipments 

arrive at the elevators "as is" with no historical information 

about the grain or shipment. 

In addition to the fumigant health hazard to the central nervous 

system, the effects, when experienced by samplers acci·dently exposed to fumigants, present a serious safety hazard. Sure 

footedness is essential when on top of and around railroad cars and 

semi-trailers. 

D. Current Approach to Evaluating Fumigant Levels 

The method of assessing fumigant levels of grain shipments by the 

elevators is done exclusively with direct reading indicator tubes. 

Although this is one of the most expedient methods in attempting to 

evaluate a rather elusive fumigant exposure situation, this system 

is subject to all of the previously discussed (see Background} shortcomings in addition to the inherent limitations of ·indicator 

tube systems. The significance attached to what may be a cursory 

and/or improperly obtained fumigant concentration determination 

appears at times to be inappropriate. 

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Page 7 - Health Hazard Evalua'tion Report No. 83-375 

Additionally, any evaluation of a fumigated grain incident, after 

it has been accidentally identified or through some fumigant 

concentration determination, cannot be considered to represent the 

conditions existing during the preceeding, unevaluated time 

period. A ~4jor factor contributing to this is :the 

nonreproducibi lity of incoming grain shipments. 

E. Other Agency Regulations Concerning Fumigated Grain 

The U.S. Department of Transportation specifies in the 

Transportation Safety Act of 1974 _that movement of grain by rail 

that has been treated with flammable liquids or gases in the 

fumigation process is prohibited until either 48 hours has elapsed 

after treatrrent or the carrying vessel has been ventilated "so as 

to remove danger of fire or explosion due to the presence of 

flammable vapors" . [Section 173.9 para (a)Jl A placarding 

procedure is specified for lading whi ch has been fumigated or 

treated with poisonous li quid, solid, or gas, and the placard 

states that before unloading and entering, the car must be free of 

gas [Section 173.9 para (b)]. l No guidance is given as to how a 

shipment is determined to be "free of gas" or what constitutes a 

gas free lading. Additionally, a railcar must be thoroughly 

cleaned after poisonous materials are unloaded unless it is used 

exclusively for the carriage of poisonous material's [Section 

174.615).1 Health issues, other than those associated with 

immediate death~ are not addressed by the regu1ations. The date 

and time given on a placard, after which the shipment can be 

opened, has nothing to do with the safety of the lading as it 

pertains to fumigant exposure of workers. 

The U. S. Environmental Protection Agency currently exempts carbon 

disulfide, carbon tetrachloride, ethylene dichloride, chloropicrin, 

chloroform, methylene chloride, an6 methyl bromide from the 

requirement of a residue tolerance.2 This means that there is no 

fumigant level, which if exceeded in a grain sample, that would 

prohibit the use of the grain. The agency issued three (C) (2) (B) 

letters under the Federal Insecticide, Fungicide and Rodenticide 

Act requesting resi due, product chemistry, and toxicology data for 

carbon tetrachloride, ethylene dichloride, carbon disulfide, methyl bromide, and methylene chloride in March 1984, to registrants of 

pesticide products containing these active ingredients. This 

re-evaluation of existing exemptions from tolerances has t-een 

undertaken in response to recent findings of ethylene dipromide 

residues in foods. 

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Page 8 - Health Hazard Evaluation Report No. 83-375 

E. Surveys Conducted by NIOSH Investigators 

A NIOSH investigator conducted an initial survey at three of the 

Portland FGIS inspection sites during the week of November 14, 

1983. He conducted monitoring of truck samplers and truck 

inspectors to fumigants during their work shift. Fumigants sampled 

were ethylene dibromide. carbon disulfide. carbon tetrachloride. f 

trichloromethane or chloroform. 1.2-dichloroethane, and 

1.2~dichloroethylene. The three-truck sampling stations were 

located at Bunge Grain Corporation. Cargill Terminal. and Columbia 

Grain Terminal. · The sampling was conducted November 15-18, 1983• . 

April 8-14, 1984 NIOSH investigators conducted a follow-up survey which included personal expqsure monitoring for ethylene dibromide, 

carbon disulfide. carbon tetrachloride. methylbromide, and carbon 

monoxide. Area .samples for measurement of airborne concentrations 

of respirable dust in the lab and at truck sampling locations were 

also obtained. Short-term sampling in an effort to define higher level exposures associated with incoming .fumigated grain was also 

undertaken. The follow-up survey involved monitoring of both 

railroad car (track) samplers and truck samplers as well as the 

inspectors grading grain from these ~o incoming modes of 

transportation. FGIS inspection locations at the three elevators 

involved in the November 1983, survey were again the sites of the 

follow-up survey. Investigators also took general noise level 

measurements in work areas and by equipment used by FGIS employees. 

IV. METHODS AND MATERIALS 

A. Initial Survey 

During the initial survey exposure monitoring was conducted with 

portable. battery-operated sampling pumps each equipped with a 

manifold permitting the collection of four simultaneous samples per worker. Standard 150 milligram charcoal tubes were used for the 

collection media and the approximate flow rate through each sorbent 

tube was 100 cubic centimeters per minute for near. ful 1-shift 

sampling. Three ·of the four tubes were analyzed from each sample 

set. The fourth tube was retained until after laboratory analyses 

were completed, allowing an extra sample from each set in the event 

that additional compounds of interest requiring further analyses . were identified. · 

B. Follow-up Survey 

Sampling_during the follow-up survey included both personal 

exposure monitoring and short-term source and exposure sampling. The following types of samples were collected: 
Page 9 - Health Haza.rd Evaluation Report No. 83-375 

Personal Exposures 

- Carbon disulfide at 100 cc/min on charcoal - Carbon tetrachloride at 100 cc/min on charcoal - Ethylene dibromide at 200 cc/min on charcoal - Methyl bromide at 50 cc/min on 2 Qazi and Ketchum tubes in series ~ Carbon monoxide using Draeger long-term detector tubes 

(at 20cc/mi n) 

Area and Short-Term Samples 

- Carbon tetrachloride and carbon disulfide on standard charcoal 


tubes -- 2 in series at 1 liter per minute (Lpm); 


Area respirable dust samples using a 10 mm nylon cyclone at 1.7 

Lpm; 

- Area noise levels using a grazing incidence Type II sound level 


meter; and 


Bag ·sampling for carbon tetrachloride and carbon 

a 

disulfide using 5 L aluminized mylar bags, filling them at rate of about 1 

Lpm, ~nd analyzing the .sample on site with the use of a portable 

gas chromatograph 

Personal exposure monitoring was to determine worker exposure to .' .. 

the different contaminants encountered over several work days. ' 

Most workers for which exposure monitoring was done wore a three 

tube sampling manifold for fumigants (the first three compounds listed under Personal Exposures). Grain inspectors were asked to 

move the sorbent tube holders towards their nose during the time 

they conducted the sniff ~~t. Additionally, railcar samplers were 

monitored for methyl bromide. Truck samplers were monitored for 

carbon monoxide from truck exhaust. All sorbent tube samples were 

stored and shipped cold using blue ice. 

Short-term fumigant samples (on charcoal tubes} and bag samples 

were obtained by sampling in the grain mass in railcars, above the 

grain mass in railcars, the head space in railcars prior to fully opening the lids, in and above the laboratory grain sample, and at 

se·veral other locations such as at the grain stream whi-le dumpfog 

hopper cars, during the probing of grain in a ra·ilcar, and during 

the conduct of a sniff test. The short-term sorbent tubes required . different analytical procedures for carbon. disulfide and carbon 

tetrachloride and therefore the samples were split by the 

laboratory upon receipt. Confirmation of the presence of carbon 

disulfide and carbon tetrachloride on the short-term sorbent tubes 

by gas chromatography-mass spectroscopy was also requested. 

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Page 10 - Health Hazard Evaluation Report No. 83-375 

Carbon disulfide was analyzed by gas chromatography using NIOSH 

Method S-2483 with modifications. Benzene was used for 

desorption and the gas chromatograph was equipped with a flame 

photometric detector, operated in the sulfur mode. The limit of 

detection for carbon disulfide was 3 micrograms per sample for the 

initial survey sample set, 10 micrograms per sample on the 

follow~up survey sample set. f 

Carbon tetrachloride, chloroform, 1,2-dichloroethane, and 

1,2-dichloroethylene were analyzed by gas chromatography according 

to NIOSH Method P&CAM 1274. The desorption solvent was carbon 

disulfide .and the gas chromato[raph was equipped with a flame 

ionization detector. The following limits of detection were 

attained for the initial survey set (given in micrograms per 

sample): carbon tetrachloride, 10; chloroform, 10; 

1,2-dichloroethane, 10; and 1,2-dichloroethylene 10. The follow-up 

survey sample set was analyzed for carbon tetrachloride according 

to NIOSH Method S-3143 with modifications. The analytical limit 

of detection for this sample set was 10 ug per sample. 

Ethylene dibromide samples were analyzed by gas chromatography/electron capture detection (GC/ECD). The analyte 

was desorbed using a solution of lS methanol in benzene. The 

analytical limit of quantitation was 50 nanograms per sample with a 

limit of detection of 10 nanograms per sample in the initial survey 

set. Samples collected during the follow-up survey had a limit of 

quantitation of 23 nanograms per sample and a limit of detection of 

5 nanograms per sample. 

Methyl bromide samples were analyzed by GC/ECD. The analyte was 

desorbed using a 2 ml so.lution of 1S methanol in benzene for at 

least 1 hour. The analytical limit of quantitation was 0.44 

ug/sample and the limit of detection was 0.40 ug/sample. 

Carbon monoxide exposures were evaluated using Draeger long-term carbon monoxide tubes (Cat #CH28121) and a low flow sampling pump calibrated at a flow rate of 20 cc per minute. Tubes were read at 

the termination of the .sample. 

Respirable dust sampling used a preweighed polyvinyl chloride 

filter in a 10 millimeter (mm") nylon cyclone, respirable dust 

sampling train. The flow rate of 1.7 Lpm was established using a 

Kur~ Mass Flow Meter and a representative sampling train. 

Sampling trains were pre- and post-shift calibrated. Total weights 

were determined by weighing the samples plus the filters on an 

electrobalance and subtracting the previously determined tare 

weight of the filters. The tare and gross weighings were done ·in 

duplicate. The instrumental precision of weighings done at one 

sitting was 0.01 milligrams. Due to variable factors such as 
Page 11 - Hea·lth Hazard Evaluation Report No. 83-375 

overloading, hygroscopicity of sample, humidity, and the physical integrity of the filter itself, the actual precision can be 

considerably poorer and occasional slight net negative particulate weights can be expected. 

Short-term bag samples were collected using al'uminized mylar bags and an SKC Universal Pump®. Samples were taken to the field lab f 

where they were analyzed for carbon tetrachloride and carbon 

disulfide. Samples were analyzed using a Photovac Model lOAlO gas 

chromatograph equipped with .a photoionization detector. 

Short-term sorbent tubes for carbon disulfide and carbon 


tetrachloride were analyzed as two sample sets submitted 


sequentially. An· initial subset of the tubes collected was 

analyzed by gas chromatography using Method S-2483 with 

modifications to determine the· value of submitting the remaining 

samples for analysis. The limits of detection were 0.01 mg/sample 

for both carbon disulfide and carbon tetrachloride. 

The identities of carbon disulfide and carbon tetrachloride were 

confirmed on several of the s·hort-term sorbent tube samples. These 

samples were reanalyzed on a HP 5992 gas chromatograph/mass 

spectrometer. . ­ Noise measurements were obtained using a General Radio Type II 

sound level meter, Model 15658. The unit was calibrated before and 

after each day's ·use. Sound pressure level readings were obtained 

on both the A-weighted scale and also on the C-weighted scale. 

Slow meter response was used. - . 

Modifications used with th~ different analyses, as well as a 

further description of the bag sampling and portable chromatographic sample analyses, are present~d in Appendix A. Table 

I presents information on the effect sample· duration and volume 

have on the environmental limits of detection for the pr.imary fumigants o~ interest. · 

V. EVALUATION CRITERIA AND TOXICITY SUMMARIES 

A. Environmental Criteria: 

As a guide to the evaluation of the hazards posed by workplace 

expo.sures, NIOSH field staff ·employ environmental evaluation 

criteria for ~sse~sment 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 

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Page 12 - Health Hazard Evaluation Report No. 83-375 

workers will be protected from adverse health effects if 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 evaluation 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 increase 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 Criteria Documents and recommendation~, 

2) The American Conference of Governmental Industrial Hygienists' {ACGIH) Threshold Limit Values (TLV's), and 3) The U. s. 

Department of Labor {OSHA) occupational health standards. Often, 

the NIOSH recommendations and ACGIH TLV' 0 s are lower than the 

corresponding OSHA standards. Both NIOSH reconrnendations and ACGIH 

TLV ' s usually are based on more recent information than are the 

OSHA standards. The OSHA standards also may be required to take , , into account the feasibility of controlling exposures in various 

industries where the agents are used; the NIOSH recommended 

standards, by contrast, are based primarily on concerns relating to 

the prevention of occupational disease. In reviewing the exposure 

levels and the reconrnendations for reducing those levels found in 

this report, it should be ·noted that industry is required by the 

Occupational Safety and Health Act of 1970 to meet those levels 

specified by OSHA standards. 

A time-wei'ghted average (TWA) exposure refers-to the average airborne _concentration of a substance during a normal 8 to 10 hour 

workday.· Some substances have recommended short-term exposure 

limits or ceiling values which are intended to supplement the TWA 

where there are recognized toxic effects from high short-term 

ex·posures. 

Evaluation Criteria used in this report are presented-in. Table II 

and the following Toxicity Discussion. 
Page 13 - Health Hazard Evaluation Report No. 83-375 

B. Toxicity Discussion: 

1. Carbon Disulfide 

Carbon disulfide vapor causes nar~osis at high concentrations; 

repeated exposure to low concentrations causes damage to the ... central and peripheral nervous systems and may accelerate the 

development of or worsen coronary heart .disease. Reproductive disorders occur, such as azospermia, menstrual irregularities, 

and spontaneous abortion. Other reported effects of exposure 

to carbon disulfide are ocular changes (retinal degen.eration, 

corneal opacities, disturba~ces of color vision, corneal 

anesthesia, diminshed pupillary reflexes, microscopic aneurysms (in the retina), gastrointestinal disturbances (chronic 

gastritis and achlorhydria), renal impairment (albuminuria, 

microhematuria, elevated blood urea nitrogen, diastolic 

hypertension), and liver damage. Effects commonly caused by repeated exposure to carbon disulfide vapor are exemplified by 

a group of workers with a time-weighted average (TWA) exposure of 11.5 ppm (range 0.9 to 127 ppm) who complained of headaches 

and dizziness. In other workers with a TWA of 186 ppm (range 23 to 378 ppm), complaints also included sleep disturbances, 

fatigue, nervousness, anorexia, and weight loss. The 

end-of-day exposure coefficient of the iodine azide test on 

urine was a good indicator of workers who were or had been 

symptomatic.6 

Dermatitis and vesiculation may result from skin contact with 

the vapor or liquid.14 Exposure by inhalation of vapor may 

be compounded by percutaneous absorption of liquid or 

vapor . IS Cutaneous exposure of rabbits to carbon disulfide 

vapor resulted in measureable carbon disulfide concentration fn 

the exhaled air. Carbon disulfide vapor absorbed through the 

skin was present in solution in the blood and in combined 

form. The authors of this study concluded that under 

conditions of grain fumigation, carbon disulfide vapor concentrations may reach a level where skin absorption, .as 

another route of exposure, is a possibilfty~16 A study done 

by Cesaro17 in which the intact skin of male . human subjects 

was exposed to CS2 vapors resulted in no detectable CS2 in 

exhaled air subsequent to exposure. In this particular study 

the lowest concentration which could be measured was iO ppm (30 mg/m3). No .measurement of exposure chamber cs2 - concentrations were obtained. The study assumed that a 20 

minute exposure period along with wrapping one arm in CS2 

soaked cotton would sufficiently expose the subjects. to a 

degree where the contaminants of interest would appear in 

exhaled air. 

., 
Page 14 - Health Hazard Evaluation Report No. 83-375 

rhe ~urrent OSHA Permissible Exposure Limit is 20 ppm for an 


eight-hour TWA and has an accep:table ceiling concentration of 


30 ppm. The acceptable maximum peak above the acceptable 
 ceiling concentration for an eight hour shift is 100 ppm for 30 


minutes and this maximum peak must be included in the 


eight-hour TWA calculation.12 . 


NIOSH recommends a permissible exposure limit of 1 ppm {3


mg/m3) over a workshift of up to 10 ho·urs (in a 40-hour work 


week) with a ceiling of 10 ppm (30 mg/m3) averaged over a 


IS-minute period. The NIOSH recommended exposure limit is 


considered to be below levels at which serious health effects 


would generally be found, specifically those involving the 


cardiovascular and central nervous systems. Acute toxicity by 


CS2 can be avoided by applying the re¢01T1T1ended ceiling
 limits. 


Carbon disulfide is not known to be an eye irritant and since 


the odor threshold (7.7 ppm or less) is below the PEL it has 


good warning properties.6 


2. Carbon Tetrachloride 

Carbon tetrachloride (CCl4) vapor is a narcotic and causes 

severe damage to the liver and kidneys. In animals the primary ... damage fro~ intoxication is to the liver, but in humans the 

ma·jority of fatalities have been the result of renal injury with secondary cardiac failure. In humans, liver damage occurs . more often after ingestion of the liquid than after inhaling the vapor. Human fatalities from acute renal damage have 

occurred after exposure for about one-half to one-hour at 

concentrations of 1000 .ppm to 2000 ppm. Exposure to high 

concentration results in symptoms of central nervous system depression including ~izziness, vertigo, incoordination, and 

mental confusion; abdominal pain, nausea, vomiting, and 

diarrhea are frequent •. Within a few days, jaundice may appear and liver injury progresses to toxic necrosis. There .are 

several reports of adverse effects in workmen ·who were 

repeatedly exposed to concentrations between 25 and 30 ppm;

nausea, vomiting, dizziness, qrowsiness, and ·headache were 

frequently noted. The effects of CC14 in humans who are 

addicted to al~ohol are more severe than usual. No adverse · symptoms resulted from repeated .exposure to 10 ppm. Hepatomas
 have been reported in several animal species exposed to carbon 


tetrachloride; human exposure has also been associated with 


hepatomas.6 Liquid cc14· can be absorbed through the 


skin.la 
Page 15 ~ Health Hazard Evaluation Report No. 83-375 

The current OSHA PEL for CCl4 is 10 ppm over an eight~hour TWA with an acceptable ceiling concentration of 25 ppm and a 

maximum acceptable peak of 200 ppm for five minutes occurring only once in any four hours and included in the overall TWA 

calculation _12 

NIOSH recommends that the TWA exposure limit to CCl4 be . maintained below 2 ppm (12.6 mg/m3) during the course of a 

workshift determined during a one-hour sampling period. 

Maintaininf exposures below this level is considered capable of 

greatly reducing the cancer risk associated with occupational 

exposure to CCl4.7 NIOSH recommends that CCl4 be 

regulated as an occupationa-1 carcinogen. 

Carbon tetrachloride has an odor threshold of about 50 ppm, which is above the PEL and is, therefore , regarded as having· poor warning properties. Carbon tetrachloride has been 

reported as being slightly irritating to the eyes, however, no 

concentration at which this occurs was given.6 

3. Ethylene Dibromide 

Ethylene dibromide (EDB) vapor is a narcotic, a severe mu~ous 

membrane irritant, and a hepatic toxin. Accidental use as a 

human anesthetic resulted in severe irritation of the 

conjunctiva and respiratory tract, followed by protracted vomiting and death. Excessive exposure may be expected to 

cause irritation of the eyes and respiratory tract. The liquid is highly irritating to human skin, causing marked erythema and 

vesiculation • . In a bioassay conducted by the National Cancer 

Institute, ethylene dibromide was found carcinogenic in rats 

and mice when fed . by gavage. The compound induced squamous cell carcinomas of the fore stomach in rats of both sexes, 

hepatocellular carcinomas in female rats, and hemangiosarcomas in male rats. ln mice of both sexes, the compound induced 

squamous cell carcinomas of the fore stomach and 

alveolar/broncheolar adenomas. In NIOSH-sponsored research, 

laboratory rats exposed to 20 ppm EDB by inhalation and also 

receiving a diet containing a.ass disulfiram experienced exceedingly high mortality levels as well as a high incidence 

of tumor~ (including hemangiosarcomas of the liver, spleen, and 

kidney). · . 

- OSHA has proposed a reduction in the EDB PEL from an eight-hour TWA of 20 ppm to 0. 10 ppm. OSHA believes that the total risk · to health of employees exposed to EDB is the result of the 

compounded risks from carcinogenicity, mutagenicity, spermatotoxicity, teratogenicity, and damage to the kidneys, 
Page 16 - Health Hazard Evaluation Report No. 83-375 

liver, spleen, respiratory tract, central nervous system, circulatory system, skin, and eyes warrants this reduction in 

PEL and substantially reduces risk. The short-term exposure limit would also be revised to 0.5 ppm over a 15-minute period from the current five minute acceptable maximum peak of 50 

ppm.11 

NIOSH has concluded in its comments on the OSHA Proposed. EDB 

Standard that an eight-hour TWA .of 0.045 ppm (45 parts per billion or ppb) will greatly reduce the ~isk of workers 

developing cancer as a result of a working lifetime exposure to 

EOB. NIOSH also concludes ihat a ceiling limit, to accommodate 

intermittent exposures in certain industries, of 0.130 ppm (130'. 

ppb) as determined in any 15 minute sampling period is 

appropriate (Internal Memorandum 11 NI0SH Comments on the 

Occupational Safety and Health Administration Proposed Standard: Occupational Exposure to Ethylene Dibro·mide 11 

November 21, 1983). 

The odor of EOB is detectable at 10 ppm, well above 

occupational exposure limits and therefore is considered to 

have poor warning properties. Ethylene dibromide is also 

reported to be an eye irritant.6 

4. Chloroform 

Acute health effects associated with short-term exposures to 

chloroform or trichloromethane are headache, drowsiness, 

vomiting, dizziness, unconsciousness, irregular heartbeat, and 

death. Liver and kidney damage may also result from exposure 

to chloroform vapor. Prolonged exposure to chloroform may 

cause liver and kidney damage. A potentiating effect of ethyl alcohol ingestion on the toxicity of chloroform vapor in the 

occupational setting is suspected, but has not been proven in 

industrial practice. Liver tumors have been reported in 

animals and the International Agency for Research on ·Cancer 

after evaluating the data on this chemical has concluded that 

chloroform is a carcinogen.6 · 

The current OSHA standard for chloroform is a ceiling level of 

50 ppm (240 mg/m3).12 NIOSH has recommended that the 

permissible exposure limit be reduced to ceiling level of 2 ppm averaged over a one hour period and that chloroform be 

regulated as· an occupational carcinogen.6 
Page 17 - Health Hazard Evaluation Report No. 83-375 

s. 112-Dichloroethane 

1.2-dichloroethane or ethylene dichloride produces similar 

acute exposure health effects for all routes of entry: ingestion. inhalation. and skin absorption. Acute exposures result in nausea. vomiting. dizziness. internal bleeding. bluish-purple discoloration of the mucous membranes and skin 

(cyanosis). rapid but weak pulse, and unconsciousness. Acute 

exposures can lead to death from respiratory and circulatory failure. Autopsies in such situations have revealed widespread 

bleeding and damage in most internal organs. Repeated long-term exposures to ethylene dichloride have resulted in 

neurologic changes, loss of appetite and other gastrojntestinal problems. irritation of mucous membranes. liver and kidney 

impairment. and death. A National Cancer Institute study indicates that ethylene dfchloride fed to laboratory rats and 

mice results in a statistically significant excess of malignant and benign tumors, as compared to controls.a Since ethylene 

dichloride causes progressive. malignant disease of various 

organs in two species of animals. NIOSH recormnends that 

ethylene dichloride be ~onsidered carcinogenic in man. NIOSH 

recommends that exposure to ethylene dichloride be kept as low 

as feasible. 

The current OSHA PEL for ethylene dichloride is 50 ppm over an 

eight-hour TWA with an acceptable ceiling concentratfon of 100 

ppm. The acceptable maximum peak above the ceiling concentration is 200 ppm for five .minutes during any three-hour 

period~12 All peak and ceiling concentrations must be 

~ncluded in the eight-hour TWA calculation. 

6. 11 2-Dichloroethylene 

·1.2-dichloroethylene vapor is a narcotic and a mucous membrane 

irritant. A concentration of 39,000 ppm was lethal to guinea pigs. and narcosis was produced. at 18,000 ppm. Dogs exposed to 

high concentrations of vapor developed superficial corneal . turbidity which was reversible. No effects were observed in 

several species with repeated exposure for up to six months at , 1000 ppm. ·rt has been used as a general anesthetic in man; one 

industrial fatality was due to very high vapor inhalation in a 

small enclosure. Exposure to 1,2-dichloroethylene may cause 

dizziness, drowsiness, and unconsciousness.6 · 

The current OSHA PEL for 1,2-dichloroethylene is 200 ppm.over a 

eight-hour TWA. 1,2-dichloroethylene is an eye irritant and 

with an odor threshold of a.as ppm is regarded as having · adequate warning properties. 

. .,-, '. i·.. \ ; 
Page 18 ~ Health Hazard Evaluation Report No. 83-375 

7. Methyl Bromide 

Methyl bromide is a severe pulmonary irritant and neurotoxin. 

It is also narcotic at high concentrations. The onset of toxic 

symptoms is usually delayed, and the latent period may be from 

30 minutes to several days. Early symptoms include headache, 

visual disturbances, nausea, vomiting, and malaise. In some 

cases eye irritation, vertigo, and tremors of the hands have 

occur.red; the tremors may progress to twitchings and finally to 

convulsions. The onset of dyspnea may herald the development of pulmonary edema. Tubular damage of the kidneys has been 

observed in fatal cases. Victims who recovered from severe 

intoxication have had .persistent central nervous system effects 

including vertigo, depression, hallucinations, anxiety and 

inability to concentrate. 6 

The current OSHA PEL for methyl bromide is 20 ppm over an 

eight-hour TWA. The ACGIH recommends an eight-hour exposure limit of 5 ppm.9 Since methyl bromide has virtually no odor 

and no immediately irritating effects, it is considered to have 

poor warning properties. 

8. Grain Dust 

Grain dust inhalation may cause three major respiratory diseases: asthma, chronic bronchitis, and grain· fever. 

Both immediate and delayed asthmatic reactions have been 

reported when asthmatic grain handlers were given bronchial 

challenges of grain dust extracts . Estimation of the 

prevalence of asthma among grain handlers is difficult due to 

self exclusion of symptomatic workers from grain dust 

exposure. Th~ long-time asthmatic grain handlers represent a 

surviving population.19 

Workers exposed to grain dust demonstrate a higher prevalence . of respiratory symptoms and rhonchi (abnormal chest sounds)

than in control populations, regardless of smoki ng history. Inhalation of grain dust causes coughing, expectoration, wheezing, chest tightness, and shortness of breath. Grain 

handlers with symptoms had impaired lung functions • . This 

impairment was either of the same magnitude as that of 

cigarette smoking or of lesser extent. The prevalence of 

chronic bronchitis with respiratory obstruction was higher in 

grain handlers regardless of smoking. Chronic bronchitis with 

evidence of airway obstruction was related to the length of 

employment. Chronic bronchitis is considered a major 

occupational health problem among grain handlers. Although 

'•.. _. 
.' 

Page 19 - Health Hazard Evaluation Report No. 83-375 

smoking is a major contributing factor to this disease, it also 

occurs in nonsmokers.19 

The incidence of grain fever has been stated to range· from 19 

to 40% in grain ·handlers. Its occurren.ce is determined largely .by excessively dusty conditions, i.e., dust concentrations 

exceeding 15 mg/m3.19 · . · · 

. . 

Grain workers exposed to. time weighted average grain dust 

concentrations of 4 mg/m3 or less generally do not express 

respiratory symptoms in excess of those reported among control 

populations.19 This is tha basis of the recommended 

time-weighted TLV of 4 mg/m3 for total dust. . .. 

. 9. Carbon Monoxide :. 

Carbon monoxide (CO) gas causes tissue hypoxia by preventing the blood from carrying sufficient oxygen. CO combines 

reversibly with the oxygen-carrying sites on the hemoglobin 

molecule with an affinity ranging from 210 to 240 times greater than that of oxygen. In addition, carboxyhemoglobin (COHB) 

in.terferes with the release of oxygen carried by unaltered 

hemoglobin. Exposure to high concentrations such as 4000 ppm and above may have only transient weakness and dizziness as the­ premonitory warnings before the individual goes into a coma. ..: ..·> : Cerebral edema is the most common early aftermath of severe 

intoxication. Exposure to concentrations of 500 to 1000 ppm • • ! 

causes the development of headache, tachypnea (rapid 

breathing), nausea, weakness, dizziness, mental confusion, and 

in ·.sorrie instances, hallucinations, and may result in brain 

damage. The affected person is commonly cyanotic (blue). 

Concentrations as low as 50 ppm result in blood COHb levels of . up to 10% in an 8-hour day. This greatly increases the risk of 

angina ·peetori s and cor·onary infarctions by decreasing the 

oxygen supply in the blood and alsQ in the myoglobin of the -heart muscle. ' Thes~ effects are aggravated by heavy work, high ambient temperatures, and high· altitudes. Pregnant women are . especially susceptible to the effects of increased CO levels. ·Smoking also increases the risk : cigarette smoke contains~% 

CO (40000 ppm), which results in 5.9% COHb if a pack a -day is .smoked. The diagnosis of co· intoxication de_pends primarily on 

the demonstration of significantly increased carboxyhemoglobin i n .the b 1ood. 6 . · - · . 

The current OSHA PEL for carbon monoxide is 50 ppm (55 mg/m3) 

averaged over an eight-hour work shift. NIOSH recommen·ds that 

the PEL be reduced to 35 ppm (40 mg/m3) with a ceiling of 200 

ppm· (230 mg/m3).6 

-: 
Page 20 - Health .Hazard Evaluation Report No. 83-375 

Carbon monoxide is an odorless, colorless, non-irritating gas and therefore . has no warning properties. 

10. Noise 

Exposure to intense noise causes hearing losses which may be 

temporary, permanent, or a combination of the two. These 

impairments are reflected by elevated thresholds of audibility 

for discrete frequency sounds, with the increase in decibels 

(dB) required to hear such sounds being used as a measure of 

the loss. Temporary hearing losses, also called auditory fatigue, represent threshold losses which are recoverable after · a period of ·time away from the noise ·. Such 1 osses may occur 

after only a few minutes of exposure to intense noise . With 

prolonged and repeated exposures (months or_years) to the same 

noise level, there may bi only partial recovery of the 

threshold losses, the residual loss ·being indicative of a 

developing permanent hearing imp~irment. · 

The losses in hearing due to exposure to intense occupational 

noise (105 dB(A) or above) tend to reach a plateau at certain 

frequencies (most notably 4000 Hertz} after about 10 years of 

exposure. The hearing loss for such frequencies , which result 

from a 10-year exposure to noise, appears to approximate the 

temporary hearing loss resulting from a single days exposure.15 · 

The OSHA PEL for continuous noise exposure is 90 dB(A) for a 

duration of eight hours per day. NIOSH and the ACGIH reconunend 

that the daily noise ex~osure or dose not eiceed 85 d~(A) over 

an eight-hour. work shift. The ACGIH also reconunends the 

inclusion of all on-the-job noise exposures of 80 dB(A) or 

greater in_calculating daily noise exposure.9 

VI . RESULTS 

A. Initial Environmental Survey 

Personal expo~ure monitoring results for fumigants conducted ­ November 14-18, 1983, are presented in Table _III. A total of 24 

personal exposure samples for ethylene dibromide, carbon d.isulfide, 

and other chlorinated fumigant ~ompounds were collected over the 

workers' full work-shift . 

(13 inspectors, . 11 . samplers): 

Ethylene dibromide full-shif~ TWA exposures ranged from 

non-detectable to 160 ug/m3 (21 ppb). Twelve samples· (so;) had 

concentrations above the analytical limit of quantit~tion, eight samples (33%) were identified as having EDB present, but below 

.r; 

{ ,1 ~- .' 

\ J 

\ 
page 21 -...Health Hazard Evaluation Report No. 83-375 

quantifiable leve.ls (trace quantities); and four samples (i6%) had 

no detectable EDB. The geometric mean (GM) concentrations for all 

samples. in which EDB was present is 2.46 ug/m3 (0.32 ppb) with a 

geometric standard deviation (GSO) of 4.81. For grain samplers, 

EDB · exposures had a GM of 1.74 ug/m3 (0. 23 ppb) with a GSD of 

2.50 and for grain 1nspectors the GM .EDB exposure value was 1.19 

ug/m3 (0. 16 ppb) with a GSD of 7.04. (All means are calculated f 

from quantifiab.le and trace. exposures, non- detectables have been 

omitted). The EDB recofflTlended ·exposure limit is 345 ug/m3 {45 ppb). . 

Carbon disulfide TWA exposures ranged from nondetectable up to 2280 


ug/m3 (738 ppb). Eleven of 24 CS2 samples (46%) were above the 


analytical limit of quantitation. The remaining 13 (54%) were 


non-detectable. The GM exposure was 208.2 ug/m3 (67 ppb) with a 


GM of 2.64 for all samples-excluding nondetectables. Grain 


samplers had exposures with a GM of 303.5 ug/m3 {98 ppb) and GSD 


of 4. 19 and g·rain inspectors had a GM exposure of 167.9 ug/m3 (54 


ppb) with a GSD of 1. 87. The recommended CS2 exposure limit is 


3000 ug/m3 (1000 ppb). 


El~ven of the 24 CCl4 samples (46%) were above the analytical 

limit of ·quantitation. The remaining 13 (54%) were 

non-detectable. Carbon tetrachloride TWA exposure ranged from 

non-detectable up to 12350 ug/m3 (1960 .ppb). The GM for all 

samples is 775 ug/m3 (123 ppb) with a GSD of 2.82. The mean 

exposure for grain samplers was 1856 ug/m3 {295 ppb), GSD of 

6.15; and for grain inspectors was 558 ug/m3 (89 ppb), GSD of 

1.46. The recommended exposure limit for CCl4 fs 12,6·00 ug/m3 


(2,000 ppb). · . 


Samples. for chloroform, ethylene dichloride, and 


1,2-dichloroethylene were all below detectable levels. 


One short-term sample taken in a railcar containing fumigated grain 


demonstrated a ·CS2 concentration of 8800 ug/m3 {28000 ·ppb) and 


a CCl4 con9entration of 32500 ug/m3 (5167 ppb). 
 . . . 

B. Follow-up Environmental Survey: 

The follow-up survey included personal exposure monitoring for 

fumigants and carbon monoxide, short-term source monitoring for 

fumigants, area respirable dust samples, and area sound level 

measurements. 
Page 22 - Health .Hazard Evaluation Report No. 83-375 

1 • . Fu~igant Exposures 

A total of 54 personal exposure samples were obtained for EDS, 

CS2, and CCl4. Twelve of the 54 EDB samples (22%) were 

above detectable limits. Six of the 54 samples (11%)' fell .. between the analytical limits of detection and quantitation. ' 

Six (11%) were quantifiable. The GM concentration for all EDB f!

samples is 0.48 ug/m3 (0.06 ppb), GSD 2.6. Ten grain . 
 samplers had EDB exposures with a mean of 0.54 ug/m3 (0.07 


p_pb), 2.4 .GSD; and two grain ·inspectors had trace exposures • . 
 Recommended exposure .limit to EDB is 345 ug/m3 (45 ppb). 


Of the 54 samples obtained for CS2, .none were determined to 

have a detectable concentration of CS2. .. i.

Ten of the 54 (18%) samples taken for determining ·CCl4 

exposures were quantifiable. The remaining 44 (81%) were below 

analytical limits of detection. The GM concentration of all 

ten samples was 480 ug/m3 (76 ppb) with a GSD of 2.3. Five 

grain samplers and five grain inspectors monitored for CCl4 

exposure ·composed this group of samples, with the GM exposure 

for grain samplers of 755 ug/m3 (120 ppb} - GSD 1.8. The 

recolTlllended exposure limit for CCl4 is 12,600 ug/m3 (2,000

ppb). 

Nine personal exposure samples· for methyl bromide were obtai ned 

for railcar samplers. None of these samples documented the 

presence of any methyl bromide during the follow-up survey. 

Results of the monitoring for grain fumigant exposure during 

the April, 1984 survey are presented in Table IV. 

2. Carbon Monoxide 

six truck samplers were monitored for carbon monoxide (CO)

exposures associated with idling truck engines in the truck -sampling area. Full shift sampling indicated that the workers 

did not encounter any significant exposures due to the idling of truck engines in these sampling areas. The two samples 

indicating trace concentrations had a small amount of color 

change in the indicating layer but produced an insufficient 

stain length to obtain any estimate of concentration. The 

minimum quantifiable CO concentration was about 10 ppm .(10000

ppb) for a 10 liter air sample. · Table V .presents carbon 

monoxide exposure monitor_ing data . · · 

.\ ·. 

 
Page 23 - Health Hazard Evaluation Report No. 83-375 

3. Short-Tenn Fumigant Sampling 

The results of short-term fumigant sampling for carbon 

disulfide and carbon tetrachlori~e are presented in Tables VI 

and VII and Figures I and II. Short-term bag sampling data 

o~tained with the use of a portable gas chromatograph .is 

presented in·Table VI along with the corresponding sorbent tube . ' 

samples. The sampling .and analytical methods used to assess 

these transient circumstances presented limitations w.hich 

restricted our ability to evaluate this type of situation. 

Analytical limits of detection, sample volume, and sample duration all influence the ~bility to evaluate fumigant 

concentration. One of the difficulties encountered with our 

portable gas chromatograph appears to· be the vast range of . 

unknown fumigant concentrations seen in grab samples. ' ': 

Concentrations ranged from· below the instruments capabilities of detection up to a level which resulted in overloading of the 

unit to the point where it was rendered nonfunctional for 

proJonged periods of time (loss of sensitivity due to "swamping the column") . Due to problems encountered with the unit no 

further presentation of the bag sampling data is given other 

than in this section. All conclusions will be drawn from 

sorbent tube sampling data. 

Short-term fumigant data were extremely eratic, with .... 

concentrations varying widely among different· samples obtained ; 

for any one car of grain, in addition to the variation in 

fumigant concentrations between different railcars. The 

highest fumigant concentrations for both CS2 and CCl4 were 

seen in the samples of railcar head spaces and samples obtained 

in the grain mass itself. Overall fumigant concentrations 

among all samples taken spanned three to four orders of 

magnitude. A total of 47 sorbent tube samples were taken along with 33 bag samples. 

Eleven of the 29 bag samples having detectable quantities of 


CS2 exceeded the respective sorbent tube sample quantities. 


The me~n concentration of CS2 among these samples was 4.7 ppm
 (GSD 11.7) compared to 3.8 ppm {GSD 16.2) for the sorbent 


tubes. Note that in Table VI the environmental limits of 


detection for different samples varies. This is influenced by
 sample volume and duration {See Table I). 


Confi~mation of the presence of CS2 and CCl4 on the 


short-term sorbent tube samples was do~e on selected samples • 
 . Both CS2 and CCJ4 were confirmed to be present on samples
 in which these compounds had already been identified with the 


gas chromotographic analyses. 


/ r-C 

'., ~r 

•. 

- - ----·..-·- - ------- ..---···- ·--·h·••• .. 
Page ·24 - Health Hazard Evaluation Report No. 83-375 

4. 	 Area Respirable Dust Sampling . 

A total of eighteen area respirable dust s·amples were obtained 

with seventeen having a measurable weight gain. The GM dust 

level wa·s 0.09 mg/m3 (GSD 2.1). Table VIII presents the 

respirable dust sampling results. · F 

5. 	 Area Sound Level Measurements 

Noise level measurements obtained on both the A- and C-weighted 

scale are presented in Table IX along with the maximum . recommended exposure time (jn hours) to a continuous noise of 

the intensity measured. · No A-weighted levels above 90dB(A) ·were measured. A total of 23 different measurements were 

obtained. " 

6. 	 Review of Fumigant Exposure Incident Reports 

A review of the OSHA Log of Federal Occupational Injuries and 

Illnesses for 1982 and 1983 indicated that there were two 

fumigant exposure incidents in 1982 for the Federal Grain 

Inspection Service, Port1and Oregon Field Office and 12 in 

1983. The occupation .of workers involved were Agricultural 

Commodity Gra~er and Agricultural Commodfty Technici~~· 

Incident reports concerning fumigant exposures were examined 

for.the time period of February through July, 1983. During this period nine fumigant exposures were reported. · Thirty 

three percent (3/9) involved grading or inspecting grain, 56% 

(5/9) involved truck sampling, and lU (1/9) involved raflcar 

grain sampling. Symptoms reported by workers were as follows : 

loss of· coordination, mental confusion, 

dizziness,lightheadness 	 89% (8/9) 

headache 33% (3/9) 

fatigue, drowisness 33% (3/9} 

burning or watery eyes 33% (3/9) 

nausea 11% (1/9) .. Eight of the reported in-stances i den ti fi ed the fumigant as an 11 80/2011 fumigant. One involved phostoxin. The age range of 

the affected workers was 27 to 34. 

­
Page 25 - Health Hazard Evaluation Report No. 83~375 

VII. DISCUSSION 

A. Personal Exposure Monitoring Results: 

Personal exposure monitoring for fumigants conducted durjng both 

the initial and follow-up surveys demonstrated the occurrence of 

measurable worker exposures to the fumigants. While no persona·1 

exposures exceeded recommended or permissible exposure limits the 

extreme variability and uncertainty associated with fumigant levels 

in grain shipments received at the elevators makes the assumption that over exposure will not occur improper. 

Almost all ethylene dibromide exposures occurred among truck grain samplers and truck grain inspectors. A decrease in ethylene . dibromide exposures between the initial and follow-up survey is 

considered attributable to the··recent banning of ethylene dibromide 

as a grain fumigant. Exposures to ethylene dibromide occurring during the follow-up survey may most likely represent exposure to 

residual levels present in older grain. The absence of any CS2 

exposures during the follow-up survey (for truck grain shipments) 

as compared to the initial survey may indicate that grain moving last November had been fumigated more recently than that brought in 

in April. that application rates were heavier, or possibly grain moved in April had been handled more after treatment allowing for 

greater aeration of the grain. Other confounding factors · previously mentioned in the Background section -may also contribute 

to this observed decrease in fumigant levels. · 

Compounds with lower vapor pressures. such as EDB and CCl4. 

appear to remain in grain for a longer period of time possibly contributing to low level ~orker exposures. This appears desirable · from the standpoint of insect eradication (as in the case of EDB) 

for grain stored in non-airtight facilities. 

Methyl bromide exposures. suspected as possibly occurring due to 

use of the compound as an EOB substitute. were not observed for 

railcar samplers. Due to the extremely high vapor pressure of 

methyl bromide. concentrations of this compound at any work 

location after the opening of a more airtight enclosure (such as a 

railcar} is considered to be very low. Therefore sampling for 

methyle bromide was limited to situations where detectaple concentrations were considered to b~ most likely to occur. 

B. Short-term Sampling Results from Fumingated Grain Shipments: 

Evaluation of fumigant concentrations in incoming railcars 

demonstrated the presence of a potentially serious health hazard. 

Railcar head space concentrations were we.11 in excess of · recommended ceiling limits for CS2 and CCl4. Consideration of 

the head space fumigant concentrations when reviewing reported 

acqte health effects and comparing them to the toxicology· of these 

compounds suggests that short-term high level acute exposures to 

CS2 and CC14 can .occur. The initial disruption of a high level head space concentration during the-opening of railcar lids by 
Page 26 - Health Hazard Evaluation Report No. 83-375 

unprotected personnel may .result in a significant exposure falling . between the reported full-shift trace exposures ·reported for 

personar exposures and the high conce~trations seen in the head 

spaces. Since fumigated and nonfumigated railcar shipments are 

indentical in a·ppearance except for placarding. worker~ opening .. unplacarded fumigated grain shipments probably will not realize the 

grain has been treated until after the exposure has. occurred. Loss f 

.of placards in transit and failure to remove placards from 

nonfumigated grain shipments were also mentioned as contributing to 

the confusion in identifying fumigated shipments. During the NIOSH 

surveys. elevator personnel were required to open up all placarded rail cars. · 

.C. Fumigant Sampling Results from In-the Mass Versus Above-the Mass: . i, 

Samples obtained in · the grain mass in. the railcars. while not 

comparable to any breathing zone or ambient air exposure limit. 

demonstrate a reservoir of fumigant vapor which can become airborne 

as the shipment is processed through the grain handling system 

enroute to its final destination. 

Comparison of in-the-mass with above-the-mass air samples shows 

that sampling done in-the-mass is not comparable to above-the-mass 

airborne fumigant concentrations. The two railcars with the 

highest head space fumigant concentrations could not be sampled in-the-mass since this grain was dumped by the ·elevator and brought 

into the house wi.thout an on site grade determination. All 

in-the-mass samples were obtained after passively aerating the 

railcars for a period of 24 hours. One must also realize that the 

question of uniformity of distribution of fumigants throughout the ·shipment has not been dete~mi ned. 

NIOSH investigators have also observed the discrepancy between 

fumigant concentrations above a grain mass versus in the grain mass 

in another instance involving fumigated grain .(Interim letter 

report. HETA 84-194. American Federation of Grain Millers. · Superior. Wisc6njin. March 1984). Concentrations of fumi~ants in · that situation ·were not observed to be as high as in this present evaluation. One reason for this may have been the .fact that in 

H.ETA 84-194 some. efforts to aerate the grain had been ongoing for a 

week .prior to sample collection. 

The debate over u.sing fumigant levels obtained in-the-grain mass 

versus above the grain mass al so r~rilai ns. Both approach.es present 

some problems. Sampling above the grain mass. especially in more · open or outdoor areas. will provide a substantial amount of .dil~tion .ventilation which. when combined with a relatively small 

sample ~olume may produce an artificially low estimation .of 

exposure risk. Not all locations or procedures thro~gh which this 

grain may ·pass ·at the elevator will always have this same amount of 

ventilation. Conversely. sampling directly in the grain mass may 

also over- or underestimate the potential exposure hazard. 
Page 27 - Health Hazard Evaluation Report No. 83-375 

Non-uniformity of fumigant concentrations in the mass may produce 

artificially high or low levels compared to ~he total shipment. 

Additionally, these fumigant concentrations do. not represent actual 

breathing zone exposures (wi~h the possible exception of workers 

required to do sniff tests}. More likely these in-the-mass 

concentrations reflect a level of fumigant which will decrease over 

time as it is released into the surrounding atmosphere during ' . ­ handling, down to sowe residual level influenced by the grain ' 

kernels ability to absorb and hold fumigant under the influence of 

a myriad ·of envrionmental conditions. 

D. Handling of Fumigated Grain at the FGIS Inspection Laboratories: 

Problems have also been expressed concerning the bringing 6f 

fumigant laden samples into the FGIS lab for inspection. Current 

practice in h·andling fumigated grain samples is to split down the 

sample and al low the grain to air out in an open metal pan or 

container ·for four hours. Presence of fumigants (i.e., whether the 

sample has sufficiently aired out} ·is determined largely by the 

presence or absence of fumigant odor. Since not all fumigants used 

on grain have odor thresholds below hazardous exposure levels, a 

negative odor determination alone does not insure the absence of 

higher fumigant levels. Additionally, the practice · of using 

inspectors to evaluate grain odors influential in grade · determination while also inhaling low or unknown concentrations of 

fumigants, some suspect carcinogens, is a highly questionable ·practice having substantial impact on the grain industry. 

The primary route of exposure of FGIS workers to fumigants is 

considered to be inhalation. Skin absorption of fumigant vapors, 

such as carbon disulfide,16 may be possible at high 

concentrations, however the contact time FGIS workers have with 

large quantities of heavily treated grain is considered to be 

minimal. 

Basically, evaluating fumigant ·grain shipments coming into the 

elevators requires being prepared for unanticipated occurrences and 

then having the circumstances work out in such a way that fumigant 

monitoring is in progress or ·can be done while the event takes 

place. Additionally, the heightened level of concern among workers 

about fumigants and their cautious approach and/or refusal to 

process treated grain most likely contributes to a reduction in the 

overa11 number of acute fumigant exposures. Due to the n·umber of 

parties involved with a grain shipment, from the time it is · initially stored after harvest through to its final destination, 

solution of the problem requires involvement of all ~oncerned. 

E. Dust, Carbon Monoxide, and Noise Levels: 

Exposures of FGIS workers to respirable dust, carbon monoxide, and 

noise ·does not appear to be a problem, although in the case of 

noise, conducting persona1 noise dosimetry durfng periods of p·eak 

truck and lab activity would provide a better picture of noise 

exposure. Depending upon duration some noise overexposures may 

occur on a sporadic basis, since some levels were in the upper 80 

dBA range. 

,· 

···~ 
Page 28 - Health Hazard Evaluation Report No. 83-375 

VIII. CONCLUSION 

Although no personal overexposure of workers to fumigant vapors was 

documented ·during this investigation, the results of this investigation .indicate a serious potential health hazard associated with incoming fumigated grain shipments. Due to the myriad of variables influencjng 

these situations, documentation of actual worker overexposures will 

probably only happen through a fortuitous sequence of events. The 

evaluation process for sour or musty grain which requires inspectors to 

directly inhale air from grain which may have been treated with 

fumigants, including those considered to have carcinogenic potential, places the.se workers at an increased risk. The effect of chronic low 

level inhalation of fumigants such as CS2 and CCl4, singly or·in 

combination with other fumigants is unknown. 

VII. RECOMMENDATIONS 

A. Interim RecoTIITlendations 

These recommendations are intended to be amenable to more immediate 

implementation. Due to the varying circumstances affecting worker 

exposures to grain fumigants, some situations do not lend 

themselves to a simple or expedient solution. 

1. 	Workers required to open fumigated railcars should have 

self-contained breathing appratus to use during the initial 

opening of the shipment(s). 

2. 	The current 24 hour passive aeration of railcars appears adequate in maintaining exposures of railcar sampling workers 

at a low level, provided their breathing zone remains above the 

top of the railcar itself. Little exposure hazard is. expected through skin contact with the grain provided it is not wet with 

the fumigant. 

3. 	Fumigant placards should be placed on top of the cars by the 

hatch or doors in addition to being attached to the side of the 

car. (Sec 174.208 para (b) of the Hazardous Material 

Transportation Act regulations state that a railcar with 

treated lading" ••• must be placarded on each door (or as close 

as possible to the door if it is not possible to placard the 

door) ••• ". 

4. 	Workers need to be informed that the designated opening dates 

and times given on placards do not refer to the car's safety for .entry or absence of fumigant vapors after that time period. 

--·-· 

Page 29 Health Hazard Evaluation Report No. 83-375 

5. 	Workers using indicator tubes to assess fumigant concentrations 

should be trained in the use of such equipment and also be made 

aware _of its limitations. 

6. 	 Elevator managers and operators should routinely elicit 

information-on fumigant treatment of i.ncoming grain prior to 

its arriva1 at the elevator. · 

7. 	 Utilizing information available from placards and shipper reporting of fumigant usage, samples to be sniff . tested should 

be· evaluated at the grain sample surface after having been 

split and run through the dockage tester. Levels of CS2 at 

or exceeding 10 ppm or CCl~ at or ~bove 2 ppm should be used 

as criteria in deciding whether to grade the sample or allow .it 

to .stand in an open area (preferably well ventilated away from 

the main area of activity).. following the current four hour wait 

before conducting the sniff test. Fumigant level determination · should be repeated before conducting the sniff test. 

8. 	The current. policy of requiring truck drivers bringing in 

recently fumigated grain to park for 24 hours pr refusing to 

s~mple if tht fumigant is still p~esent in the grain should be 

publicized. Especially in the case of trailer ~ans, the 

sampler may. not perceive the presence of fumigant until he/she

is· inside, making a cautious approach difficult unless 

self-contained or air-line ·respiratory protection is provided. 

9. 	 All FGIS inspection labs should be evaluated concerning the 

general make-up air systems in order to in.sure sufficient air 

exchahges capable of removing low level airborne contaminants ·· (~apors). Inspection laboratories having local exhaust hoods 

should insure sufficien·t make-up air to replace what is being exhausted~ · 

10. 	Enclosure of ·the Boerner@ Divider below. the drop at the 

location where grain cascades over the internal cone should be 

provJd.ed to reduce dust and fumigant release into the operators breathing zone. Depending upon the materials used to achieve 

this, ·the a.mount of noise generated may a 1 so be reduced 

sl_ightly. 

B. 	 Long-Term Recommendations 

The fQllowing recommendations are considered appropria·te in 


addressing the -long-term solution of this problem. 


1. 	Institute a method of tracking grain fumigation during a 

shipment's passage through the grain handling system with the 

: ,;, \ 
Page 30 - Health Hazard Evaluation Report No. 83-375 

burden of assurance that a shipment does not exceed acceptable · fumigant levels upon the shipper and/or owner. 

2. 	 Develop a uniform approach mutually agreed upon and honored by 

the elevators concerning how fumigated grain shipments should 

be handled. This could serve as a deterrent to shipping - heavily fumigated grain or of shippers searching among · -:· 

elevators for those with the most lenient policies for incoming 

fumigated grain. 

3. 	An alternative method of evaluating grain for sourness· or 

mustiness should be implemented·, (See Research Needs} phasing 

out the conventional sniff test, or at least reserving the 

sniff test for contested or non-routine grading procedures. 

Changes in fumigant usage (i.e., elimination of fumigants 

associated with residual levels in grain) may alter this 

recommendat _i on. 

4~ 	 Development of a registry of grain handlers and inspectors 

along with descriptive job elements which will permit long term 

surveillance of the group tied in with occupational history. 

C. Research Needs 

Development of methods which assure quick, effective, and 

economical removal of fumigants from treated grain. 

Determination of the best approach in evaluating fumigated grain, 

to insure that a health risk to workers handling the grain will not 

occur. An example of this is the question of sampling in-the-grain 

mass versus above-the-grain mass in deciding if fumigated grain .. 

. :, 

present~ a health hazar4. ;_ 

Identification of other compounds or properties of sour or musty 

grain which can be used as a replacement for the sniff test. A 

quantitative, fast, reproducible method is highly desirable. 

Development of both equipment and strategies for evaluating 

incoming suspect grain shipments for the identification and 

quant~tation of fumigant content. 

VIII. REFERENCES 

1. Materials Transportation Bureau, 	 U.S. Department of 

Transportation. Title 49~transportation, Chapter I-materials 

transportation bureau, department of transportation; subchapter 

C-hazardous materials regulations; parts 171-177. Washington D.C: 

U.S. Department of Transportation, 1984. 
Page 31 - Health Hazard Evaluation Report No. 83-375 

2. 	U.S. Environmental Protection Agency. Title 40-protection of the 

environment, Sections· 180. 1004-1005 .exemption from the 

requirement of a tolerance. Washington, D.C.: U.S. Environmental 

Protecti on Agen·cy. 1982. 

3. 	National Institute for Occupational Safety and Health. NIOSH 

manual of analytical methods. Vol 3, 2nd ed. Cincinnati, Ohio: 

National Institute for Occupati ona1 Safety and Hea 1th,· 1977. (DHEW

(NIOSH) publication no. 77-157-C). 

4. 	 National Institute for Occupational Safety and Health. NIOSH 

manual of analytical methods . Vol 1, 2nd ed. Cincinnati, Ohio: 

National Institute for Occupational Safety and Health, 1977. (DHEW

(NIOSH) publication no. 77-157-A). 

5. National 	 Institute for Occupational Safety and Health. Criteria 

for a recommended standard: occupational exposure to carbon 

disulfide • . Cincinnati, Ohio: National Institute for Occupational Safety and Health, 1977. (DHEW publication no. (NIOSH) 77-156). 

6. 	National Institute for Occupational Safety and Health. NIOSH/OSHA

occupational health quidelines for chemical hazards. Cincinnati, 

Ohio: National Institute for Occupational Safety and Health, 

1981. (DHHS (NIOSH) publication no. 78-149). 

7. 	 National Institute for Occupational Safety and Health. NIOSH 


revised recommended · carbon tetrachloride standard. Cincinnati, 
 . Ohio: ·Nati onaf In.sti tute for Occupationa 1 Safety and ·Hea1th, 

1977. (DHEW publication no. (NIOSH unnumbered). 

8. National . Institute for Occupational Safety and Health. Current 

intelligence bulletin 25--ethylene dichloride. Cincinnati, Ohio: 

National Institute for Occupational -Safety and Health, 1978. (DHHS 

(NIOSH) publication no. 78-149). 

9. 	American Conference of Governmental Industrial Hygienists • . Threshold limit values for chemical. substances and physical agents in the work environment and biological exposure indices with 

intended changes for 1984-85. Cincinnati, Ohio: ACGIH, 1984• 

. 10. National Institute for Occupational Safety and Health. Criteria 

for a recommended standard: occupational exposure to noise. 

Cincinnati, Ohio: National Institute for Occupational Safety and 

Health, 1973. (DHEW publication no. (NIOSH) 73-110011. 

., , . ~· 
Page 32 - Health Hazard Evaluation Report No. 83-375 

11. Occupational Safety 	and Heal th Admi n.i s tration. Occupati onal 

exposure to ethylene dibromide; notice of proposed rule making.

Department of Labor: Occupational Safety and Health Administration 

1983. Federal Register 48:198:45 956-46003. I 

12. 	Occupational Safety ·and Health Administration. OSHA safety and ·! 

i 

health standards. 29 CFR 1910. 1000. Occupational Safety and 

Health Administration, revised 1983. 

13. National Institute for Occupational Safety and Health. NIOSH/OSHA

pocket guide to chemical hazards . Cincinnati, Ohio: · National 

Institute for Occupational Safety and Health, 1981. (DHHS (NIOSH)

publication no. 78-210). · · i 

i4. 	Proctor NH, Hughes JP. Chemical hazards- of the workplace. .•.J 

Philadelphia: J.B. Lippencott· Company, 1978. p 149 

15. 	National Institute for Occupational Safety and Health. 

Occupational diseases : a guide to their recognition. Revised ed. 

Cincinnati, Ohio: National Institute for Occupational Safety and 

Health, 1977. (DHEW {NIOSH) publication no . 77-181). 

16. 	Cohen AE, Paulus HJ, Keenan RG, Scheel LD~ Skin absorption of 

carbon disulfide vapor in rabbits. A.M.A. Archives of Industrial 

Health 1958; 17:164-169. ..'"'f 

17. 	Cesaro AN. The percutaneous absorption of carbon disulfide. 

Clinica del Lavoro "L. Devoto" . pp 54-56 (Translation). 

18. 	Proctor NH, Hughes JP . Chemical hazards of the workplace . Philadelphia: J.B. Lippencott Company, 1978. p 153 

19. 	American Conference of Governmental Industrial Hygienists. Supplement~l Documentation of the threshold limit .values. 

Cincinnati, Ohio: ACGIH, 1982. 

20. 	 National institute for Occupational Safety and Health. Industrial 

noise control manual . Revised ed. Cincinnati, Ohio: · National 

Institute for Occupational Safety and Health, 1978. (DHEW (NIOSH)

publication no. 79-117). 

21. 	 National Institute for Occupational Safety and Health. 

Occupational exposure sampling strategy manual. Cincinnati; Ohio: 

National Institute for Occupational Safety and Health, 1977. (DHEW

(NIOSH) publication no. 77-173). 
Page 33 - Health Hazard Evaluation Report No. 83-375 

23. 	 National Institute for Occupational Safety and Health. NIOSH/OSHA

occupational health guidelines for chemical hazards. Cincinnati. 

Ohio: National Institute for Occupational Safety and Health. 

1981. {DHHS (NIOSH) publication no. 81-123). 

Evaluation Conducted ·and t 

Report Prepared by: Steven H. Ahrenholz. C.I.H. 

Industrial Hygienist Industrial Hygiene Section 

Environmental Evaluation: Raymond L. Ruhe 

Industrial Hygienist i: 

Industrial Hygiene Section 

Virginia Behrens 

Industrial Hygi~nist 

Dennis D. Zaebst. C.I.H. 

Senior Industrial Hygienist 

Industry Wide Studies Branch 

James L. Oser. C.I.H. 

Industrial Hygienist Industry Wide Studies Branch 

On-site Sample Analyses: William J. Woodfin 

Chemical° Engineering Technical 

Systems Section 

Monitoring and Control Research · Branch 

Laboratory Analyses: Utah Biomedical Testing Laboratory 

Salt Lake City. Utah 

Arthur D. Little. Inc. 

Boston. Massachusetts 

-...... 

.. Page 34 - Heal th Hazard Evaluation Report No . 83-375 

Originating Office: Hazard Evaluations and Technical 

Assistance Branch 

Division of Surveillance, Hazard 

Evaluations, and Field St~dies 

Report Typed By: 	 Connie L. Kidd 


Clerk-Typist 


Industrial Hygiene Section 


Patty Johnson 

Secretary 

Industrial Hygiene Section 

X. DISTRIBUTION AND AVAILABILITY OF REPORT 

Copies of this .report are currently available upon request from NIOSH, 

Division of Standards Development and Technology Transfer, Publications 

o{ssemination S~ction, 4676 Columbia Parkway, Ci ncin~ati, Ohio 45226. After 90 days, the report will be available through the National 

Technical Information Service (NTIS), 5285 Port Royal, Springfield, 

Virginia 22161 . · Information regarding its availability through NTIS 

can be obtained from NIOSH Publications Office at the Cincinnati 

address . Copies of this report have been sent to: 

1. U.S. Federal Grain Inspection Service 

2. USDA Federal Grain Inspection Service - Portland Field Office 

3. American Federation of Government Emp1 oyees - Local ·3781 

4. American Federation of Government Employees - Washington D.C . 5. NIOSH, Region· X 


6~ OSHA, Region X 


.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· per.iod of 30 calendar days. 
Table I 

Affect of Sample 	Duration and· Volume on Environmental limits of Detection 

Portland Field Office Inspection Sites 

Portland. Oregon 


HETA 83-375 


.• 

Compound 

Analytical LOO 

ug per sample 

in ampling

Rate 

(lPM) 

Sampling Volume 

(L) 

Minimum Duration 

(min) 

Environmental limit of Detection in 

ug/m3 {ppb}* 

Carbon disulfide 

Carbon tetrachloride 

Ethylene dibromide 

Methyl bromide 

10 

10 

0.005 

0.40 

0.1 

0.1 

0.2 

0.05 

1 

5 

10 

48 

1 

5 

10 

48 

1 

5 

10 

48 

1 

5 

10 

24 

. . 10 

50 

100 

480 

10 

50 

100 

480 

5 

25 

50 

240 

20 

100 

200 

480 

10000 (3200) . 2000 (640) 

1000 {320) · 200 (70} 

10000 (1600) 

2000 (320} 

1000 (160) 

200 (30) 

5 (0. 6) 

1 (0.1) 

0.5 (0.06) 

0.1 (0.01) 

400 .(100) 

80 (20) 

40 (10) 

20 (4) 

*Concentrations are given in ·micrograms per cubic rneter . 	 (ug/m3) with parts per bi 1 lion · (ppb) in parentheses. . 

' •:>•' 

I 
61\ULj, J J 

Contaminant Exposure Evaluation Criteria 


Federal Grafn Inspection Service 


Portland, Oregon
 HETA 83-375 


Recommended TWA Recommended OSHAb OSHA 

1 '

.. .....

Exposure Limit Ceiling 8 hour nJA PEL Ceiling Target 

Contamf nant Formula ug/m3 (ppb)* u9/m3 (ppb)* Sourcea ug/m3 (ppb) ug/m3 (ppb) Organsd 

1 Carbon disulfide CS2 3000 (1000) 30000(10000) NIOSII C20,10 (20000) 93061 (30000) central nervous 

systems .peripheral 

nervous system. 

cardiovascular system 

2 Carbon monoxide C 0 4()000 (35000) 228570 (200000) NIOSH 55000 (50000) cardiovascular 

system, lungs, blood, 

central nervous system 

3 Carbon tetrachloride CCl4 - 12600 (2000)C NIOSH 62857 (10000) 157143 .(25000) cen tra1 nervous 

system, eyes, lungs, 

1her, kfdneys 4 C'hl oroform CHCl3 - 9714 (2000)C NIOSH - 240000 (50000) ·11ver, kidneys, 

heart, eyes, skfn 

5 1,2-Dfchloroethylene ClCHcCHCl - - - 790000 (2000000) respfratory system, 

eyes, central nervous 

system 

6 Ethylene dibromfde CllzOrCH2Br 345 (45 )C 1000 (130) N10Slf 767 (100) 383€ (500) . respiratory system, 

liver, kidneys, skfn, 

eye~ 

7 Ethylene dichloride ClCH2CH2Cl C - NIOSH 202000 (50000) 404082 (100000) kidneys, liver, eyes, 

skin, central nervous 

system 

Grain dust - 4000 . - ACGIH respiratory system 

t·lethy1bromide CH3Br 20000 (5000) - ACCIH - 80000 (20000) central nervous 

system, respiratory 

system, lungs, skin, 

eyes 

Noise+ 85dBA/8 hrs 115dBA/,12hr. ACGIH 90dBA/8 hrs 115dBA/.25hr auditory system 

•: 	 Concentrations have been presented in microgra~s per cubic ireter (ug/m3) and parts per hillion (ppb) fn parentheses. To~convert~to 

milligrams per cubic meter (mg/m3) or parts per mfllfon (ppm) divide lfs~ed value by 1000. 

a: 	 NIOSH sources cf ted are, fn ·order ot'. appearance, references 5, 6, 7. 6, - fnterna 1 NIOSH memorandum, a. 10~ ACCIH criteria are taken from 

reference 29. 

b: The OSHA standard for ethylene dibromide presented here is the proposed limit, 11. See Appendix B. All other OSHA standards are from 29 · CFR. 1910 (reference 12 )• 


c: 	 Denotes compounds considered to have carcinogenic potential in man. NIOSH recommends these substances be treated as suspect occupational carcinogens. No recommended exposure limit, other than ~afntafning levels as low as feasible is given for ethylene dichloride. 

d: See Toxicity Discussion. Information presented here from reference 13. 


+: Noise evaluation crfterfa is given for a continuous srund level • 


1.. 	 .. ,. ., ..... :... \.... •-i1 I •i •"'" 

• ' 

. 
Table III 

fumigant Exposures of Federal Grafn Inspection Service Workers 

Portland Field Office Inspection Site 


Portland, Oregon


HETA E3-375 


• 	

Noveni>er 15-18, 1983 


~oncentraiion 1n u97m3lpp6J~

Date Elevator Job Duration (min) t2R4ffr2 fS2 ccl4 

11/15 Colunbia Grain Truck Supler 320 trace NO NO 

11/15 Columbia Grafn Truck Sampler 293 trace NO ND 

11/15 'col uni>fa Grafn Truck Inspector 319 10 (1.3) 130 (41 ). 430 (fie) 

11/H> Columbfa Grafn Truck Inspector 295 . trace 130 (41) NO 

11/15 Bunge Elevator Trude Sall)I)ler 388 12 (0.16) ND ND 

11/15 Bunge Elevator Truck ·Inspector 386 ' 43 (0.56) ND 570 (90) 11/15 Bunge Elevator Truck Inspector 365 160 (21) 90 (29) 590 (94)

11/16 Coluni>fa Grain Truck Sampler 387 NO 310 (101) 1570 (250)

11/16 Co1uni:>111 Gra.fn Truck .Sampler 373 trace 100 (32) 330 (53)

11/16 Columbia Gratn Track Sampler 340 NO 2280 (738) 12350 (1960)

11/16 Coluni>ta Gratn Truck Inspector 389 trace 260 (85) 660 (105)

11/16 Columbia Grafn Truck f nspector 402 trace 410 (131) 1020 (161) · 11/16 Bunge Elevator Truck Sampler 386 1.E (0.23) ND ND 

11/16 Bunge Elevator Truck Inspector 395 2.5 (0. 32) HD 560 (Ee) 

11/16 Bunge Eleva tor Truck Inspector 400 1.7 (0.22) 80 (26) 270 (43) 

11/16 Cargill Elevator Truck Inspector 392 ND NO ND 

11/16 Cargill Elevator Track Inspector 464 trace ND ND

11/17 Columbia Grafn Truck Sampler 376 2.6 (0.34) ND ND 

11/17 Coluni>fa Grafn Truck Sampler ·374 · 2.3 (0.29) 120 (38) ND 

11/17 Colu1r.bfa Grafn Truck Inspector 365 2.7 (0.36) 290 (93.) 640 (102) 

11/17 Bunge Elevator Truck Sa11.p ler 442 2.8 (0.36) ND · NO 

11/17 Bunge Eleva tor . Truck Inspector 435 6.0 (0.76) ND ND 

11/18 Cargill Elevator Truck Sampler 233 trace tlD ND , 11/lE Cargfll Elevator Truck Inspector 244 NO ND ND 

11/18 Coluni>fa Grain - Rafl Car Headspace• 15 ND 	 8800 (2836) 32500 (5167) 

OSHA 8 hour 	nlA PEL u in ug7m3lpp6) 161 uooJ 62040(20000 J ·62857(10000 J 

Analytical Lfmft of Oetectfon in ug per sample 	 0.01 3 10 


+toncentrations are gfv~n 1n micrograms per cu6fc meter (ug/m3) with parts per 61llion (pp6J given 1n parentheses.


NO indicates sample concentration was below the gfven limft of detection for that substance. 


Trace denotes ethylene dfbromfde samples fn whfch the compound was fdentiffed as befng pr.esent but was below a . 
 concentration whfch could be analytically quantified or less than 50 nanograms but gre1ter than 10 nanograms per sample Fumigants sampled'were: . f _ ·· C2ff48r2 c ethylene dfbromfde 

CS2 c carbon disulfide 

CCl4 c carbon tetrachloride 

*The rail car fn which thfs sample was taken was known to contain fumigated grafn. 1 The top hatches had been propped open for approximately 70 to 90 minutes prior to sampling 

•• 	Values are the 8 hour time weighted average (TWA) permfssfble exposure lfmft 

(PEL) Reference 12 

The ethylene dfbromfde value ts taken from OSHA's proposed rule. 

..:..,. .. -· . • ... ~.1 ...... ..

Table -IV 


Exposure of Federal Grain Inspection Service Workers 


to Ethylene D1bromide, Carbon Disulfide, and Carbon Tetrachloride 


Portland Field Office Inspection Site 
 -Portland, Oregon 


HETA 83-375 


April 9-13, 1984 


Concentration in ug/m3 Ceeb )+_______ 

Date Elevator Job Duration (min) C2H4Br2 CS2 C_Cl4 CH3Br 

4/09 Columbia Grain 	 Truck Sampler 433 O.85 (0.11) ND 

Truck Sampler 410 0.92 (0.12) ND 

Truck Inspector 426 Trace ND 

Truck Inspector 413 ND -tio 

ND 

ND 

ND 

ND ' 

Track Sampler 136 ND ND 

Track Insp~ctor 245 ND ·ND 

Track Inspector 243 ND ND 

ND 

ND 

ND · 

ND 

4/09 Cargill Elevator 	 Truck Sampler 417 0.62 (0.08) ND 

Truck Inspector 431 ND ' ND 

ND 


MD 


Track Sampler 342 - 0.56 (0.07) ND 

Track Inspector 427 ND ND 

Track Inspector 453 ND ND 

_585 (93) 

ND 

ND 

ND 

Ship Inspector 412 	 ND ND ND 

4/10 · - Columbia Grain 	 Truck Sampler 399 - ND ND 

Truck Sampler 422 Trace ND 

Truck Inspector 400 ND ND 

ND ND 	

ND 


ND 


ND 


ND-

-t::-- <:) / -, 	 .. ...-.... .... ~ I 

...._ 	

Track Sampler 210 ND ND. Track Sampler 222 ND ND 

Track Inspector 273 ND ND 

Track Inspector 274 ND ND 

Track Inspector 260 - ND ND 

ND 

ND 

ND 

ND 

ND 

ND 

ND 

Continued 

' ..;,;,,;;.... 

­

­
Table IV 


Continued 


Date 

4/10 

Elevator 

Bunge Elevator 

Job 

Truck Sampler 

Truck Inspector 

Duration 

Concentration· in ug/m3 <eeb)~ 


(min) t2H4Br2 CS2 CCl4 CH3Br 


376 

384 

Trace ND NO 

NO NO NO 

Track Sampler 

Track Inspector 

Track Inspector 

422 

· 424 

414 

NO ND NO 

ND ND . NO 

ND . ND ND 

NO 

4/11 Bunge Elevator Truck ·Sampler Truck Inspector 425 

457. . ND ND ND 

ND ND 184 (29) 

Track Sampler 

Track Inspector 

Track Inspector 

390 

484 

454 

NO ND ND 

NO ND NO 

NO ND ND 

.NO 

4/11 Cargill Elevator Truck Sampler 

Truck Inspector 

Truck Inspector 

407 

4'32 

386 

Trace · ND 2457 (391) 

NO ND 694 ( 110) 

NO · ND NO 

Track Sampler 

Track Inspector · Track Inspector 

351 

406 

410 

ND NO ND 

NO ND ND 

ND ND ND 

ND 

4/12 Columbia Grain Truck Sampier 

Truck Sampler 

Truck Inspector 

Truck Inspector 

411 

377 

414 

392 

3.8 (0.49) ·ND NO 

NO ND 292 (46) 

NO NO ND 

ND -ND ND 

Track Sampler Track Inspector 

Track ·Inspector 

363 

417 

·389 

ND ND ND 

NO NO ND 

Trace . ND ND 

ND 

4/12 Cargill Elevator Truck Sampler Truck Inspector 409 

444 

0.60 (0.08) NO 4·99 (79)

ND NO ND 

Truck Inspector 435 ·. ND ND ND 

'\... Continued ..":., , .. \ 

" ' •l ! 1 •H! ,.. ... . .,.,.. . .,. i. ­ ' 'l!T' l' .- . 
Table IV 


Continued 


Concentration in u~/m3 Cee~)~
 Date Elevator Job Duration (min) C2H4Br2 CS2 CCl4 CH3Br 


Track Sampler 261 	 · Trace ND 1172 (186) ND 

Track Inspector 411 	 ND ND 487 (77)

Track Inspector 409 	 ND ND ND 

4/13 Bunge Elevator 	 Truck Sampler 499. ND ND NO 

Truck Inspector 511 NO ND 230 (37) 

Truck Inspector 526 · ND ND 184 (29) 

OSHA 8 hour TWA PEL* in ug/m3 (ppb) 767 (100) 62040 (20000) 62857 (10000) 80000 (20000)

Analytical Limit of Detection in ug per sample .005 10 10 0.4 

 + Concentrations are given in micrograms per cubic meter (ug/m3) with parts per billion (ppb) in parentheses 

D N indicates sample concentration was below the given analytical limit of detection for that substance 

Trace denotes ethylene dibromide samples in which the compound was identified as being present but was below a conc

could be analytically quantified or less than 0.023 ug per sample but greater than 0.005 ug per sample. 

entration which

indicates worker exposure to methyl bromide wasn't determined. 

Fumigants sampled were: 

C2H4Br2 = ethylene dibromide 


CS2 c Carbon disulfide 


C~l4 = Carbon tetrachloride 


CH3Br = methyl bromide 


* 	 Values are the 8 hour time weighted average (TWA) permissible exposure limits (PEL) (reference 12). The value for ethylene 

dibromide is taken from OSHA's proposed rule. (See Ref 11.) · 

._ 

'"1·• . •.• 	 .-,. . ~-- . 
Table V 


Truck Samplers Carbon Monoxide Exposures 


Portland Field Office Inspection Sites 


HETA 83-375 


April 9-11, 1984 


Duration** 

Date Work Location* ·# of trucks+ {min) Concentration*** -------------- 4/9 · Columbii Elevator, truck 

sampling platform 

47 431 Negligible

4/9 	 Columbia Elevator, truck 

sampling platform 

412 Negligible 

4/9 .Cargill Elevator, truck 

sampling platform 

30 _512 Trace 

4/10 Columbia Elevator, truck ·sampling platform 

2S .400 Negligible

4/10 	 Bunge Elevator, truck 54 437 Trace 

sampling platform 

4/11 	 Bunge Elevator, truck 54 428 Negligible 

sampling platform 

* 	 All samples are personal breathing zone exposures for truck samplers doing grain sampling at . the truck sampling platform 

** 	Duration is given in miriutes. Pumps were collected (with the exception of the third value), 

during the worker's lunch period. 

***Drager® long term carbon monoxide tubes were used, CH28121, lot #0524199, expiration date 

March 1986~ . Sample volumes were between- 5 and 8 liters~ providing a lower environmental detection 

limit of 5 to 10 parts per million. Trace denotes a minor brownish discoloration at the 

beginning of the indicating layer but no concentration could be obtained from the tu~e. 

+ 	 Number of trucks is a total for the day, as reported by the worker. 
1aolc V! 

Short-Term Fumigant Sa~ples for Carbon Disulfide and Carbon Tetrachloride 

.Poriland r;eld Office Inspection Sites 

Portland. Oregon . HETA 83-375 

April 11-13, 1984 

Railroad Car 

ID Nuni>er 

Date 

Fumf gated 

Date Grain Sample Sample furr.i9ant Concentration fn ?f!/m3~ 

Sampled Sample Location "Aerated" Type Durati en tar6on Dlsu1ilde tar6on "etrac or de 

UP 73909 3/30/84 4/ll/C4· Bunge. above grain, X CT 15 1.3 ( 0.43) 4.7 (0.74) 

fn car DG 5 0.90 ( 0.29) 

Bunge. fn-the-mass, X CT 12 683 ( 220)~ ·1750 (278) 

fn car BG 5 19.8 (63.9) .../ 

UP 73909 3/30/84 4/11/84 Bunge, fn-the-mass, X CT · 12 7.5 (2.4) <0.83 ·(<0.13) 

1n car, back-up sample 

· _Bunge, grain surface, X CT 5 4.o· .<·1.3) ·10 (1.6) 

after dockage tester BG 5 1.9 ( 0.61) 

UP 73909 3/30/f,4 4/11/84 Bunge, BZ sample, X CT 7 <1.4 (<0. 46) <1.4 (<0. 23) 

track sampler. top llG 5 (4. 9) 

of car 

UP 73909 3/30/84 4/11/84 · Bunge, grain surface, X CT 10 1.0 (0. 32) 5.0 (0.80) 

lab sample prfor to BG 5 (0.58·) 

being split 

UP 73909 3/30/f,t, 4/11 /84 Bunge, 82, personal X CT 8 <1.2 (<0.40) · <1.2 (<0.20) 

exposure during gr~in 

inspection. Grain 

inspector. 

UP 7390~ 3/30/84 4/12/E4 Bunge, dumping grain. X CT 5 <2.0 (<0.64) <2.0 (<0.32) 

at grain' stream BG 5 (<l) 

UP 7390!1 3/30/84 4/12/84 Bunge, grai~ .surface, X CT 6 1.7 (0.54) 10 (1.6) 

grafn sample froni auto- BG 5 (0.3) 

sampler 

(Continued) 

, .. 

-·-., 

,, -·-· 

','• .; ~ 

··r• . ,. . ·'tn 
(Continued) 

Railroad Car Date Date Grain Sample Sample Fumigant ·concentration in m9/m3~

ID Number Fumigated Sampled Sample Location "Aerated" Type Duration Carbon Disulfide Carbon Tetrac or de 

UP 73735 4/ 2/84 4/11/84 Bunge, above grain, X CT 14 1. 4 ( 0.46) 5. 7 (0. 91) 

in car BG 5 6.8 ( 2.2) 

Bunge, in-the-mass, x CT 16 412 ( 133) 11 1562 (24~) 

in car BG 5 6e c 22) 

UP 73735 4/ 2/84 4/11/84 Bunge, in-the-mass, X CT 16 0.63 (0.20) <0.63 (<0.10) 

in car, back-up sample 

Bunge, grain surface, X CT 5 2.0 ( 0.64) 4.0 (0.64) 

after dockage tester _ BG 5 1.2 ( 0.4) 

UP 73735 4/ 2/84 4/11/84 Bunge. BZ, track X CT 6 <1.67 (<0.54) <1.67 (<0.27) 

sampler, top -of car BG 6 (0.21) 

UP 73735 4/ 2./84 4/11/84 Bunge, grain surface X CT 10 1.0 (0 . 32) 5.0 (0.80) 

lab sample prior to BG 5 (0.35) 

being split 

UP 73735 4/ 2/84 4/11/84 Bunge, BZ, personal X CT 7 1.4 (Q.46) <1.4 (<0.23) 

exposure during grain 

inspection, grain inspector 

UP 73735 4/ 2/84 4/12/84 Bunge, dumping grain, X CT 5 <2.0 (<0.64) <2.0 (<0,32) 

at grain stream BG 5 (<1) 

UP 73735 4/ 2/84 4/12/84 Bunge, grain surface, X CT 8 <1.2 (<0.40) 2.5 (0.40) 

grain sample from auto- BG 5 (<l) 

sampler 

(Continued) 

( ~ 

!~ , . ..,1.. .. . • '. .. ~ ., 
(Continued') 

Railroad Car 

10 Number 

UP 22293 

Date 

Fumigated 

Date 

Sampled 

Grain 

Sample Location "Aerated" 

Sample 

Type 

Sample 

Durati on 

Fumigant Concentratio.n in m9/m3~

tarlion Dtsu1ilde Caroon Tetrac or de 

4/ 1/84 4/12/84 Bunge, head space 

prior to fully 

CT 

BG 

6 

5 

137 ( 44) 233 (37) · 1.0 ( 0.34) 

opening car lfd 

UP 22293 4/ 1/84 : · 4/13/84 Dunge, above gra1n. X CT 15 <0.67 (<0.22) 1. 3 (0.21) 

1n car 

UP 22293 4/ 1/84 4/13/84' · Bunge·, in-the-mass, . X 

in car 

CT 16 . 401 ( 155)* 1250 (199) 

UP 22293 4/ l/84 4/13/F,4 Bunge, in-the-mass, X CT 16 <0.63 (<0.20) <0.63 (<0.10) 

in car, back-up sample 

UP 22293 4/ l/84 4/13/84 Cunge, dumping grain, X CT 6 <1.7 (<0.54) <1.7 (<0.27) 

at grain ·stream BG 5 (0.50) 

UP 22293 4/ l/G4 4/13/U ·Bunge, unsplf t X 

fn1tia1 grain sample 

CT 

BG 

15 

. 5 

0.7 ( 0.21) 2.0 (0.32) 

6. 2 ( 2) 

fn lab 

UP 22293 4/ 1/C4 4/13/84 Bunge, splitting of X CT l <10 ( <3. 2) <10 ( <l. 6) 

grain sample, in lab, 

personal sample 

UP 22293 4/ 1/64 4/13/84 Dunge, BZ, graf n X CT l <10 ( <3.2) <10 ( <l.6) 

inspector, sniff 

test during inspection 

(Continued) 

~ --\ · -· 

' .... 1 · i, - .. 
.., __-----· 

(Continued) 

Raf lroad Car 

JD Number 

UP 14546 

Date · Fumigated 

Date 

Sampled 

train 

Sample Location "Aerated" 

Sample 

Type 

Sample 

Duration 

6** 

. 5 

Fumi9ant Concentration in m9/m3~ 

Carbon Disulfide Carbon Tetrac or de 

233 ( 75) . 400 (64) 

22 ( 7.2) 

4/ 1/84 4/12/84 Bunge, head space · prior to fully 

CT 

BG 

opening car lfd 

UP 14546 4/ 1/84 4/13/84 Bunge, above grain, X 

in car 

CT 

BG 

15 

5 

173 (56 )* 2667, (424)* 

(3) 

UP 14546 4/ 1/84 4/13/84 . . Bunge, in-the-mass, X 

in car 

CT 

BG 

15 

5 

413 ( 133)* 1533 (244) 

65 ( 21) 

UP 14546 4/ 1/84 4/13/84 Bunge·, .in-the-mass X CT 15 <o.6°? <<o.22r <0.67 (<0.11) 

in car, back-up sample 

UP 14546 4/ 1/84 4/13/84 Bunge, dumping X 

grain, at grain 

CT 

BG 

6 

5 

1.7 (O~ 54) 5.0 (0.80) 

(5) 

stream 

UP 14546 4/ 1/84 4/13/84 Bunge, unspli t X CT 18 1.1 ( 0.36) 3.3 (0.53) 

initial grain sample BG 5 9.3 ( 3) 

fn lab 

UP 14546 4/ l/84 4/13/84 Bunge, splitting of X CT 2 <5.0 (<1.6) <5.0 (<0.80) 

grain sample, 1n lab, 

personal exposure 

UP 14546 4/ 1/84 4/13/84 Bunge, BZ, grain X CT l <10 (<3.2) <10 (<1.6) 

inspector, sniff 

test, during inspection 

(Continued) -:::

- ·-. 

• ....-

,= 

:..· 
(Continued) 

Railroad Car 

ID Number 

UP 76314 

Date 

Fumigated 

Date 

Sampled 

Grain Sa1J>ple 

Sample Location "Aerated" Type 

Sample 

Duration 

Fumf gant Concentration 1n m9/m3~

tar6on Dhu1Hde ·tar6on Tetrac or de 

4/ ­5/84 4/12/84 Bunge, head space CT 

prior to fully .BG 

opening car lid 

7 

5 

214 ( 69)* 1157 (184)* 

17 ( 5.4) 

UP 76314 4/ 5/84 4/12/84 Bunge, headspace CT 

prior to fully opening 

car lid, back-up ·sample 

7 <1.4 (<0.46) <1.4 (<0.23) 

UP 76314 4/ 5/84 4/13/84 Bunge, above grain, X CT 

in car BG 

15 

5 

1.3 (0.43) 8.7 (1.4) 

(<1) 

UP 76314 4/ 5/84 4/13/84 Bunge, in-the-mass, X CT 

in car BG 

15 

5 

353 ( 114 )* 4333 (689)* 

776 ( 250) 

UP 76314 4/ 5/84 4/13/84 Bunge, in-the-mass, X CT 

in car, back-up sample 

15 800 (258)* 2200 (350) " 

UP 76314 4/ 5/84 4/13/84 Bunge, dumping X CT 

grain, at grain station BG 

6 

5 

<1.7 (<0.54) 5.0 (O.EO) 

(<1) 

UP 76314 4/ 5/64 4/13/84 Bunge, unsplft X CT 

initial grain sample BG 

fn lab 

18 . 

5 

47 ( 15) 52 (8 . 2) 

(N. O.) 

UP 7t314 4/ 5/84 4/13/84 ~unge, BZ, splitting X CT 

of grain sample, 1n 

lab, personal sample 

2 <5.0 ( <I. 6) <5.0 (<0.80) 

UP 76314 4/ 5/84 4/13/84 Bunge, BZ, grain X CT 

inspector, sniff test 

during inspection, 

(Continued) 

1 <10 (<3.2) <10 (<J.6) 

.­

.. •·~· :" l···· ' ....,."' ... ....,; ~ .... 
(Continued) 

Raf lroad Car Date Date Grain Sample Sample Fumigant Concentratfon in m9/m3~

ID. Number Fumigated Sampled Sample Location "Aerated" Type Duration Carbon Disulfide Carbon Tetrac or de 

BN 452278 4/ 5/84 4/12/84 . Cargill. head space CT 7 1014 ( 327)* 2857 (455) 

prfor to fully BC 5 · 354 ( 114) 

opening car lid 

B~ 45,278 4/. 5/84 4/12/84 Cargfll, headspace CT 7 13 (4. 2) 1.4 (0.23) 

prfor to fully opening 

car. lid, back-up sample 

UTCX 44256 4/ 5/84 4/12/84 Cargill, head space CT 7 671 ( 2Cl )* 7143 (1136)* 

prfor to fully BG 5 695 ( 224)

opening car lid 310 ( 100) 

UTCX 44256 4/ 5/84 4/12/84 Cargill°, headspace CT 7 771 (249) 400 (64) 

prior to fully opening 

car ltd, back-up sample 

PLCX 22916 Unknown . 4/13/84 Cargill, in-the-mass, CT s <1.1 (<0.36) <1.1 (<0.16) 

tn car BG 5 (470) 

(385) I 

PLCX 22916 Unknown 4/13/84 Cargill, grain surface, CT 20 6.0 ( 1.~, 26 (4.1) 

ffle sample (7) · BG 5 9.3 ( 3) 

SLSF 86565 Unknown 4/13/84 Cargfll, above grafn CT 12 5.0 (1.6) 27 (4 . 1) 

fn car BG 5 (0. 75) 

SLSF 86565 Unknown 4/13/84 Cargill, above grain, CT 12 7.0 ( 2. 3) 24 ( 3~8) 

file sample in lab BG 5 2.3 (0.75) 

split once 

(Contf nued) 

.. ... •· 1 ··· r ··!• ,. •• ·~ ·•t···· 
Explanatory l!otes: ·sarr.ple Descriptors 

Date Fumigated obtained from placard. 

Sample locations are defined as follows:. . above grain: samples obtained about 6 inches to 1 foot about the grain surface 

in-the-mass: sampling. train inlet submerged 1n the grain 

grain surface: samp11 ng train opening located at the grain surface to s11 ghtly above (approx. 1/2 - 2 inches). 

head space: sample of space above grain prior to fully opening lids on car. See Methods and Materials Section, back-up sample: sorbent tube sampling done with two tubes in series. These samples designate the second tube of 

samples demonstrating break-through on the first tube. (See Methods and Materials Section). 

Grain Type: Soft White Wheat 

Grain "Aerated" denotes ~ra_in held fn the railroad car and standing for 24 hours wfth the hatch doors (lfd) open. 

Sample Type ·denotes whether the sample was a bag sample (BG) analyzed in the field using a portable gas chromatograph or.­ a charcoal tube (CT) sample analyzed fn the laboratory. BZ denotes a breathing zone sample obtained for a worker~ 

Sample Duration for CT samples is given in minutes. bag .samples were run until -mylar bag was filled. or about S minutes (See Methods 

and Material · Section). 

Explanatory llotes: Fumigant Concentrations 

Fumigant Concentrations are given in milligrams per meter cubed Cmg/m3) with the parts per million value (pp~) in 

parentheses. · 

< Indicates concentrations were below the analytical limit of detection. The value given in these instances is the 

calculated environmental limit' of detection for that sample. 


. .
 * Breakthrough occurred on tube - more than 302: of the analyte was found on the back-up section of the charcoal tube. ** approximate sample duration *** back-up section lost fn analysis.

' '· 
) ~ . ...:...• 

., 


I

I

I

I
Table VII 


Sarr.ple Break-down and Statistics for Short-term 


Fumigant Sampling 
 . Portland Field Office Inspection Sites 


Portland, Oregon 
 ffETA 83-375 


April 11-13.1964 


Sample Description Codes (see . key below) 

A E C D E F G fl I J 

fta11road l:ar [1eva £or 

UP 	 73909 Bunge X X X X X X X X 

UP 	 73735 Bunge X X X X X X X X 

UP 	 22293 Bunge X 'X X X X X X 

UP 	 14546 Bunge X X X X X X X 

UP 	 76314 Bunge X X X X X X X 

BN 	 45227E Cargi 11 X 

UTCX 44256 Cargill X 

PLCX 22916 Cargi 11 	 X 

SLSF 86565 Cargill 	 X 

Humber of samples (n) !', 5(6)• 5(6)• sn 5 zn Z** z» .J•• 50 -·-------------------------------·---------------------------------------------------·----------­ Geometric mean (ppm) 	 CS2 . 116 1.5 147 0.65 


CC14 186 2.4 297 0.98 


Geomet. Std. Deviation CS2 2.5 8.2 1.3 5.8 


CCl4 4.0 19 1.6 3.5 


Range . (ppm) 	 CS2 44-327 ND-56 ND-155 ND-0.54 0.21-15 ND-0.54 0.64-1.3 ND ND ND-0.46 

CCl4 37-1136 0.21-424 ND-6E9 ND-0.80 0.32-8.2 0.40-1.6 0.64-1.6 ND ND ND 

' \ 

key to Sample Location and Identity: A: 	 Ra11 car head space 

B: 	 Above the .grain in the rail car 

C: Jn-the-n,ass. in the roil car 

D: At the grain stream during dumping 

E: 	 At the grain surface. in the lab. for the unsplft sample. 

F: Grain surface of a 	lab sample obtained from the automatic sampler. 

G: At the grain surface after the grain has run through the dockage tester. 
 ·H: Breathing zone sample for a track sampler while on top of the rail car. 


1: 	Breathing zone sample for a worker splitting a grain sample 1n the lab. 

J: 	Breathing zone sample for a grain inspector during the grain inspection 


(i.e., sniff test). 


~ote: See Table VJ for data on individual samples. 


X - Means that sample had break-through, values presented are lower than the actual concentrations. 


-w - Calculation of statfstfcal values excluded non-detected to remafn consistent with the way other 


statistical values were obtained elsewhere in this report. Numbers in parenthesis fs the total 

number of samples taken, first number is the points used fn calculating the statistics. 

•• - l·\eans were not calculated 1f over SOS _of the samples were non-<letectahle or due to Sll'all sample she. ··. 	 . . ·• ••• - · t .. 	 ..,. ,. ' ··- • ~-.1. • .,' , ...... 
Table VIII 

Results of Area Respirable Dust Samp1ing 

Portland Field Office Inspection Sites 


Portland, Oregon 


HETA 83-375 


April 9-12, 1984 

Date Elevator 

Duration 

Sample location (min) 

Vol 

(L) Dust Concentration in mg/m3 

4/9 Columbia 	 Sfde. of Boerner~ 495 

divider (splitter), 


truck grain inspection 


lab 


792 0.37 


4/9 Columbia 	 Side of Boerner® 425 

divider, track 


(railroad car) grain 


inspection 1ab 


680 0.09 


4i9 Cargill 	 Sample preparation 524 

room, grain inspection 


lab 


865 0.05 


/ 

4/9 Cargill 	 Technician preparation 486 

room,. grain inspection 


lab 


802 0.05 


4/10 Columbia 	 Truck grain inspection 502 

lab 


874 0.20 


4/10 Columbia 	 Track grafn inspection 519 895 0.·08 

. 4/10 Bunge Truck sampling catwalk 485 829 	 0.02 

4/10 Bunge 	 Si de of Boe.rner® 487 

divider, grain 


inspection lab 


816 · 0. 18 


4/11 Bunge 	 Truck sampling catwalk 514 874 0. 05 

4/11 Bunge Side of ·Boerner® 535 

.. divider. grain
 inspection lab 
 . Continued
 . 

904 0.29 


.... .. 	 •fl .. ... 
Table VII I 

Continued 

Duration Vol 

Date Elevator Sample Location (min) ( L) Dust Concentration in mg/m3 

4/11 Cargi 11 · Side of Boerne·r® 510 867 ++ 

~ivfder. grain 

inspection lab 

4/11 Cargill Grading Lab 513 872 0.06 

4/12 Columbia · Track · grain 495 · 842 0.06 

i-nspection lab 

4/12 Columbia Truck grain 480 816 0.10 

inspection lab 

4/12 Cargill . Grain inspection Lab 511 884 0. 05 

4/12 Cargill Side of Boerner® 510 880 0.06 

divider. grain 

inspection lab 

4/13 Bunge Truck sampling catwalk 542 921 0.07 

4/13 Bunge Grain inspection 551 937 0.14 

"'

Evaluation Criteria:· OSHA Nuisance Oust - Respirable Fraction* 5.00 fug/m3 

++No weight grain recorded for this sample. 

* Respirable nuisance dust evaluation criteria given. No silica determination was made on these samples. 

ACGIH recommends a· total grain dust exposure limit of 4 mg/m3, however their ·limit is not applicable 

to this data since it represents on11 the respirable fraction of the grain dust. 

S"•l I 

:". 
....•' 

·• ) 

.• 

Table IX 

Noise Level Measurements 


Portland Field Office Inspection Sites 


Portland, Oregon
 HETA 83-375 


April 9-13, 1984 


A scale 

Allowed Time 

(hrs)** 

_ 6.1 

10.6 

27.8 

27.8 

8 

13.9 

16 

10.6 

128 

Date 

Sound Level Measurement* 

Noise Source Description Location A scale C."scale 

4/9 

4/10 

4/10 

Truck sampling area, .Cargill 87 90 

truck engines 

Grading Area Cargill Lab 83 83 

Sample Preparation Area Cargill Lab 76 80 

Track sampling, rail yard Cargill 76 88 

Near Boerner Divider® Columbia lab 85 85 

in tra~k inspection lab+ 

Between divider and · Columbia Lab 81 81 

dockage · tester in track 

inspection lab+ 

Inspection lab equipment. Bunge Lab 80 85 

operating, general area 

Truck sampling area, Bunge 83 88 

two trufkS pul l_ing in 

Jrack sampler, out on Bunge 65 74 

cars in rail yard 

(Continued) 

,, . ..·. .. j ., :"!' i ..,. ,.,:.

­
Table IX 

(Continued) 

... ··-··, . \ '\ 

•:.. _'.·\ 

Date Noise ~ource Description Location · Sound level Measurement* A scale C scale 

A scale 

Allowed Time 

(hrs)** 

4/11 

4/11 

4/12 

Near f1rst divider 1n lab+ 

Near second divider in 

lab+ 

Back of _dockage tester 

Railyard, railcar 

sampling area 

Truck sampling area 

Sample Preparation Area 

(during full operation) 

Grading Area 

(during full operation) 

Truck sampling platform 

(while sampling truck) 

Railyard, railcar 

samp11 ng area 

Truck sampling platform, 

trucks idling 

Bunge 

Bunge 

Bunge 

Bunge 

Bunge 

Cargi 11 Lab 

Cargill Lab 

Cargill 

Cargi 11 

Columbia 

86 86 

82 · 82 

80 84 

72 76 

76 84 

74 76 

66 73 

77 87 

75 84 

76-78 82-84 

. 

7.0 

12. l 

16 

48.5 

27.8 

36.8 

11.4 

24.2 

.32 

27.8-21.1 

(Continued) 

..,, .,. 
Table IX 

(Continued) 

scale 

Sound Level Measurement* · Allowed Time 

Date Noise Source Description Location A scale C. scale (hrs)** 

\ 

4/12 Inspection lab (general) Cargill Lab 75 85 32 

Railyard, railcar Cargill 70 . 88 64 

sampling area. 

Truck sampling platform Cargi 11 · 75 83 32 

area 

4/13 Truck sampling platform, Bunge 76 85 27.8 

trucks 1 dli ng 

Evaluation Criteria: See Table I - ACGIH 85dBA - 8 hour workshift, continuous noise. 

Measurements obtained with a General Radio Type II sound level meter, Model 1565B, 

Serial No• . 4308. Unit was calibrated daily • . 

*Sound level meausurements were ·obtained on both the A scale, representing the noise 

level as perceived by the human ear, and the C scale which does not apply any weighting 

factor to the different frequencies. 

+Noise levels are influenced by the grain being run through the dividers. 

**This column presents the allowed duration (in hours) of exposure to this nofse level 

assuming the noise fs continuous and that an exposure lfmit of 85dBA over an eight-hour · workshift is applied. The formula used fs : allowed time= 480 min 

20.2 ([A-N) · 

LA= measured noise level in dBA 

N = ·a-hour noise limit · This value is divided by 60 to obtain hours. 

Source: NIOSH Industrial Noise Control Manual, Revised Edition, reference 20. 
,Figure I 


Carbon Disulfide Fumigant Levels Obtained From Rail Car Grain Shipments 


Portland Field Office Inspection Sites 


Portland, Oregon 


HETA 83-375 


ppm of Carbon Disulfide 

Car Number and 

Sample Description* . OP 73909 --- · r - - - ..,...

. 

Above grain. in car 0.43 ppm .·. ' 

In-mass, in car I 220 ppm+** 

OZ of grain inspector during inspection - ND** .. 

I 

UP 73735 

0 . Above grain, in car .46 ppm 

In-mass., f n car I 133 ppm+ 

BZ of grain inspector ' 

during 1nspectfon 0.46 ppm 

UP 22293 ' 

·Car head space before I 44 ppm 

opening 

Above grain, 1n car ND 

In-mass, fn car I 155 ppm+ 

BZ of grafn inspector during inspection ND 

. UP 14546 

Car head space, I 1s ppm 

before opening 

Above grafo, fn car J 56 ppm 

In-mass, 1n car . I 133 ppm 

\ Continued .. ) 

... :, 
Figure l Continued 


Z o

durin

UP 7

Car 

befo

Abov

In-m

BZ o

duri

BN 4

Car 

befo

utcx 

Car 

befo

D

. 

·

·

f

6

h

r

e

n

5

r

h

r

grain inspector 

g inspection ND

314 

ead space. 69 P 

e opening ' 

grain. in car u.43 ppm 

' 114 ppm+ ass. 1n car 

f grain fnspector

g fnspectfon ND 

. 2278 

head space. > 

327 ppm+ e opening . 
 44256 . 
 ead space. 
 281 ppm e opening 

ppm of Carbon.~isulftde 

. - ~. . . . .

* See Table VI for more detailed sample description and additional short-term samples for carbon 


disulfide. BZ denotes breathing zone sample. . 
 ** Concentrations are .given in parts per million (ppm) and breakthrough of the sample (i.e., loss from overloading) is designated with a+; ND denotes .sample was below the limit~ of detection. 

( ..· 

,· \ 

!

, 

... 

•.., rl 11 r 1 
H 

Carbon Tetrachloride Fumigant Levels Obtained From Rail Car Grain Shipments 
 Portland Field Office Inspection Sftes 


Portland. Oregon HETA 83-375 

ppm of Carbon of Carbon Tetrachloride 

· car Number and 

Sample Descrfptfon* 

LQO ··= ~-00 ·~00 1

400 

I so,o £;§0 7@.0 ago 'J0.fJ 14,W noo

9 

Above grain fn car I 0 .14 ppm 

In-mass, tn car 1· I 278 ppm 

OZ of grain inspector ND** 


during fnspectf~n 


UP 73735 i 0 . 91 ppm Above grain. fn car :1, 

,. !ft-mass, tn car I I 249 ppm+** f.; 

BZ of grain inspector : rm 


during fnspectfon 


UP 22293 L__J 37 ppm Car head space.
 before opening 


ppm Above grain. fn car ~ 0 .21 

In-mass. fn car . l 199 ppm 

BZ ~f grain 1nspector ,t NO 


during inspection 


UP 14546 I I 64 ppm Car head space,
 . '

before opening 


Above grafn. fn car I 424 ppm+ 


In-mass in car . 
 f 244 ppm

., .. 

i , , 

.--~ ) 

I ... Continued ·. .. ' l 

. :.•: ~ 

t-1gure 
BZ of Grain inspector. L 

~uring inspection ND 

UP 76314 184 ppm+
 Car head space. 


before opening 


Above grain in car 1.4 ppm

In.,.mass. in car L_:.____________________ 689 ppm+ 

ez of grain inspector. during inspection LND 

BN 452278 

Car head space 455 ppm+ before opening 

!.. UTCX 44256 

Car head space. 

before opening .goo 

*See .Table VI for .more detailed sample description and additional short-term samples for carbon 


tetrachloride. BZ denotes breathing zone sample. 


**Concentrations are given 1n · parts per mil lion (ppm) and break through (1.e., loss from overloading) 1s 

designated with a_+; ND denotes sample was below the limits of detection. 

r--;-­

.. ., 

# • · ; a 

I ...,.. · -· ·•f ... 
Appendix A 


Analytical Methods and Modifications 


Federal Grain Inspection Service 


Portland, Oregon 


HETA 83-375 


Ethylene Dibromide: Analytical Method 

The following conditions were used on the gas chromatograph {GC) eauipped with 

an electron capture detector {ECO) for the initial survey sample set: 

Instrument: Hewlett Packard 5840 with ECO 

Column: 3% OV-17 on WHP {6 ft x 1/8 inch OD 

glass column)

Carrier Gas: 95t argon/Si methane - 28 ml/min

Colum·n Temperature: 75°C isothermal (4 min) 

Injector Temperature: 2so 0

c 

Detector Temperature: 300°C 

Injection VoJurre: 1 UL 

Attenuation: 2 8 

The front sections of the charcoal tubes were desorbed for at least 1 hour 

with 10 ml of lt methanol in benzene. The back sections were desorbed in 1 ml 

of this solution. Tetrachlor~ethane was added as an internal standard at 200 

ng/mL. 

For the follow-up survey sample set these GC/ECD conditions were used for 

ethylene dibromide: 

Instrument: Varian Vista 6000 CC with ECO 

Column: DB-5 fused silica capillary 

column, 30 M x 0.32 mm ID 

Carrier Gas: 2 ml/min Helium 

Make-up Gas: . 28 ml/min Nitrogen 

Column Temperature: 40°C 

Injector Temperature: 200°c 

Detector Temperature: 285°C 

Injection Volume: 1 ul 

Range: · 1 

Attenuation: 16 

Chart Speed: 1.0 cm/min : 

The charcoal tubes were desorbed in the sarre manner as the previous set. No 

internal standard is indicated. 

(Continued) 

·-, 


I 
Appendix A 

(Continued} 

Carbon Disulfide: Modifications to NIOSH Method S-248 

Desorption Process: 
 1 hour in 1 ml benzene 

Gas Chromatograph: 
 Tracor Model MT-220 equipped with a 

flame photometric detector, operated 

in the sulfur mode 

Column : 3' x 2 ltl!1. ID glass column packed wi~h 

3i OV-17 and 3i OF-1 on 100/120 mesh 

chromosorb G 

Oven Conditions: 
 50°C isothermal 

Other: 
 Nitrogen was used as the carrier gas 

The following conditions were changed for the analysis of the follow-up survey 

carbon disulfide sample set: 

Column: 28" x 1/4" glass packed with 2: 

OV-225 on 80/100 Supelcoport. Oven Conditions: 70 °~ Isotherma1 

Carbon Tetrachloride, Chloroform, 1,2-Dichloroethane, 1,2-0ichloroethylene: Modification to NIOSH Method P&CAM 127 . 

Desorption Process: 30 mi.nutes in 1.0 milliliter of carbon 

disulfide containing 1 microliter/ 

milliliter of benzene as an internal 

standard 

Gas Chromatograph: Hewlett-Packard Model 5711A equipped 

with a flame ionization detector 

Column:. 60 m x 0.32 mm ID fused silica capillary 

coated internally with 0.25 um of 

OV-351 · Oven Conditions: Temperature programming from 55°C 


(held for 8 min) to 100°c at a 


rate of 8°C/minute 


The following modifications were made in NIOSH Method S-314 during analysis of 

the follow-up survey carbon tetrachloride sample set: 

Desorption Process: 30 minutes in 1.0 milliliter of carbon 

disulfide containing 1 m1croliter per 

milliliter of toluene as an ·;nternal 

standard 

(Continued) 

..... 

' 
Appendix A 

(Continued) 

Column: 
 20' x 1/8" OP stainless steel packed with 

20i SP 2100, O.lt CW 1500 on 100/120 

Supelcoport Oven Conditions: 
 120°c isothermal 

Methyl Bromide: Analytical Method 

The following GC/ECO condit·ions were used in the methyl bromide analysis: 

Instrurrent: Hewlett Packard 5840 GC with ECD 

Column: 1i SP-1000 on 60/80 Carbopack B 

(6 ft x 2 nun ID glass column) 

Carrier Gas: 5% Methane/95% Argon at 30mL/min 

Column Temperature: 45°C isothermal (30 min) 

Injector Temperature: 200°c 

Detector Temperature: 250°C 

Injection Volurr~: · 1 UL 

Attenuation: 24 

Retention Time: 3.70 min 

The front sections of the charcoal tubes were desorbed for at least 1 hour with 2 

ml o.f a methanol in benzene. 

.r~ i 

, l ··,7. 

.. •. .:,- ...· 
Short-Terr.. Air Bag Sampling: Carbon Tetrachloride and Carbon Disulfide 

Air· samples were collected in aluminized mylar bags above and within the grain 

mass of two treated grain shipments and at various locations throughout the 

elevator as this grain was transferred to storage bins. The bags were filled 

using an SKC Universal Pump equipped with a bag filling port and an inlet 

probe of Tygon tubing fitted with a particulate ·filter on the probe end. 

In-the-mass samples are for a single location in the grain . The amount of 

time required to fill the bags was about five minutes. 

Samples were taken to the field lab where they were analyzed for carbon 

tetrachloride and carbon disulfide. These two compounds appear to be the 

primary ·constituents of a corrmonly used grain fumigant generally referred to 

as . "80-20" (BOX carbon tetfachloride, 2oi carbon disulfide). All bags were 

letter -coded and all bags were flushed with clean (room) air and analyzed for 

residual fumigant levels prior to reuse. Samples were usually analyzed within 

a short time after collection, normally less than one hour. 

Sample·s were injected into a gas chromatograph using a microliter gas 

syringe. Analyses were all run a minimum ·of two times for each sample. The 

Pho·tovac Model lOAlO gas chromatograph (Photovac, Inc., Thornhi 11, Ontario, 

Canada L3T 1L·3) was equipped with a photoionization detector and was operated 

under the following conditions: 

Temperature: 68-74°F (ambient) 


Carrier Gas: Air at 30 psig and 30 cc/minute 


Column: CSP 20, 41 x 1/8", 80-100 mesh 


The output was to a strip chart recorder, (Linear Model 142) operated at 100 

millivolts full scale and a chart speed of 0.5 cm/minute. The gas .. chromatograph was operated on an attenuation of 20 or 50 and the injected 

sample volume ranged from 50 to 400 microliters depending upcn fumigant 

concentration. 

Standards were prepared from liquid reagents (carbon disulfide, carbon 

tetrachloride, and ethylene dibromide) by adding microliter quantities to 

metered volumes o_f air in aluminized reylar bags. 
Carbon Disulfide, Carbon Tetrachlor_ide Short-Term Sorbent Samples: 

Modification to NIOSH Method S-248 

The samples were desorbed for a minimum of 30 minute.sin 1.0 milliliter 

benzene. . 

The analysis of carbon disulfide was performed on a.Tracor 220 gas 

chromatograph equipped with a flame ·photometric detector in the sulfur mode. 

A 28" x 1/4" glass column packed with 2t OV-225 on 80/100 Suplecoport was used .._.. r 

at an isothermal temperature of 70°C. · 

The analysis of carbon tetrachloride was performed on a Hewlett Packard Model 

5711A gas chromatograph equipped with a flame ionization detector~ A 12' x 

l/811 stainless steel column packed with 10% _TCEP on 80/100 mesh chromosorb ·PAW 

was used at an oven temperature of 100°c. 

Carbon Disulfide and Carbon Tetrachloride Confirmation 

Samples previously prepared for analysis by desorption in benzene, analyzed 

and found to contain both CS2 and CCl4 by standard chromatographic methods 

were reanalyzed on a Hewlett Packard 5992 gas chromatograph/mass spectrometer 

to confirm the presence of CS2 and CCl4. A 30 m wi~e-bore fused silica 

capillary column was used isothermally at 22°c with a split injection ratio of 

20:1. 

-..; 

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