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Immediately Dangerous to Life or Health (IDLH) Value Profile

Ethylene Dibromide

[CAS® No. 106-93-4]

DEPARTMENT OF HEALTH AND HUMAN SERVICEs

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health 

 

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health
ii IDLH Value Profile for Ethylene Dibromide 

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Suggested Citation

NIOSH [2020]. Immediately dangerous to life or health (IDLH) value profile: ethylene dibromide, CAS® No. 106-93-4. By Niemeier RT. Cincinnati, OH: U.S. Department of Health 

and Human Services, Centers for Disease Control and Prevention, National Institute for 

Occupational Safety and Health, DHHS (NIOSH) Publication 2020-125.

DOI: https://doi.org/10.26616/NIOSHPUB2020125

DHHS (NIOSH) Publication No. 2020-125

July 2020
IDLH Value Profile for Ethylene Dibromide iii

Foreword

Chemicals are a ubiquitous component of the modern workplace. Occupational exposures 

to chemicals have the potential to adversely affect the health and lives of workers. Acute or 

short-term exposures to high concentrations of some airborne chemicals can quickly overwhelm workers, resulting in a spectrum of undesirable health outcomes that may inhibit the 

ability to escape from the exposure environment (e.g., irritation of the eyes and respiratory 

tract or cognitive impairment), cause severe irreversible effects (e.g., damage to the respiratory tract or reproductive toxicity), and in extreme cases, cause death. Airborne concentrations of chemicals capable of causing such adverse health effects or of impeding escape from 

high-risk conditions may arise from a variety of non-routine workplace situations, including 

special work procedures (e.g., in confined spaces), industrial accidents (e.g., chemical spills or 

explosions), and chemical releases into the community (e.g., during transportation incidents 

or other uncontrolled-release scenarios). 

The immediately dangerous to life or health (IDLH) air concentration values developed by 

the National Institute for Occupational Safety and Health (NIOSH) characterize these highrisk exposure concentrations and conditions [NIOSH 2013]. IDLH values are based on a 

30-minute exposure duration and have traditionally served as a key component of the decision logic for the selection of respiratory protection devices [NIOSH 2004]. 

Occupational health professionals have employed these values beyond their initial purpose 

as a component of the NIOSH Respirator Selection Logic to assist in developing risk management plans for non-routine work practices governing operations in high-risk environments 

(e.g., confined spaces) and the development of emergency preparedness plans. 

The approach used to derive IDLH values for high-priority chemicals is outlined in the 

NIOSH Current Intelligence Bulletin (CIB) 66: Derivation of Immediately Dangerous to Life 

or Health (IDLH) Values [NIOSH 2013]. CIB 66 provides (1) an update on the scientific 

basis and risk assessment methodology used to derive IDLH values, (2) the rationale and 

derivation process for IDLH values, and (3) a demonstration of the derivation of scientifically 

credible IDLH values, using available data resources.

This technical report presents the IDLH value for Ethylene Dibromide (CAS® No. 106-93-4). 

The scientific basis, toxicologic data, and risk assessment approach used to derive the IDLH 

value are summarized to ensure transparency and scientific credibility. 

John Howard, M.D.

Director

National Institute for Occupational Safety

 and Health

Centers for Disease Control and Prevention 
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IDLH Value Profile for Ethylene Dibromide v

Contents

Foreword ...................................................... iii

Abbreviations ................................................... vi

Glossary ....................................................... viii

Acknowledgments ............................................... xii

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

1.1 Overview of the IDLH Value for Ethylene Dibromide ................ 1

1.2 Purpose ................................................... 1

1.3 Literature Search Strategy and Data Evaluation ..................... 1

1.4 General Substance Information ................................. 1

2 Human Data .................................................. 4

3 Animal Toxicity Data ........................................... 4

4 Summary ..................................................... 10

5 References .................................................... 11

Appendix A. Literature Search Strategy and Data Evaluation ............... 14
vi IDLH Value Profile for Ethylene Dibromide 

Abbreviations

ACGIH® American Conference of Governmental Industrial Hygienists 

AEGLs Acute Exposure Guideline Levels

AIHA® American Industrial Hygiene Association 

BMC benchmark concentration 

BMD benchmark dose

BMCL benchmark concentration lower confidence limit 

BMR benchmark response 

C ceiling value

°C degrees Celsius

Ca carcinogen

CAS® Chemical Abstracts Service, a division of the American Chemical Society

CIB Current Intelligence Bulletin

ECt50 median effect vapor concentration

ERPGsTM Emergency Response Planning Guidelines 

°F degrees Fahrenheit

g grams

IDLH immediately dangerous to life or health

IFA Institut für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung

 (Institute for Occupational Safety and Health of the German Social

 Accident Insurance)

L liter

LC lethal concentration

LC50 median lethal concentration

LCt50 median lethal time

LCLO lowest concentration that caused death in humans or animals

LD50 lethal dose

 LDLO lowest dose that caused death in humans or animals

LEL lower explosive limit

LOAEL lowest observed adverse effect level 

mg milligrams

mg/m3

 milligram(s) per cubic meter

min minutes

mL milliliters

mmHg millimeter(s) of mercury

NAS National Academy of Sciences

NIOSH National Institute for Occupational Safety and Health

NLM National Library of Medicine

NOAEL no observed adverse effect level 
IDLH Value Profile for Ethylene Dibromide vii

NRC National Research Council

NTP National Toxicology Program

OSHA Occupational Safety and Health Administration

PBPK physiologically based pharmacokinetic

PEL permissible exposure limit 

POD point of departure

ppm parts per million 

RD50 concentration of a chemical in the air that is estimated to cause a 50%

decrease in the respiratory rate

REL recommended exposure limit 

STEL short-term exposure limit 

TLV® Threshold Limit Value 

TWA time-weighted average 

UEL upper explosive limit

UF uncertainty factor

WEELs® Workplace Environmental Exposure Levels
viii IDLH Value Profile for Ethylene Dibromide 

Glossary

Acute exposure: Exposure by the oral, dermal, or inhalation route for 24 hours or less. 

Acute Exposure Guideline Levels (AEGLs): Threshold exposure limits for the general public, 

applicable to emergency exposure periods ranging from 10 minutes to 8 hours. AEGL-1, 

AEGL 2, and AEGL-3 are developed for five exposure periods (10 and 30 minutes, 1 hour, 

4 hours, and 8 hours) and are distinguished by varying degrees of severity of toxic effects, 

ranging from transient, reversible effects to life-threatening effects [NRC 2001]. AEGLs are 

intended to be guideline levels used during rare events or single once-in-a lifetime exposures 

to airborne concentrations of acutely toxic, high-priority chemicals [NRC 2001]. The threshold exposure limits are designed to protect the general population, including the elderly, 

children, and other potentially sensitive groups that are generally not considered in the development of workplace exposure recommendations (additional information available at https://

www.epa.gov/oppt/aegl/). 

Acute reference concentration (Acute RfC): An estimate (with uncertainty spanning perhaps 

an order of magnitude) of a continuous inhalation exposure for an acute duration (24 hours 

or less) of the human population (including sensitive subgroups) that is likely to be without 

an appreciable risk of deleterious effects during a lifetime. It can be derived from a NOAEL, 

LOAEL, or benchmark concentration, with uncertainty factors (UFs) generally applied to 

reflect limitations of the data used. Generally used in U.S. EPA noncancer health assessments 

[EPA 2019]. 

Acute toxicity: Any poisonous effect produced within a short period of time following an exposure, usually 24 to 96 hours [EPA 2019]. 

Adverse effect: A substance-related biochemical change, functional impairment, or pathologic lesion that affects the performance of an organ or system or alters the ability to respond to 

additional environmental challenges. 

Benchmark dose/concentration (BMD/BMC): A dose or concentration that produces a predetermined change in response rate of an effect (called the benchmark response, or BMR) 

compared with background [EPA 2019] (additional information available at https://www.epa.

gov/ncea/bmds/). 

Benchmark response (BMR): An adverse effect, used to define a benchmark dose from which 

a reference dose or concentration can be developed. The change in response rate over background of the BMR is usually in the range of 5% to 10%, which is the limit of responses typically observed in well-conducted animal experiments [EPA 2019]. 

Benchmark concentration lower confidence limit (BMCL): A statistical lower confidence limit 

on the concentration at the BMC [EPA 2019]. 

Bolus exposure: A single, relatively large dose. 

Ceiling value (“C”): Term in occupational exposure indicating the airborne concentration of a 

potentially toxic substance that should never be exceeded in a worker’s breathing zone. 
IDLH Value Profile for Ethylene Dibromide ix

Chronic exposure: Repeated exposure for an extended period of time. Typically, exposures 

are more than approximately 10% of life span for humans and >90 days to 2 years for laboratory species. 

Critical study: The study that contributes most significantly to the qualitative and quantitative 

assessment of risk [EPA 2019].

Dose: The amount of a substance available for interactions with metabolic processes or biologically significant receptors after crossing the outer boundary of an organism [EPA 2019]. 

ECt50: A combination of the effective concentration of a substance in the air and the exposure 

duration that is predicted to cause an effect in 50% of the experimental test subjects. 

Emergency Response Planning Guidelines (ERPGsTM): Maximum airborne concentrations 

below which nearly all individuals can be exposed without experiencing health effects for 

1-hour exposure. ERPGs are presented in a tiered fashion, with health effects ranging from 

mild or transient to serious, irreversible, or life threatening (depending on the tier). ERPGs 

are developed by the American Industrial Hygiene Association [AIHA 2016]. 

Endpoint: An observable or measurable biological event or sign of toxicity, ranging from biomarkers of initial response to gross manifestations of clinical toxicity. 

Exposure: Contact made between a chemical, physical, or biological agent and the outer 

boundary of an organism. Exposure is quantified as the amount of an agent available at the 

exchange boundaries of the organism (e.g., skin, lungs, gut). 

Extrapolation: An estimate of the response at a point outside the range of the experimental 

data, generally through the use of a mathematical model, although qualitative extrapolation 

may also be conducted. The model may then be used to extrapolate to response levels that 

cannot be directly observed. 

Hazard: A potential source of harm. Hazard is distinguished from risk, which is the probability of harm under specific exposure conditions. 

Immediately dangerous to life or health (IDLH) condition: A condition that poses a threat of 

exposure to airborne contaminants when that exposure is likely to cause death or immediate 

or delayed permanent adverse health effects or prevent escape from such an environment 

[NIOSH 2004, 2013]. 

IDLH value: A maximum (airborne concentration) level above which only a highly reliable 

breathing apparatus providing maximum worker protection is permitted [NIOSH 2004, 

2013]. IDLH values are based on a 30-minute exposure duration. 

LC01: The statistically determined concentration of a substance in the air that is estimated to 

cause death in 1% of the test animals. 

LC50: The statistically determined concentration of a substance in the air that is estimated to 

cause death in 50% of the test animals; median lethal concentration. 

LCLO: The lowest lethal concentration of a substance in the air reported to cause death, usually 

for a small percentage of the test animals.
x IDLH Value Profile for Ethylene Dibromide 

LD50: The statistically determined lethal dose of a substance that is estimated to cause death 

in 50% of the test animals; median lethal concentration. 

LDLO: The lowest dose of a substance that causes death, usually for a small percentage of the 

test animals. 

Lethality: Pertaining to or causing death; fatal; referring to the deaths resulting from acute 

toxicity studies. May also be used in lethality threshold to describe the point of sufficient 

substance concentration to begin to cause death. 

LEL: The minimum concentration of a gas or vapor in air, below which propagation of a flame 

does not occur in the presence of an ignition source. 

Lowest observed adverse effect level (LOAEL): The lowest tested dose or concentration of a 

substance that has been reported to cause harmful (adverse) health effects in people or animals.

Mode of action: The sequence of significant events and processes that describes how a substance causes a toxic outcome. By contrast, the term mechanism of action implies a more 

detailed understanding on a molecular level. 

No observed adverse effect level (NOAEL): The highest tested dose or concentration of a substance that has been reported to cause no harmful (adverse) health effects in people or animals.

Occupational exposure limit (OEL): Workplace exposure recommendations developed by governmental agencies and nongovernmental organizations. OELs are intended to represent the 

maximum airborne concentrations of a chemical substance below which workplace exposures 

should not cause adverse health effects. OELs may apply to ceiling limits, STELs, or TWA 

limits. 

Peak concentration: Highest concentration of a substance recorded during a certain period 

of observation. 

Permissible exposure limits (PELs): Occupational exposure limits developed by OSHA (29 

CFR 1910.1000) or MSHA (30 CFR 57.5001) for allowable occupational airborne exposure 

concentrations. PELs are legally enforceable and may be designated as ceiling limits, STELs, 

or TWA limits.

Point of departure (POD): The point on the dose-response curve from which dose extrapolation is initiated. This point can be the lower bound on dose for an estimated incidence or a 

change in response level from a concentration-response model (BMC), or it can be a NOAEL 

or LOAEL for an observed effect selected from a dose evaluated in a health effects or toxicology study. 

RD50: The statistically determined concentration of a substance in the air that is estimated to 

cause a 50% decrease in the respiratory rate. 

Recommended exposure limit (REL): Recommended maximum exposure limit to prevent 

adverse health effects, based on human and animal studies and established for occupational 

(up to 10-hour shift, 40-hour week) inhalation exposure by NIOSH. RELs may be designated 

as ceiling limits, STELs, or TWA limits. 
IDLH Value Profile for Ethylene Dibromide xi

Short-term exposure limit (STEL): A worker’s 15-minute time-weighted average exposure concentration that shall not be exceeded at any time during a work day. 

Target organ: Organ in which the toxic injury manifests in terms of dysfunction or overt 

disease. 

Threshold Limit Values (TLVs®): Recommended guidelines for occupational exposure to airborne contaminants, published by the American Conference of Governmental Industrial 

Hygienists (ACGIH®). TLVs refer to airborne concentrations of chemical substances and 

represent conditions under which it is believed that nearly all workers may be repeatedly 

exposed, day after day, over a working lifetime, without adverse effects. TLVs may be designated as ceiling limits, STELs, or 8-hour TWA limits. 

Time-weighted average (TWA): A worker’s 8-hour (or up to 10-hour) time-weighted average 

exposure concentration that shall not be exceeded during an 8-hour (or up to 10-hour) work 

shift of a 40-hour week. The average concentration is weighted to take into account the duration of different exposure concentrations. 

Toxicity: The degree to which a substance can cause an adverse effect on an exposed organism.

Uncertainty factors (UFs): Mathematical adjustments applied to the POD when developing 

IDLH values. The UFs for IDLH value derivation are determined by considering the study 

and effect used for the POD, with further modification based on the overall database. 

Workplace Environmental Exposure Levels (WEELs®): Exposure levels developed by the 

American Industrial Hygiene Association (AIHA®) that provide guidance for protecting most 

workers from adverse health effects related to occupational chemical exposures, expressed 

as TWA or ceiling limits. 
xii IDLH Value Profile for Ethylene Dibromide 

Acknowledgments

This document was developed by the Division of Science Integration, Paul Schulte, Ph.D., Director. R. Todd Niemeier, MS, CIH, was the project officer and lead NIOSH author. The basis for 

this document was a report (Toxicology Excellence for Risk Assessment [TERA]) contracted by 

NIOSH and prepared by Andrew Maier, Ph.D., Ann Parker, and Lynn Haber, Ph.D. 

The following NIOSH staff are acknowledged for providing technical and editorial review of the 

report:

Division of Science Integration 

Devin Baker, M.Ed. 

G. Scott Dotson, Ph.D. (formerly with NIOSH)

Sherry Fendinger, M.L.I.S.

Charles L. Geraci, Ph.D. 

Thomas J. Lentz, Ph.D. 

Richard W. Niemeier, Ph.D. (retired)

Pranav Rane, M.P.H.

Chris Whittaker, Ph.D.

NIOSH acknowledges the following subject matter experts for their critical technical reviews: 

Michael S. Bisesi, Ph.D., R.E.H.S., C.I.H., senior associate dean for academic affairs; Director, 

Center for Public Health Practice; interim chair and associate professor, Division of Environmental Health Science, College of Public Health, Ohio State University, Columbus, OH

Iris Camacho, Ph.D., branch chief, Assessment Branch 1, Risk Assessment Division, Office 

of Pollution Prevention and Toxics, U.S. Environmental Protection Agency, Washington, DC

Mary A. Fox, Ph.D., assistant professor; co-director, Risk Sciences and Public Policy Institute; Department of Health Policy and Management, Bloomberg School of Public Health, 

Johns Hopkins University, Baltimore, MD

Matthew Lloyd, CIH, New Chemicals Management Branch, Chemical Control Division, 

Office of Pollution Prevention and Toxics, U.S. Environmental Protection Agency, Washington, DC

Bill Luttrell, Ph.D., chair and professor, Department of Chemistry and Physics, College of 

Natural and Health Sciences, Oklahoma Christian University, Edmond, OK

Laurie Roszell, Ph.D., toxicologist, Army Center for Public Health, Environmental Health 

Risk Assessment Division, Aberdeen Proving Ground, MD

George M. Woodall, Ph.D., toxicologist, National Center for Environmental Assessment, 

Office of Research and Development, U.S. Environmental Protection Agency, Research 

Triangle Park, NC
IDLH Value Profile for Ethylene Dibromide 1

1 Introduction 

1.1 Overview of the IDLH 

Value for Ethylene 

Dibromide

IDLH Value: 46 ppm (354 mg/m3)

Basis for IDLH Value: The immediately dangerous to life or health (IDLH) value for ethylene 

dibromide is based on a 36-minute no observed 

adverse effect level (NOAEL) for lethality value of 400 ppm in rats [Rowe et al. 1952]. The 

duration-adjusted value for a 30-minute exposure is 456 ppm. An uncertainty factor (UF) 

of 10 was applied (1 to account for interspecies 

variability [animal to human] and 10 to account 

for human variability). This resulted in a point 

of departure (POD) of 456 ppm, divided by a 

UF of 10 or an IDLH of 46 ppm.

1.2 Purpose

This IDLH Value Profile presents a brief summary of technical data associated with acute 

inhalation exposures to ethylene dibromide 

and the rationale behind the IDLH value for 

ethylene dibromide. IDLH values are developed on the basis of scientific rationale and 

logic outlined in the NIOSH Current Intelligence Bulletin (CIB) 66: Derivation of Immediately Dangerous to Life or Health (IDLH) 

Values [NIOSH 2013]. 

1.3 Literature Search 

Strategy and Data 

Evaluation

As described in CIB 66, NIOSH performed 

in-depth literature searches to ensure that all 

relevant data from human and animal studies 

with acute exposures to the substance were 

identified. See Appendix A for further information about the literature search strategy 

and data evaluation methods.

1.4 General Substance 

Information 

Chemical: Ethylene dibromide

CAS No: 106-93-4

Synonyms*†: 1,2-Dibromoethane; 

dibromoethane; EDB

Chemical category†: Aliphatic, saturated 

halogenated hydrocarbons; Organic bromine 

compounds

Structural formula‡:

 

References: *EPA [2008],†IFA [2019];‡NLM [2019] 
2 IDLH Value Profile for Ethylene Dibromide 

Table 1 highlights selected physiochemical 

properties of ethylene dibromide relevant to 

IDLH conditions. Table 2 provides a summary of existing exposure guidelines for ethylene 

dibromide. Table 3 summarizes the Acute 

Exposure Guideline Level (AEGL) values for 

ethylene dibromide.

Table 1. Physiochemical Properties of Ethylene Dibromide*

Property Value

Molecular weight 187.9†

Chemical formula BrCH2CH2Br*

Description Colorless liquid or solid (below 50°F) with a sweet odor 

[fumigant]†

Odor Sweet odor†

Odor threshold Low: 76.9 mg/m3 (10 ppm)*

UEL Not applicable (noncombustible liquid)†

LEL Not applicable (noncombustible liquid)†

Vapor pressure 11 mmHg@25°C (77°F)†; 17.4 mmHG@30°C (86°F)*

Flash point Not applicable (noncombustible liquid)†

Ignition temperature Not applicable (noncombustible liquid)†

Solubility 0.43 g/100 ml water; soluble in ethanol and ethyl ether; 

miscible with most solvents and thinners*

*EPA [2008]; †NIOSH [2019]

Table 2. Alternative Exposure Values for Ethylene Dibromide

Organization Value

Revised (1994) IDLH value* 100 ppm

NIOSH REL† 0.045 ppm, TWA [Ca]; 0.13 ppm, 15-minute ceiling 

OSHA PEL‡ 20 ppm, TWA; 30 ppm, ceiling; 50 ppm, 5-minute maximum 

peak during an 8-hour shift

ACGIH® TLV§ Skin; A3 (Not classifiable as human carcinogen)

AIHA® ERPGsTM¶ Not available

AIHA® WEELs® ** Not available

References: *NIOSH [1994]; †NIOSH [2019]; ‡OSHA [2019]; §ACGIH [2019]; ¶AIHA [2016]; **TERA [2014]
IDLH Value Profile for Ethylene Dibromide 3

Table 3. Interim AEGL Values for Ethylene Dibromide*

Classification 10-min 30-min 1-hour 4-hour 8-hour Endpoint/ Reference

AEGL-1(Nondisabling)

52 ppm400 mg/m3

26 ppm200 mg/m3

17 ppm 131 mg/m3

7.1 ppm55 mg/m3

4.6 ppm35 mg/m3

NOAEL for liver toxicity [Rowe 1952]

AEGL-2(Disabling)

73 ppm562 mg/m3

37 ppm285 mg/m3

24 ppm185 mg/m3

10 ppm77 mg/m3

6.5 ppm50 mg/m3

Slight histopathological changes in the liver; no effect-level for irreversible toxicity [Rowe 1952]

AEGL-3(Lethal)

170 ppm1,308 mg/m3

76 ppm585 mg/m3

46 ppm354 mg/m3

17 ppm131 mg/m3

10 ppm77 mg/m3

No effect level for lethality [Rowe 1952]

*Reference: EPA [2008]
4 IDLH Value Profile for Ethylene Dibromide 

2 Human Data

There were two limited reports available regarding human lethality from exposure to 

ethylene dibromide. Letz et al. [1984] reported death from acute liver and renal failure in 

two workers exposed via inhalation and dermal contact while working in a tank used to 

store fertilizer mixtures containing 0.1% to 

0.3% ethylene dibromide. Air samples collected 20 hours after the incident contained 

15 to 41 ppm (average = 28 ppm) in air. The 

first worker was exposed for approximately 

45 minutes and the second worker was exposed for 20 to 30 minutes, while attempting 

to rescue the first worker. The first worker 

collapsed within the first 5 minutes of exposure. Other effects included vomiting, eye 

and respiratory irritation, central nervous system effects, and diarrhea, resulting in an intermittent comatose state.

Ott et al. [1980] reported that a strong odor 

and respiratory irritation occur when ethylene dibromide concentrations reach 75 

ppm, and that gastrointestinal discomfort 

and vomiting may also occur during acute exposure. No other details were reported.

A few studies have evaluated the potential 

effects of ethylene dibromide on male fertility following occupational exposure [Wong et 

al. 1979a; Ratcliffe et al. 1987; Schrader et al. 

1987, 1988]. Though all three of these studies suggested reproductive effects following 

exposure to ethylene dibromide, it is unclear 

whether these effects would occur as a result 

of an acute exposure. In addition, these study 

reports noted confounding factors that may 

have contributed to the reproductive effects 

observed, including tobacco and substance 

use, age, ethnicity, and history of urogenital 

disorders and other illnesses [Ratcliffe et al. 

1987; Schrader et al. 1987, 1988]. These data 

were not adequate for the derivation of an 

IDLH value.

The weight of evidence suggests that irritative 

and toxic effects occur with human exposure 

to ethylene dibromide; however, quantitative 

data to determine a POD for derivation of an 

IDLH value on human data were not identified. 

3 Animal Toxicity Data 

Lethality studies on ethylene dibromide are 

limited. In a dog study [Merzbach 1929], one 

dog for each concentration was exposed to 1, 

2, or 5 mL of vaporized ethylene dibromide 

in a 100-L bell jar for 1 hour. These values are 

equivalent to 30-minute adjusted exposure 

concentrations of 4,697 ppm, 9,396 ppm, and 

23,485 ppm. All exposed dogs died, although 

the one exposed to the lowest concentration 

died 3 weeks post-exposure. Effects seen 

at the lowest concentration included signs 

of restlessness, eye irritation, labored respiration, and increased respiration rate during 

exposure. More severe effects, such as lung, 

heart, and liver damage, occurred at higher 

concentrations. No information was provided 

on whether or not control animals were included in this study.

In the only available acute study conducted 

according to modern methods, Rowe et al. 

[1952] exposed groups of four to 30 rats to 

100, 200, 400, 800, 1,000, 3,000, 5,000, or 

10,000 ppm of ethylene dibromide vapor. Exposure durations ranged from 1.2 minutes to 

16 hours. Rat deaths varied over the concentrations and duration tested. NOAELs for lethality are presented in Table 4. The 30-minute adjusted concentration values ranged from 

456 to 1,189 ppm. Additionally, on the basis 
IDLH Value Profile for Ethylene Dibromide 5

of the duration response at each concentration, NIOSH [1977] calculated LC50 values 

at each concentration. These values can also 

be interpreted as the LC50 at each respective 

lethal time and are presented in Table 5. The 

30-minute adjusted concentrations for the 

LC50 values ranged from 1,069 to 1,642 ppm. 

Deaths at the high concentrations were attributed to cardiac and respiratory failure. 

Deaths seen in groups with <50% mortality 

occurred several days post-exposure and were 

caused by pneumonia secondary to pulmonary damage. Prior to death, effects included 

weight loss, rough and unkempt appearance, 

irritability, and bloody discharge from the 

nose. Increased liver weight and slight histopathologic changes in the liver (not further 

described) were estimated to be associated 

with the following concentration/time combinations: 800 ppm for 9 minutes, 200 ppm 

for 1 hour, and 100 ppm for 4 hours. These 

liver effects were not considered escape-impairing or severe, and they appeared to be reversible, although there is some uncertainty 

in the absence of additional description of 

the effects. However, as noted in the next 

paragraph, there were no liver lesions at 75 

ppm in a subchronic study [NTP 1982]. In 

a repeated-exposure study, Nitschke et al. 

[1981] reported signs of nose and eye irritation during the first 6-hour exposure to 40 

ppm, but the severity of these effects was 

not described. Irritation was not observed at 

lower concentrations or after repeated exposures. Another study in rats determined that 

the LC50 of ethylene dibromide was 1,862 

ppm, and 100% mortality occurred at 2,902 

ppm with 30-minute exposures [Bakhishev 

1973]. No details on the experimental design 

were provided in the Russian-translated publication.

Another study exposed rats (n = 12) to ethylene dibromide vapors at 1,660 ppm for 1, 

3, and 6 hours [Koptagel and Bulut 1998]. 

Tracheal tissues were harvested at the end 

of the exposure period, and tissue damage 

was semi-quantitatively scored. At 1 hour of 

exposure, mild lymphocyte infiltration and 

hyperemia were reported, as were moderate vascular dilation and lumen hemorrhage. 

All of these effects were reported as mild to 

severe in the 3-hour and 6-hour exposure 

groups. No epithelial damage was noted at 1 

hour of exposure, but moderate damage was 

reported at 3 and 6 hours of exposure.

Another study exposed white rats to 1,000 

ppm of ethylene dibromide [Akamine 1952]. 

Results were reported as the time required 

to kill animals, based on weight (190–604 

grams), but the number of animals in each 

weight group was not provided. The time 

for lethality ranged from 60 to 105 minutes. 

Visible signs of ethylene dibromide poisoning 

were reported, including nasal bleeding and 

mucous membrane reddening, weight and 

appetite loss, and excessive salivation. 

Groups of guinea pigs were also exposed to 

ethylene dibromide, including 20 animals exposed to vapors at 400 ppm for 7 hours, 5 

hours, or 2 hours; 10 animals exposed to 400 

ppm for 3 hours; and 15 animals exposed to 

200 ppm for 7 hours [Rowe et al. 1952]. Of 

the animals exposed to 400 ppm, 20/20 died 

in the 7-hour exposure group, 18/20 died in 

the 5-hour exposure group, and 5/10 died in 

the 3-hour exposure group. No animals died 

at the 400-ppm exposure for 2 hours or 200-

ppm exposure for 7 hours. Descriptions of 

clinical signs or necropsy results were not 

provided [Rowe et al. 1952]. 

Rowe et al. [1952] also exposed two monkeys to 50 ppm of ethylene dibromide for 

70 days (7 hours/day, 5 days/week). Animals 

appeared ill, unkempt, and nervous and lost 

5% of body weight over the course of the experiment. At the end of the experiment, it 

was determined that the animals had “very 

slight” central fatty degeneration and increased lipid values in the liver, as well as a 

slight increase in kidney weights. No other 

significant effects were noted. In a similar 

study, two monkeys were exposed to 25 ppm 
6 IDLH Value Profile for Ethylene Dibromide 

of ethylene dibromide for 156 exposure periods in 220 days (no other exposure details 

were provided) [Rowe et al. 1952]. No adverse effects from these exposures were 

reported by the authors. 

Table 5 summarizes the LC data identified 

in animal studies and provides 30-minuteequivalent derived values for ethylene dibromide. Information in this table includes species of test animals, LC50 values, and the adjusted 30-minute concentrations.

Nasal lesions were reported to occur in rats 

and mice exposed subchronically (6 hours/

day, 5 days/week, for up to 13 weeks) to 

non-lethal concentrations of ethylene dibromide in two studies, at concentrations of 10 

ppm and higher [Reznik et al. 1980; Nitschke 

et al. 1981]. In the Nitschke et al. [1981] 

study, it was also observed that rats exposed 

to 40 ppm for 5 days experienced “eye and 

nasal irritation during the first exposure period.” No other information on these irritative 

effects was provided. It was also reported 

that these irritative effects were not observed 

in other animals. Relative liver weights were 

slightly increased in male rats exposed to 40 

ppm for 6 or 13 weeks and in female rats exposed to 10 ppm (relative liver weight) and 

40 ppm (absolute and relative liver weights). 

Two female rats showed microscopic evidence of slight fatty vacuolation in the liver at 

40 ppm. No other liver adverse effects were 

noted [Nitschke et al. 1981]. In the Resnik et 

al. [1980] study, rats and mice showed severe 

effects in the nasal cavity, including necrosis and atrophy of the nasal epithelium at 75 

ppm; effects were mild at the lower doses (3 

ppm and 15 ppm). Kidney and liver lesions 

were not observed in rats or mice exposed to 

concentrations up to 75 ppm for 6 hours/day, 

5 days/week, for 13 weeks [NTP 1982]. The 

National Toxicology Program (NTP) [1982] 

conducted a carcinogenesis assay of ethylene 

dibromide in rats and mice; neoplasms were 

reported in the nasal cavity and lungs, blood 

vessels, adrenal gland, and mammary gland 

of both species and in the tunica vaginalis in 

rats. Ethylene dibromide is metabolized to 

reactive metabolites that bind to DNA and 

cause gene mutations and other genotoxicity 

[EPA 2008]. These data were not appropriate 

for derivation of an IDLH value.

Two active metabolic pathways are associated 

with exposure to ethylene dibromide. These 

include (1) microsomal oxidation of ethylene dibromide to bromoacetaldehyde via 

the cytochrome P450 pathway, followed by 

a glutathione conjugation reaction, leading to 

the eventual formation of mercapturic acid; 

and (2) a glutathione conjugation reaction 

with ethylene dibromide via the glutathione-S-transferase pathway to form S-2-bromoethylglutathione, leading to the eventual 

formation of mercapturic acid [Sipes et al. 

1986; Ploemen et al. 1997]. The microsomal 

oxidation pathway is thought to be responsible for the acute cytotoxic effects of ethylene 

dibromide via the formation of bromoacetaldehyde, leading to bromine release during 

oxidative metabolism, which initiates cellular lipid peroxidation [IARC 1999]. Physiologically based pharmacokinetic (PBPK) 

modeling suggests that rats produce approximately 4 to 5 times more of the microsomal 

oxidation pathway metabolites than do the 

most sensitive humans [Ploemen et al. 1997]. 

It has also been suggested that both ethanol 

exposure and the use of disulfiram, a medication used to treat alcohol abuse in humans, 

may exacerbate ethylene dibromide toxicity. Chiarpotto et al. [1995] found that oral 

pre-treatment of ethanol in rats potentiated 

the effect of hepatocyte damage caused by 

ethylene dibromide, including increased lipid peroxidation formation, depletion of total 

glutathione, and inactivation of hepatocyte 

total glutathione-transferase. This finding was 

confirmed in another study by Aragno et al. 

[1996], in which rats pre-treated with ethanol 

showed higher levels of liver cytolysis and lipid peroxidation. The authors also found that 

pre-treatment with ethanol also inhibited 

glutathione-s-transferase activity, which likely shifted metabolism of ethylene dibromide 
IDLH Value Profile for Ethylene Dibromide 7

to the microsomal oxidation pathway and led 

to these increased acute effects. Additionally, pre-treatment with disulfiram has been 

associated with increased acute and chronic 

liver toxicity with ethylene dibromide exposure [Aragno et al. 1996; NIOSH 1978; Wong 

1979b]. Aragno et al. [1996] found that the 

acute effects observed (liver cytolysis and lipid peroxidation) were likely due to disulfiram’s 

inhibition of aldehyde dehydrogenase, leading 

to an increased concentration of the intermediate aldehyde metabolites.

The weight of evidence suggests that the 

30-minute time-adjusted NOAELs for lethality for ethylene dibromide in two animal 

species ranged from 456 to 1,317 ppm. The 

LC50 values of ethylene dibromide in two animal species ranged from 727 to 1,861 ppm 

for 30-minute time-adjusted concentrations. 

Irritative effects were noted in some studies; 

however, these effects were not well described 

and could not be used to determine a POD 

to derive an IDLH value. Other repeateddose studies showed similar kidney, liver, 

and nasal effects in multiple animal species 

at similar concentrations, suggesting a similar 

sensitivity to ethylene dibromide across species. For the metabolites responsible for acute 

toxicity associated with ethylene dibromide, 

PBPK modeling results suggest the metabolites are 4 to 5 times higher in rats than in the 

most sensitive humans [Ploemen et al. 1997]. 

Additionally, three rodent studies suggested 

that the liver toxicity associated with ethylene dibromide exposure may be potentiated by pre-exposures to either ethanol or 

disulfiram [Aragno et al. 1996; Chiarpotto et 

al. 1995; NIOSH 1978; Wong 1979b]. These 

co-exposures are an important consideration 

in human exposures to ethylene dibromide. 

The most sensitive species appeared to be rats 

(n = 20), in which a NOAEL for lethality was 

described at 400 ppm of exposure for 36 minutes, resulting in a 30-minute time-adjusted 

concentration of 456 ppm [Rowe 1952]. This 

endpoint was selected as the POD for the 

derivation of the IDLH value. This endpoint 

was selected both because it was the lowest 

NOAEL for lethality and because it closely 

matched the 30-minute time point used for 

IDLH derivation. An alternative approach 

for the derivation of this IDLH value would 

have been based on a 45-minute LC50 value 

of 800 ppm in rats (30-minute concentrationtime-adjusted value, 1,069 ppm) [Rowe et al. 

1952]. However, the use of this POD value 

would have required the application of additional UFs to further account for the derivation from an LC50 value. The resultant IDLH 

value derived from this POD would have 

been similar to the chosen IDLH value.

See section 4 for information regarding the 

derivation of the IDLH value for ethylene dibromide, including additional information on 

the study selected as the POD and the UFs 

applied to derive a final IDLH value.
8 IDLH Value Profile for Ethylene Dibromide 

Table 4. NOAEL (No Observed Adverse Effect Level) Values or Lethality for Ethylene Dibromide

Reference Species

Number of 

animals

NOAEL (lethality) 

(ppm)

Other non-lethal 

effects

Time 

(min)

Adjusted 

30-min Concentration*

(ppm)

Rowe et al. [1952] Rat 20 10000 — 1.2 1003

20 5000 — 2.4 823

20 3000 — 6.0 950

30 1000 — 12 520

20 400 — 36 456‡

5 200 — 120 538

20 100 — 960 1189

Guinea pig 15 200 — 420 1317

20 400 — 120 1077

Koptagel and Bulut [1998] Rat 4 — 1660 60 2724

* For exposures other than 30 minutes, the ten Berge et al. [1986] relationship (Cn × t = k) is used for duration adjustment, where C = concentration, t = time, k = constant, n = time 

scaling value; EPA [2008] provided an empirically estimated n of 1.4 for all time-scaling. Additional information on the calculation of duration-adjusted concentrations can be found in NIOSH [2013]. 

‡ Bolded data are the primary bases of the IDLH value for ethylene dibromide.
IDLH Value Profile for Ethylene Dibromide 9

Table 5. Lethal Concentration Data for Ethylene Dibromide

Reference Species

Number of 

animals

100% Mortality

(ppm)

LC50

(ppm)

Time 

(min)

Adjusted 

30-min Concentration*

(ppm)

Rowe et al. [1952] Rat 74 — 10000 2.4 1642

— — 85 — 5000 5.4 1469

— — 30 — 3000 10.8 1446

— — 80 — 1000 18 1111

— — 80 — 800 45 1069

— — 170 — 400 120 1077— — 122 — 200 720 1077

— — 60 — 100 ND —

Bakhishev [1973] Rat ND — 1861 30 1861

— — — 2902 — 30 2902

Rowe et al. [1952] Guinea pig ND — 400 180 727

Merzbach [1929] Dog 3 2863–14317 — 60 4697–23485

Rowe et al. [1952] Guinea pig 20 400 — 420 2635

Akamine [1952] Rat ND 1000 — 60–105 1641–2447

*For exposures other than 30 minutes, the ten Berge et al. [1986] relationship (Cn × t = k) is used for duration adjustment, where C = concentration, t = time, k = constant, n = time 

scaling value; EPA [2008] provided an empirically estimated n of 1.4 for all time-scaling. Additional information on the calculation of duration-adjusted concentrations can be found in NIOSH [2013].

ND = not determined or no data.
10 IDLH Value Profile for Ethylene Dibromide 

4 Summary

Lethality studies were the only reliable endpoint available on which to base the IDLH 

value for ethylene dibromide. As described 

above, the critical endpoint was determined to be the NOAEL for lethality after 

a 36-minute exposure of rats in the Rowe 

[1952] study. For the metabolites responsible 

for acute toxicity associated with ethylene 

dibromide, PBPK modeling results suggest 

the metabolites are 4 to 5 times higher in 

rats than in the most sensitive humans [Ploemen et al. 1997]. Additionally, rat studies suggested that increased toxicity to ethylene dibromide may occur with pretreatment with 

ethanol or the alcohol treatment medication 

disulfiram, which could be an important consideration in human exposures [Chiarpotto 

et al. 1995; Aragno et al. 1996; Wong 1979b]. 

Limited human data indicate that potentially 

escape-impairing effects (vomiting and respiratory discomfort) occur following exposure 

to approximately 75 ppm ethylene dibromide 

during acute exposures [Ott 1980]. However, these data were not sufficient to serve as a 

POD for an IDLH value. The derived IDLH 

value should also be protective of these severe and non-lethal, escape-impairing effects. An adjusted 30-minute concentration 

was calculated from 36 minutes of exposure 

in a NOAEL for lethality in rats [Rowe et al. 

1952] with a time-adjusted POD of 456 ppm. 

A composite UF of 10 was applied. This was 

composed of a factor of 1 to account for extrapolation from interspecies variability (animal to human) and a factor of 10 to account 

for human variability, resulting in a POD of 

456 ppm divided by a UF of 10 or an IDLH 

value of 46 ppm. The justifications for the underlying component UFs are as follows:

• Interspecies UF (=1)

Similar acute effects were seen across 

rats and guinea pigs at similar concentrations. For the metabolites responsible 

for acute toxicity associated with ethylene dibromide, PBPK modeling results 

suggest the metabolites are 4 to 5 times 

higher in rats than in the most sensitive 

humans; therefore, setting the UF to 1 

errs on the side of protecting workers.

• Intraspecies UF (=10)

This value was selected to account for 

the variability among humans exposed to 

ethylene dibromide. Since the acute toxicity associated with ethylene dibromide 

may be increased with co-exposure to 

ethanol or disulfiram (a medication used 

to treat alcoholism in humans), and the 

distribution of these exposures in worker 

populations is unknown, a 10-fold UF is 

reasonable to account for increased sensitivity to ethylene dibromide toxicity in 

some workers.
IDLH Value Profile for Ethylene Dibromide 11

5 References

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limit values) and BEIs® (biological exposure 

indices) booklet. Cincinnati, OH: ACGIH 

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AIHA [2016]. Emergency response planning 

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Fairfax, VA: American Industrial Hygiene 

Association Press.

Akamine EK [1952]. Toxicity of ethylene dibromide to white rats. Progress notes no. 83. 

Makiki, HI: Hawaii Agricultural Experiment 

Station of the University of Hawaii. 

Aragno M, Tamagno E, Danni O, Chiarpotto E, Biasi F, Scavazza A, Albano E, Poli G, 

Dianzani MU [1996]. In vivo potentiation 

of 1,2-dibromoethane hepatotoxicity by ethanol through inactivation of glutathione-stransferase. Chemico-Biological Interactions 

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Bakhishev GN [1973]. Relative toxicity of aliphatic halohydrocarbons to rats [in Russian]. 

Farmakol Toksikol 8:140–143. 

Chiarpotto E, Biasi F, Aragno M, Scavazza A, 

Danni O, Dianzani MU, Poli G [1995]. Ethanol-induced potentiation of rat hepatocyte 

damage due to 1, 2-dibromoethane. Alcohol 

and Alcoholism 30(1):37–45.

EPA [2008]. Interim Acute Exposure Guideline Levels (AEGLs) for 1,2-dibromoethane. 

Washington, DC: Environmental Protection 

Agency, https://www.epa.gov/sites/production/files/2014-08/documents/1_2_dibromoethane_tsd_interim_5_2008_v1.pdf.

EPA [2019]. Integrated Risk Information System (IRIS): glossary. Washington, DC: Environmental Protection Agency, https://ofmpub.

epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.

do?details=&glossaryName=IRIS%20Glossary#formTop. 

IARC [1999]. Ethylene dibromide. In: IARC 

monographs on the evaluation of the carcinogenic risk to humans: re-evaluation of some 

organic chemicals, hydrazine and hydrogen 

peroxide. Volume 71, Pt. 2. Lyon, France: World 

Health Organization, International Agency for 

Research on Cancer, pp. 641–669.

IFA [2019]. GESTIS: database on hazardous substances. Bonn, Germany: Institut für 

Arbeitsschutz der Deutschen Gesetzlichen 

Unfallversicherung, http://gestis-en.itrust.de/

nxt/gateway.dll?f=templates&fn=default.htm&vid=gestiseng:sdbeng.

Koptagel E, Bulut HE [1998]. Effects of shortterm hydrocarbon inhalation on rat tracheal 

mucosa. Okajimas Folia Anat Jpn 75(2–3):

71–86.

Letz GA, Pond SM, Osterloh JD, Wade RL, 

Becker CE [1984]. Two fatalities after acute 

occupational exposure to ethylene dibromide. 

JAMA 252:2428–2431.

Merzbach L [1929]. The pharmacology of 

methyl bromide and related compounds [in 

German]. Z Gesamte Exp Med 63:383–392.

NIOSH [1977]. NIOSH criteria for a recommended standard: occupational exposure to 

ethylene dibromide. By Debbs G, Chandler 

JLR. Cincinnati, OH: U.S. Department of 

Health, Education, and Welfare, Center for 

Disease Control, National Institute for Occupational Health, DHEW (NIOSH) Publication No. 77-221.

NIOSH [1978]. Current Intelligence Bulletin 

23: ethylene dibromide and disulfiram toxic 

interaction. Cincinnati, OH: U.S. Department 

of Health, Education, and Welfare, Center 
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(NIOSH) Publication No. 78-145. 

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logic. By Bollinger N. Cincinnati, OH: U.S. 

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risk assessment of hazardous compounds: 

the case of ethylene dibromide. Toxicol Appl 

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Semen quality in papaya workers with long 

term exposure to ethylene dibromide. Br J 

Ind Med 44:317–326.

Reznik G, Stinson SF, Ward JM [1980]. Respiratory pathology in rats and mice after inhalation of 1,2-dibromo-3-chloropropane or 

1,2-dibromoethane for 13 weeks. Arch Toxicol 46:233–240.

Rowe VK, Spencer HC, McCollister DD, 

Hollingsworth RL, Adams EM [1952]. Toxicity of ethylene dibromide determined on 

experimental animals. Arch Ind Hyg Occup 

Med 6:158–173.

Schrader SM, Ratcliffe JM, Turner TW, 

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Schrader SM, Turner TW, Ratcliffe JM [1988]. 

The effects of ethylene dibromide on semen 

quality: a comparison of short-term and chronic exposure. Reprod Toxicol 2:191–198.

Sipes IG, Wiersma DA, Armstrong DJ [1986]. 

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1,2-dibromoethane by glutathione. Adv Exp 

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Concentration-time mortality response relationship of irritant and systematically acting 

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science: workplace environmental exposure 

levels (WEEL). Cincinnati, OH: Toxicology 

Excellence for Risk Assessment, https://www.

tera.org/OARS/WEEL.html.

Wong O, Utidjian HM, Karten VS [1979a]. 

Retrospective evaluation of reproductive 

performance of workers exposed to ethylene 

dibromide (EDB). J Occup Med 21:98–102.

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of 1,2-dibromoethane in rats with and without dietary disulfiram. PB82195603. Kansas 

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14 IDLH Value Profile for Ethylene Dibromide 

Appendix A. Literature Search Strategy and 

Data Evaluation

As described in CIB 66 [NIOSH 2013], NIOSH 

performed in-depth literature searches to identify all relevant data from human and animal 

studies with acute exposures to the substance. For ethylene dibromide, this process 

included reviewing toxicity summaries and 

acute exposure guidelines during an initial 

screening approach, including the AEGL documentation [EPA 2008], ACGIH TLV® documentation [ACGIH 2020], and NIOSH 1994 

IDLH documentation [NIOSH 1994]. Studies were identified from these summaries, 

and additional database queries were conducted in the databases listed in Table A-1. 

Search terms used in these databases are 

provided in Table A-2. For ethylene dibromide, the chemical identifiers used in the database searches were “ethylene dibromide,” 

“dibromoethane,” “EDB,” and “CAS Registry 

Number: 106-93-4.” An in-depth literature 

search was conducted through June 2019. 

The information identified in this search was 

evaluated with general considerations that 

included description of studies (i.e., species, 

study protocol, exposure concentration and 

duration), health endpoint evaluated, and 

critical effect levels (e.g., NOAELs, LOAELs, 

and LC50 values). Fifty-nine primary and secondary references were identified in the literature search and 17 primary references were 

cited in the IDLH document. These references included both peer reviewed literature and 

scientific reports. The references that were 

not cited did not provide primary or relevant 

secondary data on ethylene dibromide. 
IDLH Value Profile for Ethylene Dibromide 15

Table A–1. Literature search sources 

Database Link 

Centers for Disease Control and Prevention (CDC)/Agency for Toxic Substances 

and Disease Registry (ATSDR) ToxProfiles 

https://www.atsdr.cdc.gov/toxprofiledocs/index.html

ChemIDplus https://chem.sis.nlm.nih.gov/chemidplus/chemidlite.jsp

EU, European INventory of Existing 

Commercial chemical Substances 

(EINECS) 

https://ihcp.jrc.ec.europa.eu/our_labs/predictive_ 

toxicology/information-sources/ec_inventory

EMBASE https://www.embase.com/

Hazardous Substances Data Bank 

(HSDB)

https://www.nlm.nih.gov/databases/download/hsdb.

html

Haz-map https://haz-map.com/

National Library of Medicine (NLB) https://pubchem.ncbi.nlm.nih.gov/

International Agency for Research on 

Cancer (IARC) 

https://www.iarc.fr/

Environmental Protection Agency (EPA) 

Toxic Substance Control Act (TSCA) 

Section 8(e) Notices 

https://www.epa.gov/chemicals-under-tsca

World Health Organization (WHO)/IPCS 

International Chemical Safety Card (ICSC) 

https://www.ilo.org/safework/lang--en/index.htm

International Toxicity Estimates for Risk 

(ITER) 

https://tera.org/iter/

New Jersey Hazardous Substance Fact 

Sheets (NJ-HSFS) 

https://web.doh.state.nj.us/rtkhsfs/indexfs.aspx

NIOSHTIC-2 https://www2a.cdc.gov/nioshtic-2/default.asp

NLM, PUBMED https://pubmed.ncbi.nlm.nih.gov/

National Institute for Occupational 

Safety and Health (NIOSH)/Registry of 

Toxic Effects of Chemical Substances 

(RTECS) 

https://www.cdc.gov/niosh/rtecs/

NLM, Toxicology Literature Online 

(TOXLINE) 

https://pubmed.ncbi.nlm.nih.gov/?term=tox%20[subset]%20AND

Scopus https://www.scopus.com/search/form.uri?display=basic
16 IDLH Value Profile for Ethylene Dibromide 

Table A–2. Literature search key words 

Search terms

Acute Fatal Threshold 

Inhalation Fatality Case study

Lethal Irritation Poisoning 

Lethal concentration Respiratory Chemical identifiers 

LC RD

References

ACGIH (American Conference of Governmental Industrial Hygienists) [2020]. Documentation of the threshold limit values and biological 

exposure indices, 7th edition–2020 supplement. 

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acgih.org/forms/store/ProductFormPublic/documentation-of-the-threshold-limit-values-and-biological-exposure-indices-7th-ed-2020-supplement. Date accessed: January 8, 2020.

EPA [2008]. Interim acute exposure guideline levels (AEGLs) for 1,2-dibromoethane. 

Washington, DC: Environmental Protection Agency, https://www.epa.gov/sites/

production/files/2014-08/documents/1_2_

dibromoethane_tsd_interim_5_2008_

v1.pdf. Date accessed: September 20, 2019.

NIOSH [2013]. Current Intelligence Bulletin 66: derivation of immediately dangerous 

to life or health (IDLH) values. Cincinnati, 

OH: U.S. Department of Health and Human 

Services, Centers for Disease Control and 

Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) 

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and Human Services, Centers for Disease 

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DOI: https://doi.org/10.26616/NIOSHPUB2020125

Promoting productive workplaces through safety 

and health research