External Review Draft 

March 2015 

i

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1

2

3

4

5

6

7 IMMEDIATELY DANGEROUS TO LIFE OR HEALTH (IDLH) VALUE PROFILE 

8

9

10

11 FOR 

12

13

14

15 N-BUTYL ACRYLATE 

16

17

18

19 [CAS NO. 141-32-2]

20

21

22

23

24

25

26 Department of Health and Human Services 

27 Centers for Disease Control and Prevention 

28 National Institute for Occupational Safety and Health 
 External Review Draft 

March 2015 

ii

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 DISCLAIMER

2 Mention of any company or product does not constitute endorsement by the National Institute for Occupational 

3 Safety and Health (NIOSH). In addition, citations of Web sites external to NIOSH do not constitute NIOSH 

4 endorsement of the sponsoring organizations or their programs or products. Furthermore, NIOSH is not 

5 responsible for the content of these Web sites. 

6

7 ORDERING INFORMATION

8 This document is in the public domain and may be freely copied or reprinted. To receive NIOSH documents or 

9 other information about occupational safety and health topics, contact NIOSH at 

10 Telephone: 1-800-CDC-INFO (1-800-232-4636) 

11 TTY: 1-888-232-6348 

12 E-mail: cdcinfo@cdc.gov 

13

14 or visit the NIOSH Web site at www.cdc.gov/niosh. 
 External Review Draft 

March 2015 

iii

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Foreword 

2 Chemicals are a ubiquitous component of the modern workplace. Occupational exposures to chemicals have the 

3 potential to adversely affect the health and lives of workers. Acute or short-term exposures to high concentrations 

4 of some airborne chemicals have the ability to quickly overwhelm workers, resulting in a spectrum of undesirable 

5 health outcomes that may inhibit the ability to escape from the exposure environment (e.g., irritation of the eyes 

6 and respiratory tract or cognitive impairment), cause severe irreversible effects (e.g., damage to the respiratory 

7 tract or reproductive toxicity), and in extreme cases, cause death. Airborne concentrations of chemicals capable 

8 of causing such adverse health effects or of impeding escape from high-risk conditions may arise from a variety of 

9 non-routine workplace situations , including special work procedures (e.g., in confined spaces), industrial 

10 accidents (e.g., chemical spills or explosions), and chemical releases into the community (e.g., during 

11 transportation incidents or other uncontrolled-release scenarios). 

12

13 The “immediately dangerous to life or health air concentration values (IDLH values)” developed by the National 

14 Institute for Occupational Safety and Health (NIOSH) characterize these high-risk exposure concentrations and 

15 conditions [NIOSH 2013]. IDLH values are based on a 30-minute exposure duration and have traditionally 

16 served as a key component of the decision logic for the selection of respiratory protection devices [NIOSH 2004]. 

17 Occupational health professionals have employed these values beyond their initial purpose as a component of the 

18 NIOSH Respirator Selection Logic to assist in developing Risk Management Plans for non-routine work practices 

19 governing operations in high-risk environments (e.g., confined spaces) and the development of Emergency 

20 Preparedness Plans. 

21

22 The approach used to derive IDLH values for high priority chemicals is outlined in the NIOSH Current 

23 Intelligence Bulletin (CIB) 66: Derivation of Immediately Dangerous to Life or Health Values [NIOSH 2013]. 

24 CIB 66 provides 1) an update on the scientific basis and risk assessment methodology used to derive IDLH 

25 values, 2) the rationale and derivation process for IDLH values, and 3) a demonstration of the derivation of 

26 scientifically credible IDLH values using available data resources.

27

28 The purpose of this technical report is to present the IDLH value for n-butyl acrylate (CAS # 141-23-2). The 

29 scientific basis, toxicologic data and risk assessment approach used to derive the IDLH value are summarized to 

30 ensure transparency and scientific credibility. 

31 

32 John Howard, M.D. 

33 Director 

34 National Institute for Occupational Safety and Health 
 External Review Draft 

March 2015 

iv

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Centers for Disease Control and Prevention
 External Review Draft 

March 2015 

v

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Contents 

2 FOREWORD ................................................................................................................................................................ III

3 ABBREVIATIONS .......................................................................................................................................................VI

4 GLOSSARY .................................................................................................................................................................VII

5 ACKNOWLEDGMENTS .............................................................................................................................................XI

6 1.0 INTRODUCTION.............................................................................................................................................. 1

7 1.1 OVERVIEW OF THE IDLH VALUE FOR N-BUTYL ACRYLATE .......................................................................................1

8 1.2 PURPOSE .....................................................................................................................................................................1

9 1.3 GENERAL SUBSTANCE INFORMATION .........................................................................................................................1

10 2.0 ANIMAL TOXICITY DATA............................................................................................................................. 4

11 3.0 HUMAN DATA ................................................................................................................................................. 7

12 4.0 SUMMARY........................................................................................................................................................ 7

13 5.0 REFERENCES .................................................................................................................................................. 8

14

15

16

17

18
 External Review Draft 

March 2015 

vi

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Abbreviations 

2

3 ACGIH American Conference of Governmental Industrial Hygienists 

4 AEGL Acute Exposure Guideline Levels 

5 AIHA American Industrial Hygiene Association 

6 BMC benchmark concentration 

7 BMCL benchmark concentration lower confidence limit 

8 C° Celsius 

9 C ceiling 

10 CAS chemical abstract service 

11 ERPG Emergency Response Planning Guidelines 

12 IDLH immediately dangerous to life or health 

13 LC50 median lethal concentration 

14 LCLo lowest concentration of a chemical that caused death in humans or animals 

15 LEL lower explosive limit 

16 LOAEL lowest observed adverse effect level 

mg/m3 17 milligram(s) per cubic meter 

18 mmHg millimeter(s) of mercury 

19 NAC National Advisory Committee 

20 NAS National Academy of Sciences 

21 NIOSH National Institute for Occupational Safety and Health 

22 NOAEL no observed adverse effect level 

23 OSHA Occupational Safety and Health Administration 

24 PEL permissible exposure limit 

25 ppm parts per million 

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

27 rate 

28 REL recommend exposure limit 

29 SCP Standard Completion Program 

30 STEL short term exposure limit 

31 TLV threshold limit value 

32 TWA time weighted average 

33 UEL upper explosive limit 

34 WEEL workplace environmental exposure level 
 External Review Draft 

March 2015 

vii

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Glossary 

2

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

4 Acute Exposure Guideline Levels (AEGLs): Threshold exposure limits for the general public applicable to 

5 emergency exposure periods ranging from 10 minutes to 8 hours. AEGL-1, AEGL 2, and AEGL-3 are 

6 developed for five exposure periods (10 and 30 minutes, 1 hour, 4 hours, and 8 hours) and are distinguished 

7 by varying degrees of severity of toxic effects ranging from transient, reversible effects to life-threatening 

8 effects [NAS 2001]. AEGLs are intended to be guideline levels used during rare events or single once-in-a9 lifetime exposures to airborne concentrations of acutely toxic, high-priority chemicals [NAS 2001]. The 

10 threshold exposure limits are designed to protect the general population, including the elderly, children or 

11 other potentially sensitive groups that are generally not considered in the development of workplace exposure 

12 recommendations (additional information available at http://www.epa.gov/oppt/aegl/). 

13 Acute Reference Concentration (RfC): An estimate (with uncertainty spanning perhaps an order of magnitude) 

14 of a continuous inhalation exposure for an acute duration (24 hours or less) of the human population 

15 (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a 

16 lifetime. It can be derived from a NOAEL, LOAEL, or benchmark concentration, with uncertainty factors 

17 (UFs) generally applied to reflect limitations of the data used. Generally used in USEPA noncancer health 

18 assessments [USEPA 2014]. 

19 Acute Toxicity: Any poisonous effect produced within a short period of time following an exposure, usually 24 

20 to 96 hours. 

21 Adverse Effect: A substance-related biochemical change, functional impairment, or pathologic lesion that affects 

22 the performance of an organ or system or alters the ability to respond to additional environmental challenges. 

23 Benchmark Dose/Concentration (BMD/BMC): A dose or concentration that produces a predetermined change 

24 in response rate of an effect (called the benchmark response, or BMR) compared to background [USEPA 

25 2014] (additional information available at http://www.epa.gov/ncea/bmds/). 

26 Benchmark Response (BMR): A predetermined change in response rate of an effect. Common defaults for the 

27 BMR are 10% or 5%, reflecting study design, data variability, and sensitivity limits used. 

28 BMCL: A statistical lower confidence limit on the concentration at the BMC [USEPA 2014]. 

29 Bolus Exposure: A single, relatively large dose. 

30 Ceiling Value (“C”): U.S. term in occupational exposure indicating the airborne concentration of a potentially 

31 toxic substance that should never be exceeded in a worker’s breathing zone. 

32 Chronic Exposure: Repeated exposure for an extended period of time. Typically exposures are more than 

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

34 Critical Study: The study that contributes most significantly to the qualitative and quantitative assessment of risk 

35 [USEPA 2014]. 

36

37 Dose: The amount of a substance available for interactions with metabolic processes or biologically significant 

38 receptors after crossing the outer boundary of an organism [USEPA 2014]. 

39 ECt50: A combination of the effective concentration of a substance in the air and the exposure duration that is 

40 predicted to cause an effect in 50% (one half) of the experimental test subjects. 
 External Review Draft 

March 2015 

viii

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Emergency Response Planning Guidelines (ERPGs): Maximum airborne concentrations below which nearly all 

2 individuals can be exposed without experiencing health effects for 1-hour exposure. ERPGs are presented in a 

3 tiered fashion with health effects ranging from mild or transient to serious, irreversible, or life threatening 

4 (depending on the tier). ERPGs are developed by the American Industrial Hygiene Association [AIHA 2006]. 

5 Endpoint: An observable or measurable biological event or sign of toxicity ranging from biomarkers of initial 

6 response to gross manifestations of clinical toxicity. 

7 Exposure: Contact made between a chemical, physical, or biological agent and the outer boundary of an 

8 organism. Exposure is quantified as the amount of an agent available at the exchange boundaries of the 

9 organism (e.g., skin, lungs, gut). 

10 Extrapolation: An estimate of the response at a point outside the range of the experimental data, generally 

11 through the use of a mathematical model, although qualitative extrapolation may also be conducted. The 

12 model may then be used to extrapolate to response levels that cannot be directly observed. 

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

14 specific exposure conditions. 

15 Immediately Dangerous to Life or Health (IDLH) condition: A situation that poses a threat of exposure to 

16 airborne contaminants when that exposure is likely to cause death or immediate or delayed permanent adverse 

17 health effects or prevent escape from such an environment [NIOSH 2004, 2013]. 

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

19 providing maximum worker protection is permitted [NIOSH 2004, 2013]. IDLH values are based on a 30-

20 minute exposure duration. 

21 LC01: The statistically determined concentration of a substance in the air that is estimated to cause death in 1% of 

22 the test animals. 

23 LC50: The statistically determined concentration of a substance in the air that is estimated to cause death in 50% 

24 (one half) of the test animals; median lethal concentration. 

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

26 percentage of the test animals. 

27

28 LD50: The statistically determined lethal dose of a substance that is estimated to cause death in 50% (one half) of 

29 the test animals; median lethal concentration. 

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

31 LEL: The minimum concentration of a gas or vapor in air, below which propagation of a flame does not occur in 

32 the presence of an ignition source. 

33 Lethality: Pertaining to or causing death; fatal; referring to the deaths resulting from acute toxicity studies. May 

34 also be used in lethality threshold to describe the point of sufficient substance concentration to begin to cause 

35 death. 

36 Lowest Observed Adverse Effect Level (LOAEL): The lowest tested dose or concentration of a substance that 

37 has been reported to cause harmful (adverse) health effects in people or animals. 
 External Review Draft 

March 2015 

ix

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Mode of Action: The sequence of significant events and processes that describes how a substance causes a toxic 

2 outcome. Mode of action is distinguished from the more detailed mechanism of action, which implies a more 

3 detailed understanding on a molecular level. 

4 No Observed Adverse Effect Level (NOAEL): The highest tested dose or concentration of a substance that has 

5 been reported to cause no harmful (adverse) health effects in people or animals. 

6 Occupational Exposure Limit (OEL): Workplace exposure recommendations developed by governmental 

7 agencies and non-governmental organizations. OELs are intended to represent the maximum airborne 

8 concentrations of a chemical substance below which workplace exposures should not cause adverse health 

9 effects. OELs may apply to ceiling, short-term (STELs), or time-weighted average (TWA) limits. 

10 Peak Concentration: Highest concentration of a substance recorded during a certain period of observation. 

11 Permissible Exposure Limit (PEL): Occupational exposure limits developed by OSHA (29 CFR 1910.1000) or 

12 MSHA (30 CFR 57.5001) for allowable occupational airborne exposure concentrations. PELs are legally 

13 enforceable and may be designated as ceiling, STEL, or TWA limits. 

14

15 Point of Departure (POD): The point on the dose–response curve from which dose extrapolation is initiated. 

16 This point can be the lower bound on dose for an estimated incidence or a change in response level from a 

17 concentration-response model (BMC), or it can be a NOAEL or LOAEL for an observed effect selected from 

18 a dose evaluated in a health effects or toxicology study. 

19 RD50: The statistically determined concentration of a substance in the air that is estimated to cause a 50% (one 

20 half) decrease in the respiratory rate. 

21 Recommended Exposure Limit (REL): Recommended maximum exposure limit to prevent adverse health 

22 effects based on human and animal studies and established for occupational (up to 10-hour shift, 40-hour 

23 week) inhalation exposure by NIOSH. RELs may be designated as ceiling, STEL, or TWA limits. 

24 Short-Term Exposure Limit (STEL): A worker’s 15-minute time-weighted average exposure concentration that 

25 shall not be exceeded at any time during a work day. 

26 Target Organ: Organ in which the toxic injury manifests in terms of dysfunction or overt disease. 

27 Threshold Limit Values (TLVs®): Recommended guidelines for occupational exposure to airborne 

28 contaminants, published by the American Conference of Governmental Industrial Hygienists (ACGIH). TLVs 

29 refer to airborne concentrations of chemical substances and represent conditions under which it is believed 

30 that nearly all workers may be repeatedly exposed, day after day, over a working lifetime, without adverse 

31 effects. TLVs may be designated as ceiling, short-term (STELs), or 8-hr TWA limits. 

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

33 concentration that shall not be exceeded during an 8-hour (or up to 10-hour) work shift of a 40-hour week. 

34 The average concentration is weighted to take into account the duration of different exposure concentrations. 

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

36

37 Uncertainty Factors (UFs): Mathematical adjustments applied to the POD when developing IDLH values. The 

38 UFs for IDLH value derivation are determined by considering the study and effect used for the POD, with 

39 further modification based on the overall database. 
 External Review Draft 

March 2015 

x

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Workplace Environmental Exposure Levels (WEELs): Exposure levels developed by the American Industrial 

2 Hygiene Association (AIHA) that provide guidance for protecting most workers from adverse health effects 

3 related to occupational chemical exposures expressed as a TWA or ceiling limit.

4 
 External Review Draft 

March 2015 

xi

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 Acknowledgments 

2

3 This document was developed by the Education and Information Division (Paul Schulte, Ph.D., Director). G. 

4 Scott Dotson, Ph.D., was the project officer and lead NIOSH author for this technical report. The basis for this 

5 document was a report contracted by NIOSH and prepared by Andrew Maier, Ph.D., Ann Parker, and Lynn 

6 Haber, Ph.D. (Toxicology Excellence for Risk Assessment [TERA]). 

7

8 Education and Information Division 

9 Devin Baker, M.Ed. 

10 Charles L. Geraci, Ph.D. 

11 Thomas J. Lentz, Ph.D. 

12 Richard Niemeier, Ph.D. 

13 Chris Sofge, Ph.D. 

14

15 NIOSH would like to acknowledge the contribution of the following subject matter experts for their critical 

16 technical review of this report. 

17

18 Mary A. Fox, Ph.D., Assistant Professor; Co-Director, Risk Sciences and Public Policy Institute; 

19 Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins 

20 University 

21

22 Richard B. Schlesinger, Ph.D., Fellow A.T.S., Senior Associate Dean for Academic Affairs and Research 

23 Professor of Biology, Dyson College of Arts and Sciences, Pace University 
 External Review Draft 

March 2015 

1

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 1.0 Introduction 

2 1.1 Overview of the IDLH Value for n-Butyl Acrylate 

3

4 IDLH Value: 113 ppm

5

6 Basis for IDLH Value: The IDLH value for n-butyl acrylate is based on the 30-minute RD50 (concentration 

7 estimated to result in a 50% depression in breathing rate) of 340 ppm in mice [Kirkpatrick 2003]. This effect is 

8 classified as potentially escape impairing. Application of an uncertainty factor of 3 to account for extrapolation 

9 from a threshold for escape-impairing effects in animals, animal to human differences, and human variability, 

10 results in an IDLH value of 113 ppm.

11

12 1.2 Purpose 

13

14 This IDLH Profile presents (1) a brief summary of technical data associated with acute inhalation exposures to n15 butyl acrylate and (2) the rationale behind the Immediately Dangerous to Life or Health (IDLH) value for n-butyl 

16 acrylate. IDLH values are developed based on the scientific rationale and logic outlined in the NIOSH Current 

17 Intelligence Bulletin (CIB) 66: Derivation of Immediately Dangerous to Life or Health (IDLH) values [NIOSH 

18 2013]. As described in CIB 66, NIOSH performs in-depth literature searches to ensure that all relevant data from 

19 human and animal studies with acute exposures to the substance are identified. Information included in CIB 66 on 

20 the literature search includes pertinent databases, key terms, and guides for evaluating data quality and relevance 

21 for the establishment of an IDLH value. The information that is identified in the in-depth literature search is 

22 evaluated with general considerations that include description of studies (i.e., species, study protocol, exposure 

23 concentration and duration), health endpoint evaluated, and critical effect levels (e.g., NOAELs, LOAELs, LC50

24 values). For n-butyl acrylate, the in-depth literature search was conducted through February 2014. 

25

26 1.3 General Substance Information 

27

28 Chemical: n-Butyl acrylate 

29

30 CAS No: 141-32-2 

31

Synonyms: 2-Propenoic acid butyl ester; Acrylic acid butyl ester (8Cl); Butyl acrylate* 32

33
 External Review Draft 

March 2015 

2

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

Chemical category: Carboxylic acid esters† 1

2

3

4

5 Structural formula:

6

7

8

9 Table 1 highlights selected physiochemical properties of n-butyl acrylate relevant to IDLH conditions. Table 2 

10 provides alternative exposure guidelines for n-butyl acrylate. Table 3 summarizes the Acute Exposure Guidelines 

11 Level (AEGL) values for n-butyl acrylate.

12

13 Table 1: Physiochemical Properties of n-Butyl Acrylate 

14

Property Value 

Molecular weight 128.17‡

Chemical formula C7H12O2

Description Colorless liquid 

Odor Strong, fruity; Rancid; Plastic

Odor Threshold 0.00096-0.10 ppm*

UEL 8%†

LEL 1.2%†

Vapor pressure 5.45 mmHg at 25°C (77°F)‡

Flash point 28.89°C (84°F)‡

Ignition temperature 292.78°C (559°F)‡

Solubility Slightly soluble in water†

15 Abbreviation: °C – Celsius; °F – Fahrenheit; mmHg – millimeter mercury; LEL – lower explosive limit; UEL – upper explosive limit 

‡

HSDB [2014], *AEGL [2007]; † 16 IFA [2014] 

17

18 Table 2: Alternative Exposure Guidelines for n-Butyl Acrylate 

19

Organization Value 

Original (SCP) IDLH value None 

NIOSH REL 10 ppm (55 mg/m3), TWA 

OSHA PEL [2014] 10 ppm (55 mg/m3

), TWA 8-hr 

ACGIH TLV [2014] 2 ppm, TWA 

AIHA ERPG [2010] ERPG-1: 0.05 ppm; ERPG-2: 25 ppm; ERPG-3: 250 ppm 

AIHA WEEL [2010] Not available 

20 Abbreviation: ACGIH – American Conference of Governmental Industrial Hygienists; AIHA – American Industrial Hygiene 

21 Association; ERPG – Emergency Response Preparedness Guidelines; IDLH – immediately dangerous to life or health; NIOSH – National 

22 Institute for Occupational Safety and Health; OSHA – Occupational Safety and Health Administration; PEL – permissible exposure limit; 

23 REL – recommended exposure limit; SCP – Standards Completion Program; WEEL – workplace environmental exposure level 

24 

H2C

O CH3

O
 External Review Draft 

March 2015 

This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guid

formally disseminated by the National Institute for Occupational Safety and Health. It does not represent and should not be con

agency determination or policy. 

1 Table 3: AEGL Values for n-Butyl Acrylate 

2

Classification 10-min 30-min 1-hour 4-hour 8-hour Endpoint [AEGL-1 8.3 ppm 

44.0 mg/m3

8.3 ppm 44.0 mg/m3

8.3 ppm 44.0 mg/m3

8.3 ppm 44.0 mg/m3

8.3 ppm 44.0 mg/m3

No clinicaexposures Merkle an

AEGL-2 160.0 ppm 

850.0 mg/m3

160.0 ppm 850.0 mg/m3

130.0 ppm 690.0 mg/m3

81.0 ppm 430.0 mg/m3

53.0 ppm 280.0 mg/m3

Clinical sirepeated e[Klimisch 

AEGL-3 820.0 ppm 

4,400.0 mg/m3

820.0 ppm 4,400.0 mg/m3

480.0 ppm 2,600.0 mg/m3

170.0 ppm 906.0 mg/m3

97.0 ppm 520.0 mg/m3

Calculated 

[Oberly an

Abbreviation: AEGL – acute exposure guideline levels; mg/m3 3 – milligrams per cubic meter; min – minute; NR – not recommended due to inadequate da* 4 References: NAS [2007]
 External Review Draft 

March 2015 

4

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 2.0 Animal Toxicity Data 

2

3 The available data on n-butyl acrylate lethality and toxicity are limited. LC50 values were not substantially 

4 different among hamsters, rats, and mice. Engelhardt and Klimisch [1983] exposed hamsters and rats to n-butyl 

5 acrylate for 6 hours/day for 4 days at concentrations of 817 and 820 ppm, respectively. Clinical signs, dyspnea, 

6 disequilibrium, and bloody discharge from the eyes and noses were observed; no deaths occurred in rats, however, 

7 four male hamsters died during the exposure period. N-butyl acrylate caused clinical signs of irritation in all 

8 species tested. 

9

10 The most reliable animal lethality data came from the Oberly and Tansy [1985] 4-hour LC50 study in rats. Male 

11 Sprague-Dawley rats were exposed whole body for 4 hours to 1,990, 2,035, 2,500, 2,828, or 3,041 ppm n-butyl 

12 acrylate followed by a 14-day observation period. Vapor concentration was determined by gas chromatography. 

13 During exposures animals had normal behavior during the first few minutes, then exhibited irritation of the eyes, 

14 nose, and respiratory tract and labored breathing. All deaths occurred within 24 hours and were attributed to 

15 cardiopulmonary collapse. The number of deaths at each concentration was 0, 1, 3, 5, and 7, respectively. The 4-

16 hour LC50 was calculated as 2,730 ppm. NAS [2007] calculated a 4-hour lethality BMCL05 value (a statistical 

17 lower confidence limit on the dose that produces a predetermined change in response rate of an adverse effect) by 

18 log-probit analysis using US EPA Benchmark Dose Software version 1.3.2. The resulting 4-hour BMCL05 of 

19 1,652 ppm was adjusted to a 30-minute exposure duration concentration of 8,179 ppm. Kirkpatrick [2003] 

20 measured respiratory depression in mice; the lowest effect level for respiratory depression was 100 ppm, the no 

21 effect level was 30 ppm, and the calculated RD50 was 340 ppm. In a 4-hour LC50 study in rats, BASF [1979b,c; 

22 1980] reported severe irritation at 677 ppm. 

23

24 Table 4 summarizes the LC data identified in animal studies and provides 30-minute equivalent derived values for 

25 n-butyl acrylate. Table 5 provides non-lethal data reported in animal studies with 30-minute equivalent derived 

26 values. Information in this table includes species of test animals, toxicological metrics (i.e., LC, NOAEL, 

27 LOAEL), adjusted 30-minute concentration, and the justification for the composite uncertainty factors applied to 

28 calculate the derived values. 
 External Review Draft 

March 2015 

This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guid

formally disseminated by the National Institute for Occupational Safety and Health. It does not represent and should not be con

agency determination or policy. 

1 Table 4: Lethal Concentration Data for n-Butyl Acrylate2

Reference Species LC50

(ppm) 

LC10

(ppm) 

Time (min) 

Adjusted 30-min Concentration* 

CompoUncertFactor 

BASF [1979a] Hamster 1,201 -- 240 5,946 30‡ BASF [1979a] Mouse 1,278 -- 240 6,327 30‡ Oberly and Tansy [1985] Rat 2,730 -- 240 13,516 30‡ 

Oberly and Tansy [1985] Rat -- 1,652 240 8,179 10± 

BASF [1979b,c; 1980] Rat 1,936 -- 240 9,585 30‡ 

34 Abbreviation: LC – lethal concentration; LC10 – concentration estimated to cause a 10% mortality rate; LC50 – median lethal concentration5 of a chemical that caused death in humans or animals; min – minute; ppm – parts per million 

* 6 NAS [2007] empirically estimated n = 1.3 by combining 1- and 4- hour LC50 data sets from ethyl acrylate in a 3-dimensional probit analysi

7 all duration adjustments for n-butyl acrylate. 8 †The derived value is the result of the adjusted 30-minute LC value divided by the composite uncertainty factor. 9 ‡Composite uncertainty factor to account for adjustment of LC50 values to LC01 values, use of lethal concentration threshold in animals, inte

10 human variability. 

± 11 Composite uncertainty factor to account for lethal concentration threshold in animals, interspecies differences and human variability. 

12 extrapolation from a threshold for escape-impairing effects in animals, animal to human differences, and human variability
 External Review Draft 

March 2015 

This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guid

formally disseminated by the National Institute for Occupational Safety and Health. It does not represent and should not be con

agency determination or policy. 

1 Table 5: Non-lethal Concentration Data for n-Butyl Acrylate2

Reference Species NOAEL 

(ppm) 

LOAEL (ppm) 

Time (min) 

Adjusted 30-min Concentration* 

CompoUncertFactor 

Kirkpatrick [2003]+ Mouse -- 340‡ 30 340 3± 

34 Abbreviation: NOAEL – no observed adverse effect level; min – minute; LOAEL – lowest observed adverse effect level; ppm – parts per 

* 5 NAS [2007] empirically estimated n = 1.3 by combining 1- and 4- hour LC50 data sets from ethyl acrylate in a 3-dimensional probit analysi

6 all duration adjustments for n-butyl acrylate. 7 †The derived value is the result of the adjusted 30-min value divided by the composite uncertainty factor. The composite uncertainty factor 8 based on the nature and severity of the endpoint observed. 

+ 9 Identified study is the primary basis of the IDLH value for n-butyl acrylate. ‡ 10 This concentration was determined to be a RD50 (concentration estimated to result in a 50% depression in breathing rate). ± 11 Composite uncertainty factor to account for extrapolation from a threshold for escape-impairing effects in animals, animal to human differe

12
 External Review Draft 

March 2015 

7

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 3.0 Human Data 

2

3 No reports of human fatalities from exposure to n-butyl acrylate were found. Very little information is available 

4 concerning human exposure to n-butyl acrylate. Symptoms of irritation were occasionally reported in chemical 

5 plant workers [Tucek et al. 2002]. Dermal sensitization has been reported [BIBRA 1991], but not respiratory 

6 sensitization.

7 4.0 Summary 

8

9 In the absence of adequate human data, the IDLH value is based on animal data. Although lethality data are 

10 available (see Table 4), the preferred data that serve as the basis of the IDLH value indicate respiratory 

11 depression, which is categorized as an escape-impairing effect. Kirkpatrick [2003] reported a 30-minute RD50

12 value in mice exposed to 340 ppm. This effect is classified as potentially escape impairing. No duration 

13 adjustment was needed. Application of a composite uncertainty factor of 3 to account for extrapolation from a 

14 threshold for escape-impairing effects in animals, animal to human differences, and human variability yielded an 

15 IDLH value of 113 ppm. 
 External Review Draft 

March 2015 

8

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 5.0 References 

2

3 ACGIH (American Conference of Governmental Industrial Hygienists) [2014]. Annual TLVs® (Threshold Limit 

4 Values) and BEIs® (Biological Exposure Indices) booklet. Cincinnati, OH: ACGIH Signature Publications. 

5

6 AIHA (American Industrial Hygiene Association) [1989]. Odor thresholds for chemicals with established 

7 occupational health standards. Fairfax, VA: American Industrial Hygiene Association, p. 14. 

8

9 AIHA [2006]. AIHA Emergency Response Planning (ERP) Committee procedures and responsibilities. Fairfax, 

10 VA: American Industrial Hygiene Association. [https://www.aiha.org/get11 involved/AIHAGuidelineFoundation/EmergencyResponsePlanningGuidelines/Documents/ERP-SOPs2006.pdf]. 

12 Date accessed: March 17, 2014. 

13

14 AIHA (American Industrial Hygiene Association) [2009]. AIHA Emergency Response Planning (ERP) 

15 Committee procedures and responsibilities. Fairfax, VA: American Industrial Hygiene Association. 

16

17 AIHA (American Industrial Hygiene Association) [2010]. Emergency response planning guidelines (ERPG) and 

18 workplace environmental exposure levels (WEEL) handbook. Fairfax, VA: American Industrial Hygiene 

19 Association Press. 

20

21 AIHA [2010a]. AIHA Emergency Response Planning (ERP) Committee procedures and responsibilities. Fairfax, 

22 VA: American Industrial Hygiene Association. 

23

24 AIHA [2010b]. Emergency response planning guidelines (ERPG) and workplace environmental exposure levels 

25 (WEEL) handbook. Fairfax, VA: American Industrial Hygiene Association Press 

26

27 BASF [1979a]. Unpublished studies (78/623). Ludwigshafen, Germany: BASF. 

28

29 BASF [1979b]. Bericht über die bestimmung der akuten inhalationstoxizität LC50 von n-butylacrylat bie 

30 4stüdiger exposition an Sprague-Dawley-ratten (gefüttert). Ludwigshafen, Germany: BASF. 

31

32 BASF [1979c]. Bericht über die bestimmung der akuten inhalationstoxizität LC50 von n-butylacrylat bie 

33 4stüdiger exposition an Sprague-Dawley-ratten (nüchtern). Ludwigshafen, Germany: BASF. 

34

35 BASF [1980]. Bestimmung der akuten inhalationstoxizität LC50 von butylacrylat als dampf bie 4stüdiger 

36 exposition an Sprague-Dawley-ratten. Ludwigshafen, Germany: BASF. 

37

38 BIBRA [1991]. Toxicity profile n-butyl acrylate. Surrey, UK: BIBRA International, Ltd. 

39

40 Engelhardt G, Klimisch H-J [1983]. n-Butyl acrylate: cytogenetic investigation in the bone marrow of Chinese 

41 hamsters and rats after 4-day inhalation. Fundam Appl Toxicol 3:640–641. 

42

43 HSDB (Hazardous Substances Data Bank) [2014]. [http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB]. Date 

44 accessed: March 17, 2014. 

45

46 IFA (Institut für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung) [2014]. GESTIS: database on 

47 hazardous substances. 
 External Review Draft 

March 2015 

9

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1 [http://gestis-en.itrust.de/nxt/gateway.dll?f=templates&fn=default.htm&vid=gestiseng:sdbeng]. Date accessed: 

2 March 17, 2014. 

3

4

5 Kirkpatrick DT [2003]. Airway irritation/respiratory depression (RD50) study of butyl acrylate in albino mice. 

6 Ashland, OH: WIL Research Laboratories, Inc. Study No. WIL-496001. p. 74. 

7

8 NAS (National Academy of Science) [2001]. Standing operating procedures for developing Acute Exposure 

9 Guidelines Levels for hazardous chemicals. NAS, National Research Council (NRC), Committee on Toxicology, 

10 Subcommittee on Acute Exposure Guideline Levels. National Academy Press: Washington, DC. IBSN: 0-309-

11 07553-X. [http://www.epa.gov/oppt/aegl/pubs/sop.pdf]. Date accessed: March 17, 2014. 

12

13 NAS (National Academies of Science) [2007]. Acute Exposure Guideline Levels (AEGLs) for selected airborne 

14 chemicals. Butyl acrylate (CAS Reg. No. 141-32-2). NAS, National Research Council, Committee on 

15 Toxicology, Subcommittee on Acute Exposure Guideline Levels National Academy Press: Washington, DC. 

16 [http://www.epa.gov/oppt/aegl/pubs/rest118.htm]. Data accessed: August 1, 2014. 

17

18 NIOSH [2004]. NIOSH respirator selection logic. Cincinnati, OH: U.S. Department of Health and Human 

19 Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 

20 DHHS (NIOSH) Publication No. 2005-100. [http://www.cdc.gov/niosh/docs/2005-100/pdfs/2005-100.pdf]. Date 

21 accessed: March 17, 2014. 

22

23 NIOSH [2013]. NIOSH Current Intelligence Bulletin 66: Derivation of Immediately Dangerous to Life or Health 

24 (IDLH) Values. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control 

25 and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2014-

26 100. 

27 [http://www.cdc.gov/niosh/docs/2014-100/pdfs/2014-100.pdf]. Date accessed: March 17, 2014. 

28

29 NIOSH [2014]. NIOSH pocket guide to chemical hazards. Cincinnati, OH: U.S. Department of Health and 

30 Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and 

31 Health, DHHS (NIOSH) Publication No. 2005-149. [http://www.cdc.gov/niosh/npg/]. Date accessed: March 17, 

32 2014. 

33

34 NLM (National Library of Medicine) [2014]. ChemIDplus lite [http://chem.sis.nlm.nih.gov/chemidplus/]. Date 

35 accessed: August 1, 2014. 

36

37 Oberly R, Tansy MF [1985]. LC50 values for rats acutely exposed to vapors of acrylic and methacrylic acid 

38 esters. J Toxicol Environ Health 16:811–822. 

39

40 OSHA (Occupational Safety and Health Administration) [2014]. Occupational Safety and Health Standards. 29 

41 CFR 1910. Subpart Z -- Toxic and Hazardous Substances. OSHA; Washington, DC 

42 [http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9992]. Date accessed: 

43 August 1, 2014. 
 External Review Draft 

March 2015 

10

This information is distributed solely for the purpose of pre-dissemination peer review under applicable 

information quality guidelines. It has not been formally disseminated by the National Institute for Occupational 

Safety and Health. It does not represent and should not be construed to represent any agency determination or 

policy. 

1

2 ten Berge WF, Zwart A, Appelman LM [1986]. Concentration-time mortality response relationship of irritant and 

3 systematically acting vapours and gases. J Haz Mat 13:301–309. 

4

5 Tucek M, Tenglerová J, Kvasnicková M, Maxa K, Mohyluk I, Svandová E, Topolcan O, Vlasák Z, Cikrt M 

6 [2002]. Effect of acrylate chemistry on human health. Int Arch Occup Environ Health 75(Suppl):S67–S72. 

7

8 USEPA (U.S. Environmental Protection Agency) [2014]. Integrated Risk Information System (IRIS). 

9 [http://www.epa.gov/IRIS/]. Date accessed: March 17, 2014.