National Academies Press: OpenBook

Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20 (2016)

Chapter: Appendix C Derivation of AEGL Values for Selected Chloroformates

« Previous: Appendix B Benchmark Concentration Calculations for Selected Chloroformates
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Appendix C

Derivation of AEGL Values for Selected Chloroformates

Methyl Chloroformate

Derivation of AEGL-1 Values for Methyl Chloroformate

Insufficient data were available on methyl chloroformate to derive AEGL-1 values, so no values are recommended.

Derivation of AEGL-2 Values for Methyl Chloroformate

Insufficient data were available on methyl chloroformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for methyl chloroformate by 3.

Calculations:
10-min AEGL-2: 12 ppm ÷ 3 = 4.0 ppm
30-min AEGL-2: 8.5 ppm ÷ 3 = 2.8 ppm
1-h AEGL-2: 6.7 ppm ÷ 3 = 2.2 ppm
4-h AEGL-2: 4.2 ppm ÷ 3 = 1.4 ppm
8-h AEGL-2: 2.1 ppm ÷ 3 = 0.70 ppm

Derivation of AEGL-3 Values for Methyl Chloroformate

Key study: Hoechst. 1986. Chloroformic Acid Methyl Ester. Inhalation Toxicity in the Flow Through System in Male and Female SPF Wistar Rats. 4-hour LC50. Hollander, H., Weigland, W, Mayer, D., Langer, K.H. Hoechst Pharmaceutical Research Toxicology. Report No. 86.0432. April 11, 1986.
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
Toxicity end point: Lethality threshold in rats (4-h BMCL05 of 42.4 ppm)
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(42.4 ppm)3 × 4 h = 304,900 ppm-h
(42.4 ppm)1 × 4 h = 170 ppm-h
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
10-min AEGL-3: C3 × 0.167 h = 304,900 ppm-h
C3 = 1,825,748 ppm
C = 122 ppm
122 ppm ÷ 10 = 12 ppm
30-min AEGL-3: C3 × 0.5 h = 304,900 ppm-h
C3 = 609,800 ppm
C = 84.8 ppm
84.8 ppm ÷ 10 = 8.5 ppm
1-h AEGL-3: C3 × 1 h = 304,900 ppm-h
C3 = 304,900 ppm
C = 67.3 ppm
67.3 ppm ÷ 10 = 6.7 ppm
4-h AEGL-3: 42.4 ppm ÷ 10 = 4.2 ppm
8-h AEGL-3: C1 × 8 h = 170 ppm-h
C1 = 21.2 ppm
C = 21.2 ppm
21 ppm ÷ 10 = 2.1 ppm

Ethyl Chloroformate

Derivation of AEGL-1 Values for Ethyl Chloroformate

Insufficient data were available on ethyl chloroformate to derive AEGL-1 values, so no values are recommended.

Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×

Derivation of AEGL-2 Values for Ethyl Chloroformate

Insufficient data were available on ethyl chloroformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for ethyl chloroformate by 3.

Calculations:
10-min AEGL-2: 8.8 ppm ÷ 3 = 2.9 ppm
30-min AEGL-2: 6.1 ppm ÷ 3 = 2.0 ppm
1-h AEGL-2: 4.8 ppm ÷ 3 = 1.6 ppm
4-h AEGL-2: 1.2 ppm ÷ 3 = 0.40 ppm
8-h AEGL-2: 0.60 ppm ÷ 3 = 0.20 ppm

Derivation of AEGL-3 Values for Ethyl Chloroformate

Key study: Vernot, E.H., J.D. MacEwen, C.C. Haun, and E.R. Kinkead. 1977. Acute toxicity and skin corrosion data for some organic and inorganic compounds and aqueous solutions. Toxicol. Appl. Pharmacol. 42:417-424.
Toxicity end point: Lethality threshold; estimated LC01 (LC50 ÷ 3) from a 1-h exposure in male rats.
LC50 = 145 ppm; 145 ppm ÷ 3 = 48.3 ppm (point of departure)
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(48.3 ppm)3 × 1 h = 112,769 ppm-h
(48.3 ppm)1 × 1 h = 48.3 ppm-h
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
10-min AEGL-3: C3 × 0.167 h = 112,769 ppm-h
C3 = 675,263 ppm
C = 87.7 ppm
87.7 ppm ÷ 10 = 8.8 ppm
30-min AEGL-3: C3 × 0.5 h = 112,769 ppm-h
C3 = 225,538 ppm
C = 60.9 ppm
60.9 ppm ÷ 10 = 6.1 ppm
1-h AEGL-3: 48.3 ppm ÷ 10 = 4.8 ppm
4-h AEGL-3: C1 × 4 h = 48.3 ppm-h
C1 = 12 ppm
C = 12 ppm
12 ppm ÷ 10 = 1.2 ppm
8-h AEGL-3: C1 × 8 h = 48.3 ppm-h
C1 = 6.0 ppm
C = 6.0 ppm
6.0 ppm ÷ 10 = 0.60 ppm

Isopropyl Chloroformate

Derivation of AEGL-1 Values for Isopropyl Chloroformate

Insufficient data were available on isopropyl chloroformate to derive AEGL-1 values, so no values are recommended.

Derivation of AEGL-2 Values for Isopropyl Chloroformate

Insufficient data were available on isopropyl chloroformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for isopropyl chloroformate by 3.

Calculations:
10-min AEGL-2: 11 ppm ÷ 3 = 3.7 ppm
30-min AEGL-2: 11 ppm ÷ 3 = 3.7 ppm
1-h AEGL-2: 9.1 ppm ÷ 3 = 3.0 ppm
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
4-h AEGL-2: 5.7 ppm ÷ 3 = 1.9 ppm
8-h AEGL-2: 3.8 ppm ÷ 3 = 1.3 ppm

Derivation of AEGL-3 Values for Isopropyl Chloroformate

Key study: Collins, C.J., and B.G. Proctor. 1984. A 5-day Range-Finding Inhalation Toxicity Study of Isopropyl Chloroformate in the Albino Rat. Draft Report. Prepared by Bio-Research Laboratories, Ltd.: Quebec, Canada. Prepared for PPG Industries, Pittsburgh, PA.
Toxicity end point: Concentration causing no mortality in male and female rats exposed for 6 h/day for 5 days (50 ppm)
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(50 ppm)3 × 6 h = 750,000 ppm-h
(50 ppm)1 × 6 h = 300 ppm-h
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
10-min AEGL-3: 11 ppm (set equal to 30-min AEGL-3 value, because of the uncertainty associated with extrapolating a 6-h point-of-departure to a 10-min value)
30-min AEGL-3: C3 × 0.5 h = 750,000 ppm-h
C3 = 1,500,000 ppm
C = 114 ppm
114 ppm ÷ 10 = 11 ppm
1-h AEGL-3: C3 × 1 h = 750,000 ppm-h
C3 = 750,000 ppm
C = 90.9 ppm
90.9 ppm ÷ 10 = 9.1 ppm
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
4-h AEGL-3: C3 × 4 h = 750,000 ppm-h
C3 = 187,500 ppm
C = 57.2 ppm
57.2 ppm ÷ 10 = 5.7 ppm
8-h AEGL-3: C1 × 8 h = 300 ppm-h
C1 = 37.5 ppm
37.5 ppm ÷ 10 = 3.8 ppm

n-Propyl Chloroformate

Derivation of AEGL-1 Values for n-Propyl Chloroformate

Insufficient data were available on propyl chloroformate to derive AEGL-1 values, so no values are recommended.

Derivation of AEGL-2 Values for n-Propyl Chloroformate

AEGL-2 values for propyl chloroformate were set equal to AEGL-2 values for isopropyl chloroformate, because of the inadequate data on propyl chloroformate and the similar toxicity of the two chemicals.

Calculations:
10-min AEGL-2: 3.7 ppm
30-min AEGL-2: 3.7 ppm
1-h AEGL-2: 3.0 ppm
4-h AEGL-2: 1.9 ppm
8-h AEGL-2: 1.3 ppm

Derivation of AEGL-3 Values for n-Propyl Chloroformate

AEGL-3 values for n-propyl chloroformate were set equal to AEGL-3 values for isopropyl chloroformate, because of the inadequate data on n-propyl chloroformate and the similar toxicity of the two chemicals.

Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
Calculations:
10-min AEGL-3: 11 ppm
30-min AEGL-3: 11 ppm
1-h AEGL-3: 9.1 ppm
4-h AEGL-3: 5.7 ppm
8-h AEGL-3: 3.8 ppm

Allyl Chloroformate

Derivation of AEGL-1 Values for Allyl Chloroformate

Insufficient data were available on allyl chloroformate to derive AEGL-1 values, so no values are recommended.

Derivation of AEGL-2 Values for Allyl Chloroformate

Insufficient data were available on allyl chloroformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for allyl chloroformate by 3.

Calculations:
10-min AEGL-2: 3.8 ppm ÷ 3 = 1.3 ppm
30-min AEGL-2: 2.6 ppm ÷ 3 = 0.87 ppm
1-h AEGL-2: 2.1 ppm ÷ 3 = 0.70 ppm
4-h AEGL-2: 0.53 ppm ÷ 3 = 0.18 ppm
8-h AEGL-2: 0.26 ppm ÷ 3 = 0.09 ppm

Derivation of AEGL-3 Values for Allyl Chloroformate

Key study: Stillmeadow Inc. 1987. Rat Acute Inhalation Toxicity: Allyl Chloroformate. Stillmeadow, Inc. Biological Testing Laboratory: Houston, TX. Project No. 4438-86. Report Submitted to PPG
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
Industries, Inc.: Chicago, IL. February 19, 1987. OTS0536028.
Toxicity end point: Lethality threshold (1-h rat BMCL05 = 21 ppm)
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(21 ppm)3 × 1 h = 9,261 ppm-h
(21 ppm)1 × 1 h = 21 ppm-h
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
10-min AEGL-3: C3 × 0.167 h = 9,261 ppm-h
C3 = 55,455 ppm
C = 38 ppm
38 ppm ÷ 10 = 3.8 ppm
30-min AEGL-3: C3 × 0.5 h = 9,261 ppm-h
C3 = 18,522 ppm
C = 26.4 ppm
26.4 ppm ÷ 10 = 2.6 ppm
1-h AEGL-3: 21 ppm ÷ 10 = 2.1 ppm
4-h AEGL-3: C1 × 4 h = 21 ppm-h
C1 = 5.25 ppm
C = 5.25 ppm
5.25 ppm ÷ 10 = 0.53 ppm
8-h AEGL-3: C1 × 8 h = 21 ppm-h
C1 = 2.63 ppm
C = 2.63 ppm
2.63 ppm ÷ 10 = 0.26 ppm

n-Butyl Chloroformate, Isobutyl
Chloroformate, and sec-Butyl Chloroformate

Data were insufficient to derive AEGL values for isobutyl or sec-butyl chloroformate. Because these two compounds are structural analogs of n-butyl

Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×

chloroformate and because they appear to have similar toxicity, the AEGL values for n-butyl chloroformate were adopted for these chemicals. The section below shows how the values for n-butyl chloroformate were derived.

Derivation of AEGL-1 Values for n-Butyl Chloroformate

Insufficient data were available on n-butyl chloroformate to derive AEGL-1 values, so no values are recommended. No values are also recommended for isobutyl chloroformate or sec-butyl chloroformate.

Derivation of AEGL-2 Values for n-Butyl Chloroformate

Insufficient data were available on n-butyl chloroformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for n-butyl chloroformate by 3. The values were also applied to isobutyl chloroformate and sec-butyl chloroformate.

Calculations:
10-min AEGL-2: 12 ppm ÷ 3 = 4.0 ppm
30-min AEGL-2: 8.4 ppm ÷ 3 = 2.8 ppm
1-h AEGL-2: 6.7 ppm ÷ 3 = 2.2 ppm
4-h AEGL-2: 1.7 ppm ÷ 3 = 0.57 ppm
8-h AEGL-2: 0.83 ppm ÷ 3 = 0.28 ppm

Derivation of AEGL-3 Values for n-Butyl Chloroformate

Key study: BASF. 1970. BASF AG,
Gewerbehygienisch-Pharmakologisches Institut. n-Butylchlorokohlensaureester-Gewerbetoxikologische Vorprufung. Unpublished Report No. XIX 352
Toxicity end point: Estimated 1-h lethality threshold in rats (66.7 ppm) 4/10 rats died after exposure at 200 ppm for 1 h; lethality threshold was estimated by taking one-third of that concentration (200 ppm ÷ 3 = 66.7 ppm).
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(66.7 ppm)3 × 1 h = 296,741 ppm-h
(66.7 ppm)1 × 1 h = 66.7 ppm-h
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
10-min AEGL-3: C3 × 0.167 h = 296,741 ppm-h
C3 = 1,776,892 ppm
C = 121 ppm
121 ppm ÷ 10 = 12 ppm
30-min AEGL-3: C3 × 0.5 h = 296,741 ppm-h
C3 = 593,482 ppm
C = 84.0 ppm
84.0 ppm ÷ 10 = 8.4 ppm
1-h AEGL-3: 66.7 ppm ÷ 10 = 6.7 ppm
4-h AEGL-3: C1 × 4 h = 66.7 ppm-h
C1 = 16.8 ppm
C = 16.8 ppm
16.8 ppm ÷ 10 = 1.7 ppm
8-h AEGL-3: C1 × 8 h = 66.7 ppm-h
C1 = 8.34 ppm
C = 8.34 ppm
8.34 ppm ÷ 10 = 0.83 ppm

AEGL-3 values for n-butyl chloroformate were also applied to isobutyl chloroformate and sec-butyl chloroformate.

Benzyl Chloroformate

Derivation of AEGL-1 Values for Benzyl Chloroformate

Insufficient data were available on benzyl chloroformate to derive AEGL-1 values, so no values are recommended.

Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×

Derivation of AEGL-2 Values for Benzyl Chloroformate

Insufficient data were available on benzyl chloroformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for benzyl chloroformate by 3.

Calculations:
10-min AEGL-2: 3.7 ppm ÷ 3 = 1.2 ppm
30-min AEGL-2: 3.7 ppm ÷ 3 = 1.2 ppm
1-h AEGL-2: 2.9 ppm ÷ 3 = 0.97 ppm
4-h AEGL-2: 1.9 ppm ÷ 3 = 0.63 ppm
8-h AEGL-2: 0.93 ppm ÷ 3 = 0.31 ppm

Derivation of AEGL-3 Values for Benzyl Chloroformate

Key study: BASF. 1990. Study on the Acute Inhalation Toxicity LC50 of Benzyl Chloroformate as a Vapor in Rats, 4-Hour Exposure. Project No. 13I0674/887075. Unpublished report, BASF Aktiengesellschaft, Experimental Toxicology and Ecology: Ludwigshafen, Germany.
February 15, 1990.
Toxicity end point: Concentration causing no mortality in 4-h rat study (18.6 ppm)
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(18.6 ppm)3 × 4 h = 25,739 ppm-h
(18.6 ppm)1 × 4 h = 74.4 ppm-h
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
10-min AEGL-3: 3.7 ppm (set equal to 30-min AEGL-3 value, because of the uncertainty associated with extrapolating a 4-h point-of-departure to a 10-min value)
30-min AEGL-3: C3 × 0.5 h = 25,739 ppm-h
C3 = 51,478 ppm
C = 37.2 ppm
37.2 ppm ÷ 10 = 3.7 ppm
1-h AEGL-3: C3 × 1 h = 25,739 ppm-h
C3 = 25,739 ppm
C = 29.5 ppm
29 ppm ÷ 10 = 2.9 ppm
4-h AEGL-3: 18.6 ppm ÷ 10 = 1.9 ppm
8-h AEGL-3: C1 × 8 h = 74.4 ppm-h
C1 = 9.3 ppm
C = 9.3 ppm
9.3 ppm ÷ 10 = 0.93 ppm

Phenyl Chloroformate

Derivation of AEGL-1 Values for Phenyl Chloroformate

Insufficient data were available on phenyl chloroformate to derive AEGL-1 values, so no values are recommended.

Derivation of AEGL-2 Values for Phenyl Chloroformate

Insufficient data were available on phenyl chloroformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for phenyl chloroformate by 3.

Calculations:
10-min AEGL-2: 0.72 ppm ÷ 3 = 0.24 ppm
30-min AEGL-2: 0.72 ppm ÷ 3 = 0.24 ppm
1-h AEGL-2: 0.57 ppm ÷ 3 = 0.19 ppm
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
4-h AEGL-2: 0.36 ppm ÷ 3 = 0.12 ppm
8-h AEGL-2: 0.18 ppm ÷ 3 = 0.06 ppm

Derivation of AEGL-3 Values for Phenyl Chloroformate

Key studies: BASF. 1990. Study on the Acute Inhalation Toxicity LC50 of Phenyl Chloroformate as a Vapor in Rats, 4-Hour Exposure. Project No. 13I0675/887076. Unpublished report, BASF Aktiengesellschaft, Experimental Toxicology and Ecology: Ludwigshafen, Germany. January 18, 1990.
Hoechst. 1989. Chloroformic Acid Phenyl Ester. Aerosol Inhalation Toxicity in Male and Female SPF Wistar Rats. 4-Hour LC50. Hofmann, T. Hoechst Pharmaceutical Research Toxicology. Report No. 89.0761. April 26, 1989.
Toxicity end point: Lethality threshold (4-h rat BMCL05 = 3.6 ppm)
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(3.6 ppm)3 × 4 h = 186.7 ppm-h
(3.6 ppm)1 × 4 h = 14.4 ppm-h
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
10-min AEGL-3: 0.72 ppm (set equal to 30-min AEGL-3 value, because of the uncertainty associated with extrapolating a 4-h point-of-departure to a 10-min value)
30-min AEGL-3: C3 × 0.5 h = 186.7 ppm-h
C3 = 373.4 ppm
C = 7.2 ppm
7.2 ppm ÷ 10 = 0.72 ppm
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
1-h AEGL-3: C3 × 1 h = 186.7 ppm-h
C3 = 186.7 ppm
C = 5.7 ppm
5.7 ppm ÷ 10 = 0.57 ppm
4-h AEGL-3: 3.6 ppm ÷ 10 = 0.36 ppm
8-h AEGL-3: C1 × 8 h = 14.4 ppm-h
C1 = 1.8 ppm
C = 1.8 ppm
1.8 ppm ÷ 10 = 0.18 ppm

2-Ethylhexyl Chloroformate

Derivation of AEGL-1 Values for 2-Ethylhexyl Chloroformate

Insufficient data were available on 2-ethylhexyl chloroformate to derive AEGL-1 values, so no values are recommended.

Derivation of AEGL-2 Values for 2-Ethylhexyl Chloroformate

Insufficient data were available on 2-ethylhexyl chloroformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for 2-ethylhexyl chloroformate by 3.

Calculations:
10-min AEGL-2: 3.6 ppm ÷ 3 = 1.2 ppm
30-min AEGL-2: 3.6 ppm ÷ 3 = 1.2 ppm
1-h AEGL-2: 2.9 ppm ÷ 3 = 0.97 ppm
4-h AEGL-2: 1.8 ppm ÷ 3 = 0.60 ppm
8-h AEGL-2: 0.91 ppm ÷ 3 = 0.30 ppm

Derivation of AEGL-3 Values for 2-Ethylhexyl Chloroformate

Key study: BASF. 1985. Acute Inhalation Toxicity LC50 for a 4-Hour Exposure (Rats), Vapor Test of 2-Ethylhexyl Chloroformate. Unpublished report, BASF Aktiengesellschaft, Experimental Toxicology
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
and Ecology: Ludwigshafen, Germany. February 8, 1985.
Toxicity end point: Lethality threshold (4-h rat BMCL05 [18.1 ppm])
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(18.1 ppm)3 × 4 h = 23,719 ppm-h
(18.1 ppm)1 × 4 h = 72.4 ppm-h
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
10-min AEGL-3: 3.6 ppm (set equal to 30-min AEGL-3 value, because of the uncertainty associated with extrapolating a 4-h point-of-departure to a 10-min value)
30-min AEGL-3: C3 × 0.5 h = 23,719 ppm-h
C3 = 47,438 ppm
C = 36.2 ppm
36.2 ppm ÷ 10 = 3.6 ppm
1-h AEGL-3: C3 × 1 h = 23,719 ppm-h
C3 = 23,719 ppm
C = 28.7 ppm
28.7 ppm ÷ 10 = 2.9 ppm
4-h AEGL-3: 18.6 ppm ÷ 10 = 1.8 ppm
8-h AEGL-3: C1 × 8 h = 72.4 ppm-h
C1 = 9.1 ppm
C = 9.1 ppm
9.1 ppm ÷ 10 = 0.91 ppm
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×

Ethyl Chlorothioformate

Derivation of AEGL-1 Values for Ethyl Chlorothioformate

Insufficient data were available on ethyl chlorothioformate to derive AEGL-1 values, so no values are recommended.

Derivation of AEGL-2 Values for Ethyl Chlorothioformate

Insufficient data were available on ethyl chlorothioformate to derive AEGL-2 values. In the absence of relevant data, AEGL-2 values were estimated by dividing the AEGL-3 values for ethyl chlorothioformate by 3.

Calculations:
10-min AEGL-2: 3.0 ppm ÷ 3 = 1.0 ppm
30-min AEGL-2: 3.0 ppm ÷ 3 = 1.0 ppm
1-h AEGL-2: 2.4 ppm ÷ 3 = 0.80 ppm
4-h AEGL-2: 1.5 ppm ÷ 3 = 0.50 ppm
8-h AEGL-2: 0.75 ppm ÷ 3 = 0.25 ppm

Derivation of AEGL-3 Values for Ethyl Chlorothioformate

Key study: Stauffer Chemical Company. 1983. Acute Inhalation Toxicity of Ethyl Chlorothioformate in Rats (T-10710). Environmental Health Center Inhalation Facility. Stauffer Chemical Company: Farmington, CT. OTS0538464.
Toxicity end point: Estimated 4-h lethality threshold of 15 ppm in rats (LC50 = 45 ppm; 45 ppm ÷ 3)
Time scaling: Cn × t = k; default values of n = 3 for extrapolating to shorter durations and n = 1 for extrapolating to longer durations (NRC 2001).
(15 ppm)3 × 4 h = 13,500 ppm-h
(15 ppm)1 × 4 h = 60 ppm-h
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
×
Uncertainty factors: 3 for interspecies differences
3 for intraspecies variability
Calculations: Point of departure ÷ product of the uncertainty factors
10-min AEGL-3: 3.0 ppm (set equal to 30-min AEGL-3 value, because of the uncertainty associated with extrapolating a 4-h point-of-departure to a 10-min value)
30-min AEGL-3: C3 × 0.5 h = 13,500 ppm-h
C3 = 27,000 ppm
C = 30 ppm
30 ppm ÷ 10 = 3.0 ppm
1-h AEGL-3: C3 × 1 h = 13,500 ppm-h
C3 = 13,500 ppm
C = 23.8 ppm
23.8 ppm ÷ 10 = 2.4 ppm
4-h AEGL-3: 15 ppm ÷ 10 = 1.5 ppm
8-h AEGL-3: C1 × 8 h = 60 ppm-h
C1 = 7.5 ppm
C = 7.5 ppm
7.5 ÷ 10 = 0.75 ppm
Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Suggested Citation:"Appendix C Derivation of AEGL Values for Selected Chloroformates." National Academies of Sciences, Engineering, and Medicine. 2016. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20. Washington, DC: The National Academies Press. doi: 10.17226/23634.
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Next: Appendix D Acute Exposure Guideline Levels for Selected Chloroformates »
Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 20 Get This Book
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Extremely hazardous substances can be released accidentally as a result of chemical spills, industrial explosions, fires, or accidents involving railroad cars and trucks transporting EHSs. Workers and residents in communities surrounding industrial facilities where these substances are manufactured, used, or stored and in communities along the nation's railways and highways are potentially at risk of being exposed to airborne EHSs during accidental releases or intentional releases by terrorists. Pursuant to the Superfund Amendments and Reauthorization Act of 1986, the U.S. Environmental Protection Agency (EPA) has identified approximately 400 EHSs on the basis of acute lethality data in rodents.

Acute Exposure Guideline Levels for Selected Airborne Chemicals, Volume 20 reviews and updates the technical support document on acute exposure guideline levels (AEGLs) for selected chloroformates. This update focuses on establishing AEGL-3 values for n-propyl chloroformate and isopropyl chloroformate, but will also consider whether any new data are available that would affect the proposed values for the other 10 chloroformates.

AEGLs represent threshold exposure limits (exposure levels below which adverse health effects are not likely to occur) for the general public and are applicable to emergency exposures ranging from 10 minutes (min) to 8 h. Three levels - AEGL-1, AEGL-2, and AEGL-3 - are developed for each of five exposure periods (10 min, 30 min, 1 h, 4 h, and 8 h) and are distinguished by varying degrees of severity of toxic effects. This report will inform planning, response, and prevention in the community, the workplace, transportation, the military, and the remediation of Superfund sites.

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