Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)
CAS number: 75–31–0
NIOSH REL: The 1989 OSHA PEL may not be protective to workers.
Current OSHA PEL: 5 ppm (12 mg/m3) TWA
1989 OSHA PEL: 5 ppm (12 mg/m3) TWA, 10 ppm (24 mg/m3) STEL
1993-1994 ACGIH TLV: 5 ppm (12 mg/m3) TWA, 10 ppm (24 mg/m3) STEL
Description of substance: Colorless liquid with an ammonia-like odor.
LEL: . . Unknown
Original (SCP) IDLH: 4,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by ACGIH  that 0 of 6 rats died from a 4-hour exposure to 4,000 ppm and 6 of 6 rats died after a 4-hour exposure to 8,000 ppm [Smyth et al. 1951]. No other quantitative data are available on which to base the IDLH.
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA:
Lethal concentration data:
|Rat||NCI 1974||4,000||-----||4 hr||8,000 ppm (2.0)||800 ppm|
|Mouse||Shell 1961||-----||7,000||40 min||7,630 ppm (1.09)||763 ppm|
|Rat||Smyth et al. 1951||LC100: 8,000||-----||4 hr||16,000 ppm (2.0)||1,600 ppm|
Other animal data: It has been reported that rats have survived an exposure to 4,000 ppm for 4 hours [Smyth et al. 1951].
Human data: Volunteers have complained of nose and throat
irritation after brief exposures to concentrations ranging from
10 to 20 ppm [Amoore and Hautala 1983].
|Revised IDLH: 750 ppm
Basis for revised IDLH: The revised IDLH for isopropylamine is 750 ppm based on acute inhalation toxicity data in animals [NCI 1974; Shell 1961]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 20 ppm.
1. ACGIH . Isopropylamine. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 141-142.
2. Amoore JE, Hautala E . Odor as an aid to chemical safety: odor threshold compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution. J Appl Toxicol 3(6):272-290.
3. NCI . Memorandum (June 17, 1974). Interagency Collaborative Group on Environmental Carcinogenesis, National Cancer Institute.
4. Shell . Unpublished report. New York, NY: Shell Chemical Corporation, p. 7.
5. Smyth HF Jr, Carpenter CP, Weil CS . Range-finding toxicity data: list IV. AMA Arch Ind Hyg Occup Med 4:119-122.
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