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Propylene imine

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

CAS number: 75–55–8

NIOSH REL: 2 ppm (5 mg/m3) TWA [skin]; NIOSH considers propylene imine to be a potential occupational carcinogen as defined by the OSHA carcinogen policy [29 CFR 1990].

Current OSHA PEL: 2 ppm (5 mg/m3) TWA [skin]

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 2 ppm (4.7 mg/m3) TWA [skin], A2

Description of substance: Colorless, oily liquid with an ammonia-like odor.

LEL: . Unknown

Original (SCP) IDLH: 500 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statements by Patty [1963] that 5 of 6 rats died from a 4-hour exposure to 500 ppm and 3 of 5 guinea pigs died from a 2-hour exposure to 500 ppm; at 500 ppm, rats survived a 2-hour exposure, and guinea pigs survived a 30-minute exposure [Carpenter et al. 1948].

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derived value
RatG. pig

G. pig

G. pig


Carpenter et al. 1949Carpenter et al. 1948

Carpenter et al. 1948

Carpenter et al. 1948

Carpenter et al. 1948

—–LC17 : 500

LC60 : 500

LC100: 500

LC83 : 500





4 hr1 hr

2 hr

4 hr

4 hr

1,000 ppm (2.0)625 ppm (1.25)

800 ppm (1.6)

1,000 ppm (2.0)

1,000 ppm (2.0)

100 ppm63 ppm

80 ppm

100 ppm

100 ppm

Other animal data: It has been reported that rats survived a 2-hour exposure to 500 ppm and guinea pigs survived a 30-minute exposure to 500 ppm [Carpenter et al. 1948].

Human data: None relevant for use in determining the revised IDLH.

Revised IDLH: 100 ppmBasis for revised IDLH: The revised IDLH for propylene imine is 100 ppm based on acute inhalation toxicity data in animals [Carpenter et al. 1948, 1949]. [Note: NIOSH recommends as part of its carcinogen policy that the “most protective” respirators be worn for propylene imine at concentrations above 2 ppm.]


1. Carpenter CP, Smyth HF Jr, Pozzani UC [1949]. The assay of acute vapor toxicity, and the grading and interpretation of results on 96 chemical compounds. J Ind Hyg Toxicol 31:343-346.

2. Carpenter CP, Smyth HF Jr, Shaffer CB [1948]. The acute toxicity of ethylene imine to small animals. J Ind Hyg Toxicol 30:2-6.

3. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 2175.