Isobutyl alcohol

CAS number: 78–83–1

NIOSH REL: 50 ppm (150 mg/m³) TWA

Current OSHA PEL: 100 ppm (300 mg/m³) TWA

1989 OSHA PEL: 50 ppm (150 mg/m³) TWA

1993-1994 ACGIH TLV: 50 ppm (152 mg/m³) TWA

Description of substance: Colorless, oily liquid with a sweet, musty odor.

LEL(@123°F): 1.7% (10% LEL(@123°F), 1,700 ppm)

Original (SCP) IDLH: 8,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty [1963] that 2 of 6 rats died when exposed for 4 hours to 8,000 ppm [Smyth et al. 1954].

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal concentration data:

Species	Reference	LC50 (ppm)	LCLo (ppm)	Time	Adjusted 0.5-hr LC (CF)	Derived value
Rat	Smyth et al. 1954	LC33: 8,000	-----	4 hr	16,000 ppm (2.0)	1,600 ppm

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rabbit Rat	Munch and Schwartze 1925 Smyth et al. 1954	oral oral	----- -----	3,750 2,460	8,522 ppm 5,591 ppm	852 ppm 559 ppm

Other animal data: RD₅₀ (mouse), 1,818 ppm [DeCeaurriz et al. 1981].

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

Revised IDLH: 1,600 ppm Basis for revised IDLH: The revised IDLH for isobutyl alcohol is 1,600 ppm based on acute inhalation toxicity data in animals [Smyth et al. 1954]. This may be a conservative value due to the lack of relevant acute toxicity data for workers.

REFERENCES:

1. DeCeaurriz JC, Micillino JC, Bonnet P, Guenier JP [1981]. Sensory irritation caused by various industrial airborne chemicals. Toxicol Lett 9(2):137-143.

2. Munch JC, Schwartze EW [1925]. Narcotic and toxic potency of aliphatic alcohols upon rabbits. J Lab Clin Med 10:985-995.

3. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1448.

4. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC [1954]. Range-finding toxicity data: list V. AMA Arch Ind Hyg Occup Med 10:61-68.