Isobutyl alcohol

IDLH Documentation
CAS number: 78­83­1

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

1993­1994 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].

Short­term 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
RatSmyth 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):137­143.

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

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]. Range­finding toxicity data: list V. AMA Arch Ind Hyg Occup Med 10:61­68.

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