2-Hexanone

CAS number: 591–78–6

NIOSH REL: 1 ppm (4 mg/m³) TWA

Current OSHA PEL: 100 ppm (410 mg/m³) TWA

1989 OSHA PEL: 5 ppm (20 mg/m³) TWA

1993-1994 ACGIH TLV: 5 ppm (20 mg/m³) TWA

Description of Substance: Colorless liquid with an acetone-like odor.

LEL:. . Unknown

Original (SCP) IDLH: 5,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statements by AIHA [1968] that guinea pigs exposed to 6,000 ppm showed signs of beginning narcosis at 30 minutes and deep anesthesia at the end of 1 hour; death did not occur for 6.5 hours at this concentration [Specht et al. 1940]. Also, AIHA [1968] reported that 8,000 ppm killed all rats during a 4-hour exposure [Smyth et al. 1954]. [Note: For "convenience", an IDLH of 5,000 ppm (50 × the OSHA PEL) was originally chosen rather than 6,000 ppm.]

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 G. pig Rat	NPIRI 1974 Schrenk et al. 1936 Smyth et al. 1954	8,000 ----- LC100: 8,000	----- 20,000 -----	4 hr 70 min 4 hr	16,000 ppm (2.0) 26,600 ppm (1.33) 16,000 ppm (2.0)	1,600 ppm 2,600 ppm 1,600 ppm

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
G. pig Rat Mouse	Schrenk et al. 1936 Smyth et al. 1954 Tanii et al. 1936	oral oral oral	2,590 ----- 2,430	----- 914 -----	4,358 ppm 1,538 ppm 4,089 ppm	436 ppm 154 ppm 409 ppm

Other animal data: Narcosis occurs in guinea pigs after 30 minutes of exposure to 20,000 ppm [Schrenk et al. 1936].

Human data: Volunteers exposed to 1,000 ppm reported a strong odor and transient, moderate eye and nasal irritation [DiVencenzo et al. 1978].

Revised IDLH: 1,600 ppm Basis for revised IDLH: The revised IDLH for 2-hexanone is 1,600 ppm based on acute inhalation toxicity data in humans [DiVencenzo et al. 1978] and animals [NPIRI 1974; Smyth et al. 1954]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 1,000 ppm.

REFERENCES:

1. AIHA [1968]. 2-Hexanone. In: Hygienic guide series. Am Ind Hyg Assoc J 29:618-620.

2. DiVencenzo GD, Hamilton ML, Kaplan CJ, et al. [1978]. Studies on the respiratory uptake and excretion and the skin absorption of methyl n-butyl ketone in humans and dogs. Toxicol Appl Pharmacol 44:593-604.

3. NPIRI [1974]. Raw materials data handbook, physical and chemical properties, fire hazard and health hazard data. Vol. 1. Organic solvents. Bethlehem, PA: National Printing Ink Research Institute, p. 78.

4. Schrenk HH, Yant WP, Patty FA [1936]. Acute response of guinea pigs to vapors of some noncommercial organic compounds. X. Hexanone (methyl butyl ketone). Public Health Rep 51:624-631.

5. 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.

6. Specht H, Miller JW, Valaer PJ, Sayers RR [1940]. Acute response of guinea pigs to the inhalation of ketone vapors. Washington, DC: U.S. Government Printing Office, Federal Security Agency, U.S. Public Health Service, National Institute of Health Bulletin No, 176, pp. 1-66.

7. Tanii H, Tsuji H, Hashimoto K [1936]. Structure-toxicity relationship of monoketones. Toxicol Lett 30:13-17.