Methyl (n-amyl) ketone

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

CAS number: 110–43–0

NIOSH REL: 100 ppm (465 mg/m3) TWA

Current OSHA PEL: 100 ppm (465 mg/m3) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 50 ppm (233 mg/m3) TWA

Description of substance: Colorless to white liquid with a banana-like, fruity odor.

LEL(@151°F): 1.1% (10% LEL(@151°F), 1,100 ppm)

Original (SCP) IDLH: 4,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty [1963] that 2,000 ppm was strongly narcotic and 4,800 ppm caused narcosis and death in guinea pigs in 4 to 8 hours [Specht et al. 1940].

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50




Time Adjusted 0.5-hr


Derived value
Rat Clayton & Clayton 1981 ----- 4,000 4 hr 8,000 ppm (2.0) 800 ppm
G. pig Specht et al. 1940 ----- 2,000 14.8 hr 6,180 ppm (3.09) 618 ppm

Lethal dose data:

Species Reference Route LD50




Adjusted LD Derived value
Rat Smyth et al. 1962 oral 1,670 ----- 2,461 ppm 246 ppm
Mouse Srepel & Akacic 1962 oral 730 ----- 1,076 ppm 108 ppm

Other animal data: Exposures to guinea pigs lasting 4-8 hours were irritating to the mucous membranes at 1,500 ppm, strongly narcotic at 2,000 ppm, and caused narcosis and death at 4,800 ppm [Specht et al. 1940].

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

Revised IDLH: 800 ppm

Basis for revised IDLH: The revised IDLH for methyl (n-amyl) ketone is 800 ppm based on acute inhalation toxicity data in animals [Clayton and Clayton 1981].


1. Clayton GD, Clayton FE, eds. [1981]. Patty’s industrial hygiene and toxicology. 3rd rev. ed. Vol. 2C. Toxicology. New York, NY: John Wiley & Sons, Inc., p. 4757.

2. Patty FA, ed. [1063]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1740.

3. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC, Striegel JA [1962]. Range-finding toxicity data: list VI. Am Ind Hyg Assoc J 23:95-107.

4. Specht H, Miller JW, Valaer PJ, Sayers RR [1940]. Acute response of guinea pigs to the inhalation of ketone vapors. NIH Bulletin 176:1-66.

5. Srepel B, Akacic B [1962]. Ispitivanje anthelminti_kog djelovanja eteri_nih ulja roda Ruta. Acta Pharmaceut Jugo 12:79-86 (in Serbo-Croatian).

Page last reviewed: December 4, 2014