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

CAS number: 98–01–1

NIOSH REL: The 1989 OSHA PEL may not be protective to workers.

Current OSHA PEL: 5 ppm (20 mg/m3) TWA [skin]

1989 OSHA PEL: 2 ppm (8 mg/m3) TWA [skin]

1993-1994 ACGIH TLV: 2 ppm (7.9 mg/m3) TWA [skin]

Description of Substance: Colorless to amber liquid with an almond-like odor.

LEL: . . 2.1% (10% LEL, 2,100 ppm)

Original (SCP) IDLH: 250 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement that 260 ppm was the lethal concentration for rats, but caused no deaths in mice or rabbits [Quaker Oats cited by AIHA 1965].

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derivedvalue




Deichmann and Gerarde 1969Deichmann and Gerarde 1969

Quaker Oats

Terrill et al. 1989

Terrill et al. 1989









6 hr6 hr


6 hr

1 hr

851 ppm (2.3)851 ppm (2.3)


403 ppm (2.3)

1,296 ppm (1.25)

85 ppm85 ppm


40 ppm

130 ppm


Other animal data: It has been stated that 260 ppm (duration of exposure undefined) caused no deaths in mice or rabbits [Quaker].

Human data: Widespread eye and respiratory tract irritation has been noted in workers exposed to concentrations ranging from 5 to 16 ppm [Apol and Lucas 1975]. Headaches, itching of the throat, and red and weeping eyes have occurred at concentrations ranging from 1.9 to 14 ppm [Korenman and Resnik 1930].



1. AIHA [1965]. Furfural. In: Hygienic guide series. Am Ind Hyg Assoc J 26:196-199.

2. Apol AG, Lucas JB [1975]. Health hazard evaluation, Pacific Grinding Wheel Co., Maysville, WA. Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, NIOSH Report No. HHE 73-18-171, NTIS No. 246-444.

3. Deichmann WB, Gerarde HW [1969]. Furfural (2-furaldehyde; pyromucic aldehyde; artificial oil of ants). In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., pp. 279-280.

4. Korenman IM, Resnik IB [1930]. Furfural as an industrial poison and its determination in the air. Arch Hyg 104:344-357 (in German). [From ACGIH [1991]. Furfural. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 694-695.]

5. Quaker Oats [?]. Physiological data on QO furfural. Chicago, IL: Quaker Oats Company, Chemicals Division. [From AIHA [1965]. Furfural. In: Hygienic guide series. Am Ind Hyg Assoc J 26:196-199.]

6. Terrill JB, Van Horn WE, Robinson D, Thomas DL [1989]. Acute inhalation toxicity of furan, 2-methyl furan, furfuryl alcohol, and furfural in the rat. Am Ind Hyg Assoc J 50:A359-A361.

Page last reviewed: December 4, 2014