o-Toluidine

CAS number: 95–53–4

NIOSH REL: None established; NIOSH considers o-toluidine to be a potential occupational carcinogen as defined by the OSHA carcinogen policy [29 CFR 1990] that may be absorbed through the skin.

Current OSHA PEL: 5 ppm (22 mg/m3) TWA [skin]

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 2 ppm (8.8 mg/m3) TWA [skin], A2

Description of substance: Colorless to pale-yellow liquid with an aromatic, aniline-like odor.

LEL: . . Unknown

Original (SCP) IDLH: 100 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Sax [1975] that 100 ppm is the maximum concentration endurable for 1 hour without serious consequences. No other data are available on which to base the IDLH.

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rat Mouse Rabbit Rat Rat	IARC 1982 IARC 1982 IARC 1982 Jacobsen 1972 Jacobsen 1972	oral oral oral oral oral	670 520 840 900 940	----- ----- ----- ----- -----	1,052 ppm 816 ppm 1,318 ppm 1,413 ppm 1,475 ppm	105 ppm 82 ppm 132 ppm 141 ppm 148 ppm

Other animal data: Rats have survived an 8-hour exposure to saturated vapors of o-toluidine [Smyth et al. 1962].

Human data: It has been reported that a 60-minute exposure to 40 ppm produces severe toxic effects [Goldblatt 1955]. It has been reported that 100 ppm is the maximum concentration endurable for 1 hour without serious consequences [Sax 1975].

Revised IDLH: 50 ppm Basis for revised IDLH: The revised IDLH for o-toluidine is 50 ppm based on acute inhalation toxicity data in humans [Goldblatt 1955; Sax 1975]. [Note: NIOSH recommends as part of its carcinogen policy that the "most protective" respirators be worn for o-toluidine at any detectable concentration.]

REFERENCES:

1. Goldblatt MW [1955]. Research in industrial health in the chemical industry. Brit J Ind Med 12:1-20.

2. IARC [1982]. ortho-Toluidine and its hydrochloride. In: IARC monographs on the evaluation of carcinogenic risk of chemicals to humans. Vol. 27. Some aromatic amines, anthraquinones and nitroso compounds, and inorganic fluorides used in drinking-water and dental preparations, pp. 155-175.

3. Jacobsen KH [1972]. Short communication: acute oral toxicity of mono- and di-alkyl ring-substituted derivatives of aniline. Toxicol Appl Pharmacol 22:153-154.

4. Sax NI [1975]. o-Toluidine. In: Dangerous properties of industrial materials. 4th ed. New York, NY: Van Nostrand Reinhold Company, pp. 1173-1176.

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