N,N-Dimethylaniline

CAS number: 121–69–7

NIOSH REL: 5 ppm (25 mg/m³) TWA, 10 ppm (50 mg/m³) STEL [skin]

Current OSHA PEL: 5 ppm (25 mg/m³) TWA [skin]

1989 OSHA PEL: 5 ppm (25 mg/m³) TWA, 10 ppm (50 mg/m³) STEL [skin]

1993-1994 ACGIH TLV: 5 ppm (25 mg/m³) TWA, 10 ppm (50 mg/m³) STEL [skin]

Description of Substance: Pale yellow, oily liquid with an amine-like odor.

LEL:. . Unknown

Original (SCP) IDLH: 100 ppm

Basis for original (SCP) IDLH: No quantitative data on acute inhalation toxicity are available for dimethylaniline. Because the TLV for dimethylaniline is based on an analogy with aniline [ACGIH 1971], the chosen IDLH is also based on an analogy with aniline, which has an IDLH of 100 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	Slusar et al. 1972	-----	50	4 hr	100 ppm (2.0)	10 ppm

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rat	Smyth et al. 1962	oral	1,410	-----	1,958 ppm	196 ppm

Human data: N,N-Dimethylaniline has been reported to be quantitatively less toxic than aniline but produces a very similar effect -- notably, methemoglobinemia [Clayton and Clayton 1981]. It has been reported that 50 mg/kg is the lethal oral dose [Hall 1969]. [Note: An oral dose of 50 mg/kg is equivalent to a 70-kg worker being exposed to 2,333 mg/m³ (463 ppm) for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

Revised IDLH: 100 ppm [Unchanged] Basis for revised IDLH: Based on an analogy with aniline [Clayton and Clayton 1981] which has an IDLH of 100 ppm and to acute oral toxicity data in humans [Hall 1969], the original IDLH for N,N-dimethylaniline (100 ppm) is not being revised for at this time.

REFERENCES:

1. ACGIH [1971]. Dimethylaniline (n-dimethylaniline). In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 89.

2. Clayton GD, Clayton FE, eds. [1981]. Patty's industrial hygiene and toxicology. 3rd rev. ed. Vol. 2A. Toxicology. New York: John Wiley & Sons, Inc., pp. 2416-2454.

3. Hall R [1969]. Adhesives. Washington DC: National Clearinghouse for Poison Control Centers Bulletin, p. 5. Jan/Feb, 1969.

4. Slusar MP, Zvezday VI, Kolodub FA [1972]. Hygienic standardization of N,N-dimethylaniline in the air of industrial premises. Gig Sanit 37(4):35-37 (in Russian).

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.