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Tetramethyl lead (as Pb)

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

CAS number: 75–74–1

NIOSH REL: 0.075 mg/m3 TWA [skin]

Current OSHA PEL: 0.075 mg/m3 TWA [skin]

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 0.15 mg/m3 TWA [skin]

Description of substance: Colorless liquid (unless dyed red, orange, or blue) with a fruity odor.

LEL: . . Unknown

Original (SCP) IDLH: 40 mg Pb/m3

Basis for original (SCP) IDLH: The chosen IDLH is based on an analogy with tetraethyl lead which has an IDLH of 40 mg Pb/m3.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50 LCLo Time Adjusted 0.5-hrLC (CF) Derived value
Mouse Castellino et al.1963 40,800 mg/m3 —– 30 min 31,626 mg Pb/m3 (1.0) 3,163 mg Pb/m3
Rat Cremer &Calloway 1961 8,870 mg/m3 —– 30 min 6,876 mg Pb/m3 (1.0) 688 mg Pb/m3
Mouse Marhold 1986 —– 8,500 mg/m3 30 min 6,589 mg Pb/m3 (1.0) 659 mg Pb/m3

Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value
RabbitG. pig


Akatsuka 1973Gekkan Yakuji 1980

Magistretti et al. 1963







130 mg Pb/m3591 mg Pb/m3

570 mg Pb/m3

13 mg Pb/m359 mg Pb/m3

57 mg Pb/m3

Other animal data: It has been reported that signs of acute tetramethyl lead intoxication in rats were similar to that seen after acute poisoning with tetraethyl lead [ACGIH 1991].

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

Revised IDLH: 40 mg Pb/m3 [Unchanged]Basis for revised IDLH: Based on acute inhalation toxicity data in animals [Castellino et al. 1963; Cremer and Calloway 1961; Marhold 1986], a value of 150 mg Pb/m3 (i.e., 2,000 times the NIOSH REL) would have been appropriate for tetramethyl lead. However based on an analogy to tetraethyl lead which has a revised IDLH of 40 mg Pb/m3, the original IDLH for tetramethyl lead (40 mg Pb/m3) is not being revised at this time


1. ACGIH [1991]. Tetramethyl lead. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 1521-1523.

2. Akatsuka K [1973]. Tetraalkyl lead poisoning. Sangyo Igaku (Japanese Journal of Industrial Health) 15:3-66.

3. Castellino N, Rossi A, Mole R [1963]. Miscellanea: toxicity of tetramethyl lead solutions to mice and rabbits. Brit J Ind Med 20:63-65.

4. Cremer JE, Calloway S [1961]. Further studies on the toxicity of some tetra and trialkyl lead compounds. Brit J Ind Med 18:277-282.

5. Gekkan Yakuji (Pharmaceuticals Monthly) [1980]; 22(3):455-459 (in Japanese).

6. Magistretti M, Zurlo N, Scollo F, Pacillo D [1963]. Tossicita comparata del piombo tetra-etile e del piombo tetra-metile. Med Lav 54:486-495 (in Italian).

7. Marhold J [1986]. Prehled Prumyslove Toxikologie, Organicke Latky. Prague, Czechoslovakia: Avicenum, p. 1258 (in Czechoslovakian).