Tetramethyl lead (as Pb)

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

ACUTE TOXICITY DATA:

Lethal concentration data:

Species	Reference	LC50	LCLo	Time	Adjusted 0.5-hr LC (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
Rabbit G. pig Rat	Akatsuka 1973 Gekkan Yakuji 1980 Magistretti et al. 1963	oral oral oral	----- 109 105	24 ----- -----	130 mg Pb/m3 591 mg Pb/m3 570 mg Pb/m3	13 mg Pb/m3 59 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

REFERENCES:

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).