Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 78–30–8
NIOSH REL: 0.1 mg/m3 TWA [skin]
Current OSHA PEL: 0.1 mg/m3 TWA
1989 OSHA PEL: 0.1 mg/m3 TWA [skin]
1993-1994 ACGIH TLV: 0.1 mg/m3 TWA [skin]
Description of substance: Colorless to pale-yellow, odorless liquid or solid (below 52°F).
LEL: . . Unknown
Original (SCP) IDLH: 40 mg/m3
Basis for original (SCP) IDLH: No data on acute inhalation toxicity are available on which to base an IDLH for triorthocresyl phosphate. The chosen IDLH has been estimated from oral toxicity data cited by ACGIH . ACGIH  reported that serious paralysis has been produced in man by an oral dose of the order of 6 to 7 mg/kg [Patty 1963].
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA:
Lethal dose data:
|Adjusted LD||Derived value|
|Mouse||Bleiberg &Johnson 1965||oral||900||-----||6,300 mg/m3||630 mg/m3|
|Rabbit||Gross & Grosse 1932||oral||-----||100||700 mg/m3||70 mg/m3|
|Rat||Veronesi et al. 1984||oral||1,160||-----||8,120 mg/m3||812 mg/m3|
Human data: It has been reported that serious paralysis has been produced by an oral dose of about 6.6 mg/kg [Deichmann and Gerarde 1969] and that the probable lethal dose is greater than 28 mg/kg [Patty 1963]. [Note: Oral doses of 6.5 or 28 mg/kg are equivalent to a 70-kg worker being exposed to about 300 or 1,300 mg/m3, respectively, for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]
|Revised IDLH: 40 mg/m3 [Unchanged]
Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for triorthocresyl phosphate. However, based on acute oral toxicity data in humans [Deichmann and Gerarde 1969; Patty 1963], the original IDLH for triorthocresyl phosphate (40 mg/m3) is not being revised at this time.
1. ACGIH . Triorthocresyl phosphate. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 271-272.
2. Bleiberg MJ, Johnson H . Effects of certain metabolically active drugs and oximes on tri-o-cresyl phosphate toxicity. Toxicol Appl Pharmacol 7:227-235.
3. Deichmann WB, Gerarde HW . Tricresyl phosphates. In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., Inc., p. 604.
4. Gross E, Grosse A . A contribution on the toxicology of ortho-tri-cresyl-phosphates. Arch Exp Pathol Pharmakol 168:473-514 (in German).
5. Patty FA, ed. . Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1920.
6. Veronesi B, Newland D, Inman A . The effect of metabolic interference on rodent-sensitivity to tri-ortho-cresyl phosphate (TOCP). Toxicologist 4:55 [Abstract].