Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 8003–34–7
NIOSH REL: 5 mg/m3 TWA
Current OSHA PEL: 5 mg/m3 TWA
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 5 mg/m3 TWA
Description of substance: Brown, viscous oil or solid.
LEL :. . Unknown
Original (SCP) IDLH: 5,000 mg/m3
Basis for original (SCP) IDLH: The chosen IDLH has been estimated from the rat oral LD50 of 820 mg/kg [Carpenter et al. 1950 cited by ACGIH 1971]. In addition, ACGIH  reported that rats experienced moderate lung congestion when exposed for 30 minutes to 6,000 mg/m3 pyrethrum in peanut oil [Carpenter et al. 1950].
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA:
Lethal dose data:
|Adjusted LD||Derived value|
|Rat||Carpenter et al. 1950||oral||820||-----||5,740 mg/m3||574 mg/m3|
|Rat||Hayes 1982||oral||200-1,870||-----||1,400-13,090 mg/m3||140-1,309 mg/m3|
|Rat||Malone & Brown 1968||oral||273- 796||-----||1,911- 5,572 mg/m3||191- 557 mg/m3|
|Mouse||Miyamoto 1976||oral||370||-----||2,590 mg/m3||259 mg/m3|
|G. pig||Shimkin & Anderson 1936||oral||-----||1,000||7,000 mg/m3||700 mg/m3|
Other animal data: It has been reported that rats experienced moderate lung congestion when exposed for 30 minutes to 6,000 mg/m3 pyrethrum in peanut oil [Carpenter et al. 1950].
Human data: It has been estimated that the fatal human dose might be between 1 and 2 g/kg [Gosselin et al. 1984; Lehman 1949]. [Note: An oral dose of 1 to 2 g/kg is equivalent to a 70-kg worker being exposed to about 47,000 to 93,000 mg/m3 for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]
|Revised IDLH: 5,000 mg/m3 [Unchanged]
Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for pyrethrum. Therefore, based on acute oral toxicity data in humans [Gosselin et al. 1984; Lehman 1949], the original IDLH for pyrethrum (5,000 mg/m3) is not being revised at this time.
1. ACGIH . Pyrethrum. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 219-220.
2. Carpenter CP, Weil CS, Pozzani UC, Smyth HF Jr . Comparative acute and subacute toxicities of allethrin and pyrethrins. AMA Arch Ind Hyg Occup Med 2:420-432.
3. Gosselin RE, Smith HP, Hodge HC . Clinical toxicology of commercial products. 5th ed. Section III. Therapeutics Index. Baltimore, MD: Williams & Wilkins Company, pp. 352-355.
4. Hayes WJ Jr . Pesticides studied in man. Baltimore, MD: Williams & Wilkins Company, pp. 75-80.
5. Lehman AJ . Pharmacological considerations of insecticides. Q Bulletin Assoc Food Drug Off U.S. 13(2):65-70.
6. Malone JC, Brown NC . Toxicity of various grades of pyrethrum to laboratory animals. Pyrethrum Post 9:3-8.
7. Miyamoto J . Degradation, metabolism and toxicity of synthetic pyrethroids. Environ Health Perspect 14:15-28.
8. Shimkin MB, Anderson HH . Acute toxicities of rotenone and mixed pyrethrins in mammals. Proc Soc Exp Biol Med 34:135-138.