Inhalation lethality

Inhalation lethality data are available for several laboratory species, including dogs, rats, mice, and hamsters. Most of the available data, however, were collected using 1,1-dimethylhydrazine as the test material. Independent studies and reports confirm a steep exposure-response relationship for the dimethyl... 

Fowles, J.R., G.V.Alexeeff, and D.Dodge. 1999. The use of benchmark dose methodology with acute inhalation lethality data. Regul. Toxicol. Pharmacol. 29 262-278. 

Acute inhalation lethality data for the rat, mouse, and rabbit for exposure times of 10 s to 12 h were located. A single inhalation study with the dog did not give an exposure duration. The data are summarized in Table 5-4. Data from studies with nonlethal concentrations are summarized in Table 5-5. Barcroft (1931) reported LC50 values and times to death for eight species of animals, the times to death at a constant concentration. Due to experimental design constraints, the LC50 values are not reported here, but relevant data are discussed in the section on relative species sensitivity (Section 4.4.1). 

Takahashi, H., Yoshida, M., Murao, N., and Maita, K. Different inhalation lethality between micron-sized and submicron-sized aerosols of organophosphorus insecticide, chlorfenvinphos, in rats, Toxicol Lett., 73(2) 103-111, 1994. 

Lethal Concentration Amount of toxic substance in air which will likely cause death if inhaled. Lethal Dosage (1) Amount of a toxic substance which is likely to cause death when ingested. (2) Dose of ionizing radiation sufficient to cause death media lethal dose (MLD or LD50) is amount required to kill within a specified period of time (usually 30 days) half of the organisms exposed die LD50/30 for people is about 400-450 roentgens. 

TABLE 6.3. Acute inhalation lethality (LC50 LCtso) for nerve agent vapor in laboratory animals... 

Wilhehnsen, C.L., Pitt, M.L. (1996). Lesions of acute inhaled lethal ricin intoxication in rhesus monkeys. Vet. Pathol. 33 296-302. 

Ocular exposure to vapor causes miosis, conjunctival hyperemia, and eye pain within one to several minutes. Signs can last 2 to 3 days. Liquid tabun penetrates the eye quickly and can result in death nearly as rapidly as an inhalational lethal dose (1 to 10 min) (EPA, 1985c). Ingestion of the liquid causes muscarinic, nicotinic, and CNS signs about 30 min after mild exposures. The signs can last several hours up to 2 to 5 days depending on the amount of exposure. 

Toxic effects on animals from inhalation exposure include anesthetic effects and decreased blood pressure. The 4h inhalation lethal concentration 50% in rats is 164 000 ppm (16.4%). Cardiac sensitization occurred in dogs exposed to concentrations of 20% or greater. 

The oral LD50 in rodents ranges from 3.2 to 6 g kg with intravenous LD50 in rodents ranging from 5.1 in mice to 5.6 in rats. The dermal lethal dose in rabbits is 6gkg and the inhalation lethal concentration for rats exposed for 6h is 1500 ppm. Fetal malformations and fetotoxicity were induced when laboratory animals were treated by the oral, dermal, and injection routes during pregnancy. 

The acute lethality of methanol is low based on animal testing via oral, dermal, and inhalation routes of exposure. The acute oral lethal dose (LD) observed in rats, rabbits, and monkeys range from 7mgkg (monkey) to 14.4 mg kg (rabbits). Acute dermal LD in rabbits have been reported as 20 mg kg and inhalation lethal concentrations ranged from 31 000 ppm (18 h exposure, rats) to 72 000 ppm (54 h exposure, mice). 

Hazard TLV (vapor) ceiling 50 ppm. Toxic by ingestion and inhalation. Lethal dose reported to be 100 cc. 

A retired Naval commander was found dead at home yesterday after inhaling lethal gas used in trench warfare. 

Estimates of the Acute Inhalation Lethal Toxicity of HCN Vapor after McNamara (1976)... 

Table 4. Estimated acute inhalation lethal toxicity of HCN vapor to humans based on the Moore and Gates (1946) analysis. Calculated for a 70 kg man with a breathing rate of 25 1 min-1 and a detoxification rate for cyanide of 0.017 mg kg-1 min-1...

Table 5. Estimates of the acute human inhalation lethal toxicity of HCN vapor after McNamara (1976). Presented as LCr50 and timed LC50 values...

TABLE 3. Inhalation Lethal Toxicity of DFP Vapor to Several Species ... 

TOXICITY TABLE 9.3 Acute Inhalation Lethality (LC50 LCt5o) for Nerve Agent Vapor 95 in Laboratory Animals ... 

Allometric Modeling of Mammalian Cyanogen Chloride Inhalation Lethality... 

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