Appendices 1-18 to: Report on the Health Effects of Selected Pesticide Coformulants

Appendices 1-18 to: Report on the Health Effects of Selected Pesticide Coformulants

142 Evaluation

The toxicology database available on HMP is limited, with a number of elder studies being summarily described.

HMP is the major metabolite of methylisobutylketone. It appears to be absorbed following inhalation and oral exposure. No data were available on the metabolism and excretion of HMP.

Data in animals on HMP indicated a low acute toxicity by all three routes of exposure.

In humans, the substance was irritating to eyes, nose and throat at 483 mg/m³. In animals, high concentrations were reported to be irritating to mucous membranes. Though elder data in rabbits indicated severe eye irritation from exposure to HMP, the substance is evaluated to be mildly irritating to the rabbit eyes on the basis of a guideline study. Skin irritation data in rabbits indicated that HMP is a mild to moderate skin irritant. The substance is reported to be defatting to the skin.

No data were available on the sensitising potential of the substance.

A human case of glomerulonephritis caused by mixed exposure to a paint containing HMP and ethanol as solvents has been reported. However, a causal relationship is not possible on the basis of one case of mixed exposure. Prolonged exposure of rats to 4830 mg/m³ is reported to be toxic to the kidney in males, producing changes in the proximal tubules. As the effect is restricted to the male rats, it is considered that this could be due to the accumulation of α₂_m-globulin. This effect is considered not to be relevant to humans.

HMP was negative in bacteria tests and in a yeast mutagenicity assay. A slightly clastogenic but not dose-related effect was seen in a chromosome aberration assay in vitro. No in vivo data on mutagenicity or genotoxicity were found. Overall, the available evidence indicated that the substance is not genotoxic.

No information on toxicity to reproduction or on carcinogenicity was found.

On the basis of the available data, HMP is evaluated to be irritating to the eyes and to the mucous membranes. Other end-points could not be evaluated because of insufficient data.