Ketone solvents MEK, MIBK and 2,4-PD are harmful to human health, according to a draft assessment by the Canadian government.
In addition to many industrial applications, the chemicals are used in consumer products, such as paints, coatings, adhesives, food flavouring agents, cosmetics and biocides.
The draft screening assessment, published on 19 January, concludes that they meet at least one of the criteria of section 64 of the Canadian Environmental Protection Act (Cepa).
If the final assessment, expected in January 2020, confirms the conclusion, the government would be obliged under Cepa to take risk management measures against the chemicals.
Animal studies suggest that MEK (methyl ethyl ketone or 2-butanone) may cause developmental effects. The assessment focused on these for determination of risk values, using exposure scenarios for a range of consumer products. It found that the risk could be too high for consumer use of lacquer remover, adhesive remover, paint thinner, liquid paint or spray paint containing the chemical.
MIBK (methyl isobutyl ketone MIBK or 4-methyl-2-pentanone) has a category 2 carcinogenicity – "possibly carcinogenic to humans" – classification under the International Agency for Research on Cancer’s (Iarc’s) system. Additionally, animal studies suggest that the compound may cause various non-cancer effects, namely liver, kidney and developmental effects. The assessment focused on the non-cancer effects for determination of risk values and found that the risk could be too high for consumer use of wood lacquer, liquid paint or spray paint containing the chemical.
Animal studies suggest that 2,4-PD (2,4-pentanedione) may cause systemic and developmental effects, on which the assessment focused for determination of risk values. The assessment found that the risk could be too high for consumer use of floor coating products containing the chemical.
MEK, MIBK and 2,4-PD were evaluated as part of a group of ten ketones. The draft screening assessment concludes that none of the other seven are harmful at current levels of exposure. Additionally, none of the ten chemicals are harmful to the environment, it says.
Also on 19 Jan, the government published its risk management scope for MEK, MIBK and 2,4-PD and launched a 60-day public consultation on the documents, which ends on 20 March.