Derivation of EU-Lowest Concentration of Interest (LCI) of propylene glycol monomethyl ether for the health-based assessment of emission levels from construction products

摘要

The health-based evaluation of chemical emissions from construction products is an integral part of the harmonisation framework for indoor products labelling schemes in the EU. One approach within this framework is the establishment of the "lowest concentration of interest" (LCI), which is a health-based reference concentration for inhalation exposure used to assess emissions after 28 days from a single product. These values are applied in product safety assessment with the goal to avoid health risks from long-term exposure of the general population. The EU-LCI derivation involves three main steps: compilation of toxicological data, data evaluation, and EU-LCI derivation. The EU-LCI derivation process for propylene glycol monomethyl ether (PGME, CAS 107-98-2) is presented here as an example. PGME is predominantly used as a solvent in chemical synthesis and manufacturing of paints and coatings with an annual volume in the EU summing up to 100000-1000000 tonnes. PGME exhibits low acute toxicity to experimental animals. It is not a skin sensitiser or irritant and is a mild eye irritant. Effects observed from repeated dose studies include mild central nervous system depression, liver changes and decrease in body weight gain, but they are often observed at the highest tested d oses (e.g. >3000 ppm). There is little evidence to indicate that PGME is a reproductive toxicant, and PGME has not been shown to be genotoxic or carcinogenic. The derivation of the EU-LCI for PGME is based on the chronic 2-year inhalation study conducted in rodents. The increased incidence of eosinophilic foci in the livers of PGME-exposed male rats was considered as the most critical effect, and 300 ppm (no-observed-adverse-effect-concentration/NOAEC for this effect) was set as the point of departure for the derivation. Total assessment factor of 140 for exposure duration and inter-/intraspecies differences was applied, which resulted in a derived EU-LCI value of 7900 ug/m~3.