ABSTRACT
Polyoxymethylene (POM) is a polymer of formaldehyde used inter alia for kitchenware and food processing machines. By migration into food, consumers may be exposed to small additional amounts of formaldehyde in food. In order to address such potential exposures, Specific Migration Limits are derived using all studies with oral exposure in mammals and birds. The assessment is not only based on local irritation observed in a 2-year rat study that has previously served to calculate acceptable exposure levels, but also on systemic effects, namely on effects on the kidney in adult rats and testes in birds before sexual maturity. At the relatively high oral exposure levels (up to 2000â¯ppm in drinking water) long-term effects caused by formic acid, the first step metabolite of formaldehyde, such as acidosis, cannot be excluded. The lowest Specific Migration Limit of 2.74â¯mg/dm2, corresponding to 16.5â¯mg formaldehyde/kg food, is based upon kidney effects in rats, leading to potential exposures that range between 2900 and 4400 times below the endogenous turnover of formaldehyde. Lastly, a recent migration study with POM showed that migration of formaldehyde into food simulants is over an order of magnitude below the lowest Specific Migration Limit derived herein.
Subject(s)
Dietary Exposure/standards , Food Contamination , Formaldehyde/standards , Administration, Oral , Animals , Chickens , Dogs , Formaldehyde/metabolism , Formaldehyde/toxicity , Kidney/drug effects , Leukocyte Count , Male , No-Observed-Adverse-Effect Level , Quail , Rats, Sprague-Dawley , Rats, Wistar , Resins, Synthetic/chemistry , Risk Assessment , Species Specificity , Stomach/drug effects , Testis/drug effectsABSTRACT
Regulation EU 10/2011 requires a risk assessment of Non Intentionally Added Substances (NIAS) migrating into food for food contact plastics within the EU. Styrene oligomers are important potential components of NIAS in polystyrene used for food packaging and so far only dimers and trimers have been identified. They are not genotoxic in vitro, and there is good evidence that they are not endocrine disruptors. Hazard characterization to establish "safe" exposure levels is based on 1. The No Adverse Effect Level (NOAEL) of 1â¯mg/kgâ¯bw/d in an oral rat study during pregnancy and lactation and 2. The concept of Threshold of Toxicological Concern (TTC). Likely human exposure is derived from 1. the concentrations of dimers and trimers in food simulants or 2. in food and 3. the probabilistic FACET exposure estimation based on dimer and trimer concentrations in polystyrene and their potential for migration. The Margin of Safety as the relation of potential consumer exposure and the "safe" exposure level was always above 1 (apart from migration with 95% ethanol which is no longer recommended as an official food simulant for overall migration into fatty food) demonstrating that dimers and trimers in PS food packaging present a low risk for consumers.
