SIRC commissioned Sciences International (SI) of Alexandria, Virginia, to perform a screening-level risk assessment to determine the potential health impact of children’s indoor exposure associated with styrene. This unpublished report addressed exposure associated with styrenic-based toys, other styrenic-based materials found indoors, in food, and in indoor air. SI reviewed available literature on styrene monomer migration from plastic materials, children’s mouthing behavior, styrene naturally occurring in food, and styrene measurements in indoor air. They considered the following exposure pathways: (a) ingestion of styrene from mouthing of toys, (b) ingestion of styrene from mouthing of other styrenic-based objects, (c) ingestion of styrene in food due to migration from food-contact articles, (d) ingestion of naturally occurring styrene in food, and (e) inhalation of styrene in indoor air. Additionally, SI conducted an aggregate assessment combining all of these pathways to consider the total styrene ingestion exposure. The conclusion of this conservative, screening-level risk assessment was that styrene monomer exposures to children are very low and are well below levels of public health concern.
Styrene Occurrence in Food
Styrene is detectable in many foods in their natural state.
SIRC sponsored a study to determine amounts of styrene found in common foods obtained directly from the farm, or site of import (i.e., with no potential for exposure to processing, packaging, or preparation materials). The study showed that concentrations of styrene were present in eight of twelve selected food types, including cinnamon, beef, coffee beans, peanuts, wheat, oats, strawberries, and peaches (Steele et al. 1994). [Insert footnote] The results indicate styrene may be a component of many foods at their source, and that the occurrence of styrene in processed foods cannot be assumed to be related to the use of styrene-based packaging, storage containers, or preparation materials.