Direct contact between dust and HBCD-treated fabrics is an important pathway of source-to-dust transfer

Hexabromocyclododecanes (HBCDs) are a class of brominated flame retardant that have found extensive application in consumer products used widely in indoor environments. Although uncertainty remains about the human health impacts of HBCDs, ingestion of HBCD-contaminated indoor dust has been shown to be a particularly significant exposure pathway for young children. Despite this, understanding of the mechanisms via which HBCD transfer from products to indoor dust remains incomplete. In this study, an in-house test chamber was used to investigate transfer of HBCDs from a treated textile sample to indoor dust via direct textile:dust contact. Results were compared with previous data using the same test chamber to examine other pathways via which HBCDs transfer from products to dust, and highlighted HBCD transfer via direct source:dust contact as being particularly important. This novel finding was corroborated by complementary experiments that examined HBCD transfer via direct contact, from other treated textiles to three major components of indoor dust: artificial indoor dust, soil particles, and cotton linters.