EPS Insulation (expanded polystyrene)
This information reflects our best understanding of product composition in 2019.
ASTM C578 defines expanded polystyrene (EPS) thermal insulation as a, "cellular plastic product manufactured from pre-expanded polystyrene beads subsequently molded into desired shapes and sizes resulting in a product which is rigid with...
ASTM C578 defines expanded polystyrene (EPS) thermal insulation as a, "cellular plastic product manufactured from pre-expanded polystyrene beads subsequently molded into desired shapes and sizes resulting in a product which is rigid with closed cellular structure." EPS foams fall into ASTM C578 Types I, II, VIII, IX, XI, XIV, and XV. Rigid EPS foam boards contain flame retardants, blowing agents, and some processing additives. This CP describes unfaced, rigid EPS foam insulation boards suitable for a range of insulating applications. Specialty boards may contain additional additives or facing materials. Potential additives include graphite, found in graphite polystyrene insulation (GPS), and insecticides for termite resistance which may be needed for certain applications in regions where termite infestation is “very heavy” according to building code. Insecticides, including disodium octaborate tetrahydrate and imidicloprid, add additional hazards. Some EPS insulation may contain pre-consumer recycled content at up to 10-20%.
In comments to the EPA in 2017, the industry association (EPS Industry Alliance) stated that their member resin manufacturers have completely transitioned away from the use of HBCD (a persistent, bioaccumulative, toxicant) as a flame retardant, typically in favor of the flame retardant listed here. These manufacturers supply resin for an estimated 80-85% of the EPS insulation manufactured in the United States. It is not clear whether any of the other 15-20% still contains HBCD.
A historical version of this CP is available here: https://www.pharosproject.net/material/show/2180347.