Harmful Chemicals in Sealants and Caulks

This chart of harmful chemicals in sealants and caulks more fully lists specific chemicals, which sealants they may be found in and potential hazards. The chart is in order from most to least problematic toxin. There also are links from the chemical names to data sheets that detail both the acute—or short-term—effects and those that are long term or chronic. Definitions of the top hazards also can be found by clicking on those listings.

Warning Level* Type of Sealant Chemical Purpose Top Hazards  (Hover Mouse for Description)
Purple - very high concern MS Polyether 2, 4 di tert-butyl-6-(5-chlorobenzotriazole-2-yl)phenol UV stabilizer Bioaccumulation toxin
Purple - very high concern Silicone Decamethylcyclopentasiloxane Intermediate for silicone copolymers Bioaccumulation toxin; Developmental hazards
Purple - very high concern MS Polyether Dibutyltin bis (acetylacetonate) Catalyst Bioaccumulation toxin
Purple - very high concern Silicone Dibutyltin dilaurate Catalyst Bioaccumulation toxin; Developmental hazards
Purple - very high concern Silicone Octamethylcyclotetrasiloxane Intermediate for silicone copolymers Bioaccumulation toxin
Purple - very high concern Spray Polyurethane Foam Tris (1-chloro-2-propyl)phosphate (TCPP) Fire protection Bioaccumulation toxin; Reproductive harm
Red - High Concern Silicone 2,4,5-trichlorophenoxyacetic acid By-product of curing process Reproductive harm; Developmental hazards
Red - High Concern Silicone Petroleum Distillates Hydrotreated Middle Solvent Cancer
Red - High Concern Acrylic Latex; MS Polyether; Polyurethane Phthalates Plasticizer Reproductive harm; Asthma
Red - High Concern Acrylic Latex; MS Polyether; Butyl Quartz/Silica Filler Cancer
Red - High Concern Silicone Siloxanes and Silicones Building block of silicone Bioaccumulation toxin
Red - High Concern Acrylic Latex; Butyl; Polyurethane Stoddard Solvent Solvent Cancer; Reproductive harm
Red - High Concern Polyurethane; Spray Polyurethane Foam TDI Building block of polyurethane Cancer; Asthma
Red - High Concern Polyurethane; Butyl; Acrylic Latex; Silicone; MS Polyether Titanium Dioxide Pigment, Filler Cancer
Red - High Concern Silicone Toluene Solvent Developmental hazards; Reproductive harm
Red - High Concern Polyurethane Xylene Solvent Reproductive harm; Developmental hazards
Orange - medium concern Acrylic Latex Ammonium Hydroxide pH Adjuster Asthma
Orange - medium concern Polyurethane; Spray Polyurethane Foam MDI Building block of polyurethane Cancer; Asthma
Orange - medium concern Silicone Methyl ethyl ketone Solvent Developmental hazards; Developmental hazards