Concentrations of potentially harmful chemical compounds in dust collected from air filtration systems on the International Space Station (ISS) exceed those found in floor dust from many American homes, a new study reveals.

In the first study of its kind, scientists analyzed a sample of dust from air filters within the ISS and found levels of organic contaminants which were higher than the median values found in US and Western European homes.

Publishing their results in Environmental Science & Technology Letters, researchers from the University of Birmingham, UK, as well as the NASA Glenn Research Center, U.S., say their findings could guide the design and construction of future spacecraft.

Contaminants found in the "space dust" included polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), "novel" brominated flame retardants (BFRs), organophosphate esters (OPEs), polycyclic aromatic hydrocarbons (PAH), perfluoroalkyl substances (PFAS), and polychlorinated biphenyls (PCBs).

BFRs and OPEs are used in many countries to meet fire safety regulations in consumer and commercial applications like electrical and electronic equipment, building insulation, furniture fabrics and foams.

PAH are present in hydrocarbon fuels and emitted from combustion processes, PCBs were used in building and window sealants and in electrical equipment as dielectric fluids, while PFAS have been used in applications like stain proofing agents for fabrics and clothing.