BFRs and PFAS Flashcards
What is flame retardant?
a substance added or a treatment applied to a material to suppress, or significantly reduce or delay the combustion of material
What are the two most abundant chemicals in flame retardants?
Aluminum thrihydroxide and halogenated flame retardant
What is the most reactive halogenalkanes?
c-f
What are the three sub groups of BFRs?
tetrabromobisphenol A (TBBPA)
Hexabromocyclododecane (HBCD)
Polybrominated diphenyl ethers (PBDEs)
What are the legacy BFRs?
HBCD and PBDEs
What are the properties of TBBPA?
reactive 80% & additive 20%-primary use in electronics and circuit boards
What are the properties of HBCD?
only additive, used in electronics, textile backings, thermal insulation in buildings
What are the properties of of PBDEs?
Additive, used in cushions, sofas, electronics and other consumer products
What are the general properties of BFRs?
as molecular weight increases, volatility and water solubility decrease while organic carbon binding increases
What are the ways to get exposed to BFRs?
Inhalation, food, waste streams (electronic waste), household wastes (gets into water), breast milk
What are the three major food sources of BFRs?
fish oil supplements, poultry liver and poultry fat
What are the indoor routes of exposure to BFRs?
dust and childrens toys
What is concerning about dust being a major route of exposure?
plays major role in exposure to infants, toddlers and children
Where is the highest level of BFR exposure to humans in the world and why?
Southeast Asia and other under developed parts of the world because the e-waste is imported illegally there
What are the target organs of the BFRs?
liver, thyroid and endocrine
How do BFRs effect the liver?
Increased phase 1 and 2 enzymes, increased liver weight and histopathological changes
How do BFRs interact with the thyroid?
hydroxylated PBDEs look like T4 and have a greater binding affinity for transthyretin binding protein
WHat are the effects of PBDEs on developing fetuses?
fetuses do not make their own T4 until the second trimester, and rely on the mother as a source of T4 which is delivered by TTR, increase in hyperactivity and lower IQ
What are novel brominated flame retardants?
derivatives of known BFRs
What are the physio-chemical properties of the novel BFRs?
as molecular weight increases, water solubility, and volatility decrease as binding for organic compounds increase
What are the toxic effects of novel BFRs?
carcinogenic, endocrine disruptor, some bioaccumulative and very toxic to aquatic life
What are polyfluroalkyl substances?
man made chemicals resistant to heat, water and oil
What are the two subcategories of PFAS?
perfluorooctanoic acid and perfluorooctanesulfonic acid
What is the half life of PFAS?
> 40 years
