Semester 1 Flashcards
What are BFRs?
Diverse group of chemicals with C-Br bonds. Extensively applied to flame-proof a wide range of building materials and consumer products.
How do BRFs work?
They break the cycle of self propagation
give an extra 9s in a room on fire
Self Propagating heat used to break strong C-Br bond, therefore reduces the production of flammable gases
What does PBDE stand for
Poly Brominated diphenyl ethers
Describe Penta-BDEs
3-6 Br
Poly Urethana
Foams- furniture, cars, cushions
Describe Octa-BDEs
7 Br
Hard Plastics
TVs, monitors, computer casings, electric appliances
Describe Deca-BDEs
10-Br
Same uses as 3-6 and 7 Br
HBCD
2- Hexabromocyclododecane POP • Polystyrene foam for thermal insulation panels • Upholstery fabrics
TBBPA)
Tetrabromobisphenol-A
• Printed circuit boards.
• hard plastic polymers.
Why are we concerned about BFRs
Persistence in soil
Bioaccumulation
potential for long range transport
toxicity- (endocrine disruption, nerotoxcity, genotoxocoty, development toxicity, possible carcinogens)
Regulatory actions for BFRs
PBDEs/HBCDs in POPs list
REACH and RoHs directives
voluntary actions
UNP- Stockholm convention- USA and China not part of
Sources for BFRs in the environment
Release during manufacture PAST
Release during incorporation of plastics PAST
Emissions from consumer products PRESENT
Emissions from waste and waste recycling PRESENT- FURUTE
Define Exposure of a human to a chemical
Contact with a chemical
Conc. in external environment * Extent of contact with external environment
Why measure exposure
Input into RA models predicting potential adverse effects that may arise from exposure to chemicals
How are we exposed?
Diet- Bio-Accumulation
Inhalation
Ingestion- indoor dust
Dermal Contact
Dietary exposure =
conc. in food * daily food intake
