The acute toxicity of many brominated flame retardants is lower than that of salt.
- time:
- 2019-05-13
In recent years, more and more stringent restrictions have been made on the use of flame retardants in terms of safety and environmental protection, which has led to many misunderstandings of some flame retardants and attracted great attention of the industry.
It is understood that the relevant fire protection laws and standards of many countries in the world have mandatory requirements that the corresponding plastic parts in electronic classifications, buildings and vehicles "must" meet the requirements of flame retardant and fire prevention, that is to say, flame retardant must be added. But are flame retardants, especially brominated flame retardants, harmful to human health and the environment? What is the restriction clause of the United Nations Stockholm Convention on Brominated Flame Retardants? Many people don't really understand.
Brominated flame retardants are applicable to almost all materials requiring flame retardancy. At present, only hexabromocyclododecane is banned in Stockholm Convention. Most brominated flame retardants have been strictly evaluated and proved harmless to human body and environment.
According to the Secretary-General of the China Society for Flame Retardant, most brominated flame retardants do not carry toxic labels, and many brominated flame retardants are even less acute toxic than salt, such as tetrabromobisphenol A, which is a brominated flame retardant with ** dosage.
With the development of economy and the improvement of people's living standard, the hidden danger of fire accidents has become increasingly prominent in our country. Fire safety has become an important issue in the national economic and social life. Adding flame retardants to flammable materials has become an important means of controlling fire occurrence from the source. The Chinese Fire Retardant Society reminds the public and society that it is necessary to correctly understand the important role of bromine flame retardants in controlling fire occurrence at the source and avoid generalizing them.
According to the assessment of the European Commission, the use of flame retardants has reduced fire deaths in Europe by 20% in the past 10 years. Fire tests conducted by the National Bureau of Standards (NIST) on five categories of products also showed that people who stayed in rooms with flame retardant materials had an average escape time of 15 times longer than those who stayed in rooms without flame retardant materials.
Brominated flame retardants are a kind of important flame retardants. They are widely used in flame retardant materials because they can directly interfere with the chain reaction of combustion. China's RoHS, Regulations on Pollution Control and Management of Electronic Information Products, restricts the use of PBBs and PBDEs rather than brominated flame retardants as a whole.
According to reports, the contaminant team of the European Food Safety Agency (EFSA) food chain has made a large number of assessments of possible brominated flame retardants in food in the past two years and concluded that most of the assessed brominated flame retardants do not have health risks and their presence in food is unlikely to cause concern. This includes polybrominated biphenyls, polybrominated diphenyl ethers, hexabromocyclododecane and tetrabromobisphenol A.
Relevant experts said that the normal use and recovery of brominated flame retardants did not increase the emission of toxic and harmful gases in the air. Dioxins can be formed only when individual brominated flame retardants are burned under certain conditions, such as incomplete combustion. Large-scale incineration experiments of plastic waste in Europe have proved that the dioxins and furans produced by co-combustion are not directly related to the bromine content of waste. The combustion of any substance releases a variety of toxic and harmful gases such as carbon monoxide. The National Bureau of Standards has tested a series of products containing or without flame retardants. The total amount of toxic gas released by flame retardant products is 1/3 less than that of non-flame retardant products, carbon monoxide emissions are about half less, and smoke production is roughly the same.
In addition, for other flame retardants, bromine flame retardants show better recyclability and stability. Plastics containing bromine flame retardants can maintain the same mechanical properties and fire grade as the original materials after recycling. Studies in Japan, the United States and Europe have shown that the mechanical and flame retardant properties of plastics containing brominated flame retardants are maintained after repeated recycling. "In 2010, Panasonic Electrical Appliances used red phosphorus flame retardant instead of bromine flame retardant in its refrigerator products to meet halogen-free requirements. As a result, 360,000 refrigerators had to be recalled and bromine flame retardant was re-used in the replacement parts.
The development of new brominated flame retardants has never been interrupted. At present, a new type of polymeric (macromolecule) brominated flame retardant has been successfully developed to replace hexabromocyclododecane. The flame retardant is more environmentally friendly because its molecular size is too large to penetrate biological cell membranes to participate in body circulation and metabolism, so it can not harm organisms.
