Campus Essay: Science-based Understanding of Eco-friendly Flame Retardants
8th July 2021
China Campus Essay Call on Science-based Understanding of Flame Retardants was launched in November 2020 and concluded in May2021 and its organized by The China Association of Flame Retardant Materials (CAFRM), China Flame Retardant Society (CFRS) and International Bromine Council (BSEF). The jury, formed by Prof. Zhou Zhengmao and Prof. Hao Jianwei of Beijing Institute of Technology, made assessment of all the 21 entries and selected one 1st prize winning essay and three 2nd prize winning essays.
The 1st prize goes to Ms. Wang Wenwen and Ms. Yang Lijie from Beijing University Chemical Technology with their essay named “Science-based Understanding of Eco-friendly Flame Retardants”. This is the second campus essay call on the theme of science-based understanding of flame retardants in China, while the first one took place in 2015.
|Ms. Yang Lijie Ms. Wang Wenwen|
Essay: “Science-based Understanding of Eco-friendly Flame Retardants”
With the wide application of polymer materials and electronic consumer products, both fire risks and hazards are increasing, highlighting the importance of flame retardancy, in which flame retardants play an indispensable role. In the future, flame retardants will be greener, more efficient and environmental- friendly.
Flame retardants can improve the flame resistance of molecular materials by increasing the ignition point or reducing the burning rate of materials so as to increase rescue time, save lives and cut losses. Flame retardants can be classified into halogenated flame retardants and halogen-free flame retardants. Most flame retardant materials in the field of daily life and transportation, are halogenated flame retardants, because they are extremely cost-efficient. Only a small amount can achieve the required flame resistance. As additive flame retardants, halogenated flame retardants have good compatibility with polymer materials and cause no affect to their physical and chemical properties. Halogen-free flame retardants include phosphorus-based flame retardants, intumescent flame retardants, inorganic flame retardants, silicon-containing flame retardants, and bio-based flame retardants. Most halogen-free flame retardants contain phosphorus and nitrogen。
A misunderstanding that halogen-free flame retardants are environmental-friendly flame retardants has been existing for a long time out of four reasons. First, the adverse effects of individual halogenated flame retardants is over-generalized to the whole halogenated flame retardants; second, some research results about the halogenated flame retardants are misinterpreted; third, due to the difficulty of detecting the structure of compounds exceeds the difficulty of detecting elements, people only judge the halogen element for convenience; fourth, some individuals, companies and research institutes advertise such viewpoint for profit-making purposes, forcing downstream manufacturers to abandon the use of all halogen-containing flame retardants in order to carry out blue ocean marketing and so on. In fact, some halogen-free flame retardants, such as most phosphate esters, some phosphates, and hypophosphites, contain hazardous substances. Therefore, there is no scientific basis for judging whether a chemical is eco-friendly by a certain chemical element it contains!
As a kind of chemical, flame retardant needs to meet three conditions to achieve environmental friendliness.
- from the perspective of the chemical structure, it should be environmental non-PBT and non-toxic and harmless to the human body. Specifically, environmental non-PBT refers to chemicals that have little impact on persistent pollution, bio-accumulation, mobility, and eco-toxicity, and are non-toxic to humans and have no impact on human health.
- the entire life cycle has little impact on the environment, which is mainly reflected in the low carbon footprint, environmental release and comprehensive energy consumption during the entire process from production, manufacturing, transportation, use to disposal. In addition, the waste should be properly treated or recyclable.
- the flame retardant product has necessary physical and chemical properties and use performance. Moreover, it can meet the regulatory requirements of relevant laws and regulations. Only all these three conditions are met can flame retardants meet the green chemistry and take an environmental-friendly development.