What are Flame Retardants?
Flame Retardants are any chemicals added to manufactured materials such as plastics, textiles and surface coatings, to inhibit, suppress, or delay the production of flames and prevent the spread of fire. They have been used in many consumer and industrial products, since the 1970s, to decrease the ability of materials to ignite. Inorganic and organic flame retardant have been used. There are three primary types of organic frame retardants: bromine (Br), chlorine (Cl) and phosphate (P).
Many flame retardants are persistent organic pollutants POPs, toxic, man-made, hazardous chemical that have dangerous effects on the environment and our health.
Flame Retardants: a succession of regrettable substitutions
Repeatedly, flame retardants are removed from the market and/or their production is stopped when their toxicity to human and the environment is proven and/or they are officially recognized and listed under the Stockholm Convention a global treaty to protect human health and the environment from POPs. However, the need for flame retardants substances – real or perceived – linked to increased safety requirements incorporated in the regulations and standards of the manufacturing industries - means that new chemicals are continuously produced to replace the forbidden ones. This is a classic pattern for POPs of regrettable substitutions: introducing a toxic chemical, ban it after noticing its harmful impacts, then using a new chemical – probably equally toxic but not yet scrutinized and proven as so - to replace it.
Mirex listed in 2004 was one of the first chemical used as flame retardant, followed by other Chlorinated chemicals such as PCB listed in 2004, and PeCB listed in 2009. They were replaced by Brominated chemicals: PBDEs tetraBDE / pentaBDE /hexaBDE / heptaBDE listed in 2009 and decaBDE listed in 2017, HBB listed in 2009, HBCD listed in 2013. The Chlorinated paraffins substituted the brominated chemicals: SCCP was listed in 2017, MCCP is proposed for listing. Fluorinated chemicals were shortly used as flame or fire retardant until recently: PFOS was listed in 2009, PFOA in 2019, PFHxS in 2022. Currently Phosphate chemicals (TDCP, TCEP, TnBP) are increasingly used for the purpose of reducing flammability.
Flame retardants uses and waste
Flame retardants are industrial chemicals that can be found in an array of products in furnishings (foam, upholstery, carpets, curtains), in electronics and electrical devices (computers, phones, household appliances), in transportation (seats, seats covers and fillings, bumpers, overhead compartments and other parts of automobiles, trains and airplanes) and in building construction materials (electrical wires and cables, thermal insulation foams, paint, adhesives and sealants).
The global market for flame retardants is considerable: In 2017 worldwide consumption of flame retardants amounted to more than 2.25 million tonnes per year (source: GCOII). The market value flame retardants worldwide amounted to some 8.39 billion U.S. dollars in 2019. It is forecast that the market size of this industry will grow to around 16.6 billion worldwide in the year 2030 (source: Statistica).
Once discarded, a product containing flame retardants chemicals is still contaminated with the chemicals that can leak into the environment if the waste is not properly managed. Due to the wide array of sectors and products using a variety of additives substances, and the huge quantities of discarded electronics and electrical devices and appliances, the identification and handling of equipment and wastes containing flame retardants is considered a challenge. Flame retardant in waste can be a barrier to circular economy: the presence of a toxic substance may imply that the material cannot be recycled at the end of life or may contaminate other materials that could be recycled or re-used.
What are the hazardous effects of flame retardants chemicals?
Flame retardants listed in the Stockholm Convention have POPs characteristics: they are highly persistent, have a high potential for bioaccumulation and biomagnification, as well as for long-range transport. There is evidence of their toxic effects in wildlife, including mammals. Adverse effects are reported for soil organisms, birds, fish, frog, rat, mice, and humans where they have been linked to cancer, hormone disruption and other adverse health effects.
Adverse reproductive, developmental, behavioural, neurological, endocrine, and immunological health effects have all been linked to POPs.
The most common routes of human exposure to flame retardants are through inhalation of contaminated dust in enclosed spaces at home or in the workplaces, and ingestion (of dust deposited on hands or of food contaminated with the chemicals). Some of the highest Brominated flame retardants exposures that have been determined were in offices and in electronics and electrical equipment waste (WEEE) recycling facilities. (Source: Recycling Plastics from WEEE: A Review of the Environmental and Human Health Challenges Associated with Brominated Flame Retardants)
The UNEP/GEF Global Monitoring project measures concentrations of POPs, many of which have been used as flame retardants, in air, human milk and samples of national interest. See the results in the interactive dashboard.
Brominated chemicals Management in Asia
In 2016, UNEP Chemicals and Health Branch collaborated with the Basel and Stockholm Conventions Regional Centers (BCRC China SCRCAP) in the execution of the project Capacity-Building for Environmentally Sound Management of PBDEs and Their Waste in Selected Asia-Pacific Countries to assist parties meeting their obligations in relation to newly listed persistent organic pollutants in the Asian region. The participating countries were Cambodia, Laos, Mongolia, Pakistan, Sri Lanka. Outcomes of the project include:
- Information platform on PBDEs management and operational activities
- video on Guidance on best available techniques and best environmental practices for the recycling and waste disposal of articles containing polybrominated diphenyl ethers (PBDEs)
- Brochure on The Application and Processing Technology of PBDEs
- Report on Feasibility Study on Separation of PBDEs Containing Waste from the General Waste Stream
Further Resources
Guidance on best available techniques and best environmental practices relevant to the polybrominated diphenyl ethers (PBDEs) listed under the Stockholm Convention UNEP March 2021
Chemicals of Concern in the Building and Construction Sector SAICM UNEP 2021
Guidance for the inventory of polybrominated diphenyl ethers (PBDEs) listed under the Stockholm Convention on POPs (Revised January 2017)
Stockholm convention BDE Section
UNEP Factsheet, December 2022
