The impact of flame retardants (FRs) on the environment and human health has had a high profile for decades because of their persistence, bioaccumulative, carcinogenic and suspected endocrine disrupting properties. An additional concern that has gained prominence recently has been their capacity to kill and injure through toxic smoke, mainly generated by emissions of carbon monoxide and hydrogen cyanide.

“We have been advising our members as a matter of policy for the last three years that they should avoid using FRs mainly because of concerns about their environmental and health effects,” says Roberta Dessi, secretary general of the European Furniture Industries Confederation (Efic).

“Now research has highlighted the dangers of toxic smoke from FRs. We had assumed that fire safety was increased with these substances. This is an important additional danger.”

The growing number of studies questioning the effectiveness of FRs has led some to believe the risks outweigh their benefits. “The sector has big challenges at the moment,” says Sander Kroon, regulatory affairs manager at ICL-IP Europe, a major producer of brominated FRs (BFRs). “We have got to be much more proactive and work together in defence of FRs.”

The industry’s lobbying powers have been weakened by a split in its ranks. The European Flame Retardants Association (Efra), mainly representing BFRs and other halogenated products, has withdrawn from Cefic, while the Phosphorus, Inorganic & Nitrogen Flame Retardants Association (Pinfa), representing non-halogenated FR producers, has remained a sector group within it.

Efra has been disbanded, with the objective of creating a new group which will seek to shift the focuses away from the hazards linked to FRs. “The key issue is exposure not hazard,” says Mr Kroon, one of the leading figures in setting up the new organisation. “The public is hearing too much about the dangers, as described mainly by NGOs, and not enough about the effectiveness of FRs.”

For FR producers there is a pressing need to deal with growing hostility to FRs among customers sectors, particularly furniture manufacturers. The sector is one of the main consumers of FRs in both foams and fabrics.

In Europe, Efic has combined with other industry groups, like the European Bedding Industries Association (Ebia) and the European Federation of Building and Woodworkers, together with NGOs and firefighter trade unions, to form the Alliance for Flame Retardant-Free Furniture.

The alliance has just set up a website, which opposes the use of FRs, particularly as a result of a regulatory requirements for products like furniture and bedding to pass official ignitability and flammability tests before being put on the market. Instead, it favours greater use of smoke detectors, automatic sprinklers, self-extinguishing cigarettes and candles, and improved fire safety education.

Both sides of the debate need large, well-funded and resourced groups, because central lobbying is not enough. In Europe, even though testing protocols are drawn up at EU level, fire safety standards are initiated and enforced at member states under the subsidiarity principle and because of varying local conditions.

Elżbieta Bieńkowska, European commissioner for the internal market, told the European Parliament last September: “The EU should only undertake action if the objectives of fire safety cannot be sufficiently achieved by member states. Today, the Commission has no compelling proof that national regulations are not reaching this goal.”

The EU’s only national furniture-specific fire safety controls are in the UK and Ireland, where products have to pass ignitability and flammability tests. Since the UK’s Furniture and Furnishings Regulations (FFRs) were introduced in 1988, fire deaths there have decreased, recently by up to 50 each year. The regulations are now under review, with the objective of maintaining existing fire safety levels but with reduced FR use.

In the US, where states require pre-market testing of products, flammability requirements have been eased, primarily to reduce the use of FR chemicals. In California, for example, upholstered furniture can now be sold without FR foam.

The increased attention being given to the issue of smoke toxicity may result in changes to testing protocols for furniture, bedding and other furnishing, so that post-combustion emission of toxic gases will have to be measured. This may cause complications, because levels of toxic emissions can depend on variables like ignitability, flammability, ventilations levels and the sizes of rooms in which the fires occur.

Analyses of smoke content has shown that the major hazards for building occupants are carbon monoxide and hydrogen cyanide, because they cause relatively rapid asphyxiation. However, there are other acutely dangerous substances in smoke.

These include irritants like hydrochloric acid, hydrogen fluoride, hydrogen bromide and nitrogen oxides, which can hinder breathing by causing swelling in the throat. Others include polycyclic aromatic hydrocarbons (PAHs), particulate matter (PM), acrolein, sulphur dioxide, formaldehyde, dioxins and furans.

“All smoke is toxic, with substances like PAHs and PM that have no links to FRs being a major cause of injuries and fatalities in fires,” says Mr Kroon. “The priority is to protect occupants from the effects of all smoke by using FRs to give them more time to escape fires.”

Another category of high-risk chemicals is those which increase the density of smoke. Some regulators prioritise controls on chemicals linked to smoke density because it is the main factor hampering escapes by building occupants from fires.

One major problem is a lack of data pinpointing the source of the toxic chemicals in smoke. Few countries have regulations or mandatory testing schemes for measuring emissions of toxic substances from specific products during fires. Studies, some stretching back to the 1970s, have identified polyurethane foams as a source of hydrochloric acid emissions, but there is still a shortage of data on their ignitability and flammability in different types of finished product and fire conditions.

A UK and New Zealand team of researchers headed by Professor Richard Hull of the Centre for Fire and Hazard Science at the University of Central Lancashire, UK, attempted to fill some of the knowledge gaps in a paper published late last year. One objective was to find out why fires in bedrooms, living rooms and dining rooms caused 71% of all fire fatalities in the UK in the years 2009-14 despite accounting for only 13% of all fires.

To investigate the post-combustion effects of FRs on toxicity levels and fire growth rates in burning furniture and furnishing, the researchers tested four different fabric-filling FR combinations in sofa-bed mattresses on steel frames:

  • a UK-sourced fire retardant (UKFR) fabric and foam;
  • a China-sourced FR fabric with the same foam as the UKFR;
  • a fabric and foam without FRs for the mainland European market; and
  • a UK-made woven cover fabric, including cotton, wool, cotton wool and polyester fillings, designed to comply with the UK FFRs.

They concluded that meeting the regulations without FRs provides the lowest level of fire hazard in terms of toxicity. Although fire toxicity is the main cause of death and injury from fires in the UK, with a disportionate number of fatalities from upholstery and bedding fires, the FFRs have disregarded it. As a result, there is an overreliance on FRs to meet furniture flammability regulations, the study claimed.

The researchers decided that, once ignition occurs, the presence of FRs has little effect on fire growth rates but instead has an adverse impact on levels of smoke toxicity. The best performing product in the large-scale tests in the study was the one made mainly of natural materials without FRs, they concluded.

However, the FRs industry and fire science academics have criticised the study, mainly for focusing in the wrong place. “Professor Hull and his team concentrated too much on burning behaviour, while attaching insufficient importance to ignition,” says Peter Wragg, director of the UK-based Flame Retardant Textiles Network (Fretwork), which promotes discussion among specialists on critical technical issues in the sector.

Klaus Rothenbacher, a regulatory advisor at the International Bromine Council, told a Fretwork meeting in February that the paper did not consider at all how easily the materials in the study ignited. “Ignition is a fundamental parameter in fire safety,” he said. “FRs are intended to inhibit or stop the combustion process at point of ignition. Every second counts—the first few minutes are critical.”

In response, Professor Hull points to the scarcity of data on exactly how efficient FRs are in suppressing ignition and says that he believes that the study will be followed by more detailed studies focusing on this. “It was a proof of concept,” he explains. “Obviously with a such a small range of materials we cannot claim it is representative of the whole market.”

The study, which received a lot of media publicity after publication, especially in the UK, also briefly highlighted another increasingly prominent issue: damage to interior air quality caused by the relatively large amounts of FR dust prevalent in households with old furniture, where FRs have become detached from fabrics in upholstery, carpets and curtains.

Michael Warhurst of the UK-based NGO ChemTrust calls these pollutants “worrying”, because the FRs are routinely found in dust and there is a risk of children ingesting them. NGOs have also been expressing concerns about FRs contaminating recycled materials when circular economies become more prevalent.

While regulators appears to be holding back in taking action on previously low profile issues like toxic smoke and interior air quality, they are making greater progress in tackling FRs long suspected of being major hazards to health and the environment.

The BFR hexabromocyclododecane (HBCD) used in foams is being phased out globally as a persistent organic pollutant (POP), although the first of the specific use exemptions will not expire until November 2019. DecaBDE has now been officially scheduled for global phase-out after being listed as a POP under the Stockholm Convention. Other halogenated FRs are destined to be replaced by safer alternatives under REACH.

Echa is also investigating the safety of some phosphate FRs. In February, a public consultation ended on possible restrictions on the use of tris (2-chloro-1-methylethyl) phosphate (TCPP), tris (2 chloro-1-chloromethylethyl) phosphate (TDCP) and tris (2- chloroethyl) phosphate (TCEP). Under its community rolling action programme (Corap), the agency now has proposed evaluations of 17 FRs, mostly phosphates.

“These reviews can be expensive for the industry,” says Mr Kroon. “The more proposed evaluations are made, the more the industry has to spend on defending their products.through the collection of data.” And, one might adds, with smoke toxicity likely to become a major safety issue, this expenditure will rise even further.