Backgrounder: Alternatives to decaBDE

Apr 24 2007

INTRODUCTION

· DecaBDE is used as a fire-retardant in TV enclosures, electronic products, textiles, plastics and wires.

· The widespread use of highly-brominated substances such as decaBDEs is of significant concern to human health because they are persistent, bioaccumulative and toxic. Further, when decaBDEs are ignited in the instance of a fire, highly toxic chemicals are released, which creates a further danger.

· Given these concerns, alternatives to these chemicals should be used.

· Alternatives to decaBDE exist and are on the market, but are not being pursued as actively as they could be because decaBDE is cheaper. The use of alternatives should be mandated by regulation to even the corporate playing field in the production of fire-retardants while ensuring fire safety.

· There are three primary alternatives to using decaBDE. The alternatives discussed favour chemicals that are non-brominated and non-halogenated to avoid the harmful characteristics of decaBDE itself.

The alternatives:

1. Substitute another chemical substance.

2. Substitute another product material that doesn't depend on decaBDE to achieve flame-retardation.

3. Redesign the objects themselves so that they are inherently less flammable and therefore do not require the addition of this chemical to make them so.

USE IN TELEVISION SETS

· DecaBDE is used in the production of a plastic called high impact polystyrene ("HIPS"). This plastic is often incorporated into the front and rear enclosures for television sets. Research indicates that such enclosures for consumer electronics account for 80% of all decaBDE used.

· A high level of flame retardancy (V-0 or higher) is required when the object is located less than 50 mm away from a potential source of ignition. A standard television requires this level of retardancy.

Alternatives

· Modified resin systems are the most promising alternative to decaBDEs in the context of TV enclosures and consumer electronics. Alternative flame retardants can then be added to the resin. Typical alternative flame retardants are phosphate and phosphonate compounds, which do not make use of bromine.

· In the instance of a fire, the phosphorous compounds quickly form a non-combustible layer around the object. The phosphorous compounds actively intervene in the fire when it is still in a liquid or condensed state. This in turn reduces the fire's combustibility.

· In the case of television sets, the use of a different blend to replace HIPS - decaBDE would result in a marginal price increase for a typical TV of 1.5% -2.5%, or about $7.50 on a $300 TV set.

Resin

· There are three plausible types of non-brominated resins that should be considered:

1. PC with ABS blend (polycarbonate with acrylonitrile-butadiene-styrene) with added flame retardant substances;

2. HIPS with PPO blend (polyphenylene oxide) (more frequently used in Europe than in North America);

3. Polycarbonate resin alone – when combined with phosphate ester, fire-retardancy is achieved.

Other

· Bioplastics derived from corn and other agricultural substances

· Changes in design and construction (e.g. separating high voltage components from lower voltage)

USE IN TEXTILES (mattresses, industrial/commercial drapery and upholstery)

· Textiles account for 10-20% of worldwide use of decaBDE

· The textiles are often backcoated in or immersed in decaBDE to protect the furniture foam from combustion

· The use of decaBDE in textiles has been favoured in commercial use because it helps the furniture withstand multiple industrial-strength washes and reinforces the item's overall durability.

Alternatives

· Use of inherently flame-resistant fibre and/or fibre blends – these burn very slowly and often self-extinguish

· Treating fabrics with a organophosphorous chemical or tightening the weave of a fabric – this modifies the fibre's makeup in ways that renders it more flame retardant

· Use of barrier technologies, as in mattresses and chairs – placing a barrier of inherently flame-resistant material between the exterior fabric and the inside material increases flame-retardancy.

USE IN OTHER PLASTICS

· The use of decaBDEs in plugs, electrical outlets and sockets.

· These items account for 2-3% of decaBDE use.

Alternatives

· Other brominated flame-retardants are available. One producer states its product is non-hydgroscopic, not toxic, not soluble in water, not hydrolized in water, and does not release phosphoric acid.

USE IN WIRES

· DecaBDE is used in this instance to prevent ignition of cable coatings

Alternatives

· Several non-brominated substances currently exist on the market, such as ammonium polyphosphate, magnesium hydroxide and melamine phosphate, and actually are often superior in performance to decaBDE.

References:
Lowell Center for Sustainable Production, University of Massachusetts, Lowell. Decabromodiphenylether: An Investigation of Non-Halogen Substitutes in Electronic Enclosure and Textile Applications. Prepared by Pure Strategies, Inc. April 2005.

Maine Department of Environment Protection and Maine Centre for Disease Control and Prevention. 2007. Brominated Flame-retardants: Third annual report to the Maine Legislature. January 2007.

The Swedish Chemicals Inspectorate. Survey and Technical Assessment of alternatives to Decabromodiphenyl ether (DecaBDE) in Plastics. Stefan Posner, Linda Börås. KEMI Report No. 1/05. Stockholm, June 2005.

Based on research conducted by Mary Lou McDonald, a volunteer at Sierra Legal, for further information contact Elaine MacDonald, Senior Scientist at Sierra Legal, 416 368-7533, ext 27.