Environmentally-Safe Flame Retardants for Polymers

Asahi Glass Co.

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With the increasing use of plastics in the manufacture of virtually everything from appliances to furniture to just about anything electronic, when a fire breaks out, the risk of injury or death is as great -- if not greater -- from toxic smoke as it is from the actual flames. To help combat combustibility, many manufacturers are using flame retardant compounds for producing plastic components, sheathing communications cabling, and creating stuffing and padding for furniture and other fixtures. However, many of these flame retardants, such as those containing halogen, are actually toxic and environmentally hazardous in many applications.

This new inorganic flame retardant is from Asahi Glass Co. of Japan. The new compound can be used in many of the most popular polymers and thermoplastic resins, such as polyethylene, polypropylene, polyester, polyvinyl chloride, polystyrene, nylon, and polycarbonate -- virtually any polymer with a softening point ranging from 100 to 300 degrees centigrade. The new compound is comprised primarily of a low-melting glass containing a large amount of a phosphorous substance. Upon combustion, this compound turns into a glassy material containing phosphoric acid, covering the surface of the polymer and cutting off oxygen, thereby suppressing the flames and effectively smothering the fire. In applications requiring small amounts of retardant, the new compound is more effective than aluminum hydroxide and magnesium hydroxide.

Untreated plastic chars and flames, potentially releasing toxic gases.

Plastic treated with Asahi product resists burning

When used with chlorine-containing polymers such as polyvinyl chloride (PVC) -- commonly used in household plumbing fixtures and other retail, commercial, and industrial products -- this new flame retardant also acts as a smoke suppressant by helping the production of a char surface on the burning material, reducing both flame and smoke. In fact, when this new flame retardant is used with PVC, the amount of smoke produced is reduced by ninety percent.

This versatile compound can be molded easily, making it ideal for applications such as plastic housings for electronic devices, seat cushions, automotive parts, plenum and riser communication cable sheathing, and more.