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TECHNICAL BRIEFING ABOUT HALOGEN FREE:

The most common halogenated insulating material is polyvinyl chloride. Plasticized PVC compounds have been

used for decades for insulation and jackets for building wires. Southwire Company and Union Carbide

Chemicals and Plastics Company, Inc. have worked to develop several zero halogen polyolefin based insulating

materials as an alternate to PVC. The fire retarding effect of polyolefin based reduced emission compounds is

brought about by the use of hydrated mineral fillers. Up to 30% of these fillers is hydrated water that is

released in a fire situation. When exposed to flame, available heat is used to volatilize the water of hydration,

thus cooling the flame and slowing decomposition. The water vapors will block the oxygen supply from the

fuel, and the fire may be extinguished or its progress may be retarded.

Conductor insulating materials containing halogens(LIKE PVC) have been used for many years. The halogens

found in insulating materials are chlorine, bromine, and fluorine.

Halogens improve certain properties such as flame, chemical and oil resistance but also have some HUGE

NEGATIVES. Gases produced during combustion of halogenated insulating materials react with moisture to

produce halogen acids; for example, hydrogen chloride forms (HCl) and hydrogen bromide forms HBr . These

acids are Highly corrosive and Toxic.

Toxic Cabling

Cabling: What You Don't Know Can Kill You

Halogen cabling emit toxic fumes in a fire . These fumes kill more than the fire would..

Most of the cable contains halogens , which release toxic fumes when they burn. In a fire, halogen cable can

release acid gases that sear the eyes, nose, mouth, and throat. The fumes can disorient victims, prevent themfrom escaping the blaze, can cause severe respiratory damage and hinder rescue operations . In short, they

can kill. Hence, many a government have moved to safer, zero Halogen cables.

Halogen insulation helps prevent cables from catching fire and in case of a fire situation the fumes emitted

from a zero halogen cable are negligible and non-toxic.. "Fluorinated polymers are hundreds of times more

toxic than zero-halogen cabling," comments Marcelo Hirschler, a consultant with BGH International Inc. (Mill

Valley, Calif.), a firm that specializes in fire-safety issues. "They're also far less flammable."

McCormack believes the code should be changed to restrict the use of halogen cabling, which some tests show

to be more than five times as toxic as its acid-free equivalent.

It has been proven that Halogen cables should be banned because of the catastrophic effect acid fumes have

on computer circuitry--causing millions of dollars worth of damage even in small fires. "Corrosivity is the

Achilles' heel of halogen cables," comments Michael Keogh, corporate fellow at Union Carbide Corp. (Danbury,

Conn). "It's a matter of machine toxicity, not human toxicity." Union Carbide makes the raw materials used in

both halogen and halogen-free cable

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Many countries--including Australia, France, Italy, Japan, Korea, New Zealand, and the U.K.--have also moved

to halogen-free cabling. And even in countries where the choice of cable is still left to the installer, zero-

halogen is becoming the technology of choice, according to IBM's Erba. "Halogen-free cables account for 40

percent of the total communications cable in Europe," he says. He believes that the remaining 60 percent is

PVC ( Halogen) sheathed.

In order to meet rigorous international toxicity specs cable manufacturers avoid halogens altogether, instead

adding metal hydrates to their polyethylene and polypropylene cable insulation. When heated, these

chemicals release steam.

When the PVC cables used in building risers burn they emit both hydrogen chloride (an acid gas) and dioxin,

which Greenpeace, the environmental advocacy group, calls "the most toxic synthetic chemical known to

science". Long-term exposure to dioxin has been linked to a number of health problems, including cancer,

reproductive disorders, birth defects, impaired neurological development, diabetes, and immune system

suppression.