First steps to take after a fire.

With the advent of digital transmission protocols such as ISDN, ATM and SS7, the telecomm world has merged with the data processing world. The equipment used in each is similar in form and function. The improved efficiency of digital switching has concentrated large amounts of traffic into a small number of nodes, increasing vulnerability of the network to failures in these nodes. A single facility failure can paralyze the corporation.

Part of any disaster response plan is stabilization of the loss site and protection of the contents. Prompt emergency action will control damage due to contaminants and allow time for restoration of the equipment and facility.

Frequent redundant backups and offsite storage of media offer the best protection for digital data. Recovering data from damaged media after a loss is tedious and expensive.

Besides heat, a fire generates combustion byproducts that are an integral part of the soot, analogous to a fog that condenses on cool surfaces. An average EDP center or switching office will contain six tons of polyvinyl chloride (PVC) plastic. When heated, PVC generates hydrogen chloride gas. Combined with water, it forms corrosive hydrochloric acid. Other building materials form sulfates and nitrates. Even fire extinguishing chemicals such as Halon, exposed to the high temperatures in a fire, degenerate into hydrochloric acid, hydrofluoric acid and hydrogen bromide.

Soot generated by a fire which has consumed plastics and elastomers is a greasy, waxy substance composed of carbon, oxidized organics and other byproducts. Carbon on the surface of electronic equipment degrades its dielectric performance, especially in high-frequency and high-impedance applications.

Each fire has a unique chemical fingerprint in the soot, since the chemical components are determined by what burned. Soot-covered equipment which has been inundated with water often looks ruined. However, immediate action may allow the equipment to be restored.

Water associated with floods or fire suppression carries contaminants. Particulate matter and inorganic salts from building materials are deposited on circuit boards which have been exposed. Corrosion occurs. Once the metal is gone, it cannot be replaced.

The only effective long-term control is removal of the contaminant with carefully designed cleaning protocols.

The rate of corrosion is proportional to the amount of contaminant present. Since the most common corrosive contaminant in a fire is hydrogen chloride, quantitative tests should be run to determine the surface concentration of chloride. This can provide fast data on the concentrations of chemicals found at the scene.

The pH scale can determine presence of additional contaminants which are not detected by halogenide testing (such as sulfates and nitrates), and can corroborate halogenide surface concentrations measured. Any pH values below the typical 5.5 to 7.5 range are cause for concern.

The first warning signs will be the corrosion of mild steel hardware components. The most effective means of corrosion control is to lower the humidity to reduce the reaction rate; in short, to remove water. The steps are as follows:

WARNING: Do not energize any wet equipment. Remove power. Open cabinet doors, remove side panels and covers, and pull out chassis drawers to allow water to run out of the equipment.

Remove standing water with wet vacs. Use low-pressure air (50 psi) to blow trapped water out of the equipment. Absorbent cotton pads (diapers will work) can be used to blot up water. Use caution around header pins and backplane wire wrap connectors to avoid bending.

Try to preserve the critical data on magnetic media. Media exposed to contaminants should be examined by a professional before any attempt is made to use them. In trying to use a floppy disk with hard particulate matter on the surface, damage to the oxide layer may destroy data as the floppy spins. Water can dissolve the adhesive between the substrate and the magnetic oxide coating, resulting in loss of data. Tapes must be dry and clean before attempting to copy data. Hard disk data can be partially saved, even after a head crash. This labor-intensive process requires special equipment in a clean room.

If tapes are exposed to flood waters, keep them wet until they can be restored. Use zip lock bags, pack in a plastic lined box, etc. Keep in a cool area (under 65 degrees F).