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 Following a fire one distinguishes between primary and secondary damage. Primary damage is that which results directly from the incident such as the fire damage to buildings or contents. Secondary damage is simply explained as the contamination by smoke and corrosive substances, which are formed by combustion of materials, typically PVC. Normally secondary damage constitutes more than 75% of all damage.
 From experience we know that the formation of hydrochloric acid as a result of combustion of PVC is the main cause of corrosion after fire. Consequently our project managers carry out an analysis of the level of chloride in the surroundings, which indicates the amount of chloride acid formed by combustion. Further more the relative air humidity and the temperature are measured. The development of corrosion depends on the concentration of acid, the temperature and the relative air humidity. Read more about chloride analysis here. AREPAs services When establishing the requirements for a particular situation, the Project Manager will take account of the results of the chloride analysis, including a review of the ambient conditions to ensure no other sources of chlorides exists, the type of equipment affected and the one hundred and one other factors from the clients specific requirements to the current ambient conditions. In simple terms, the effects of the contaminants are eliminated or reduced by reducing the relative humidity levels in the area, by the application of corrosion inhibiting oils or by the immediate removal of contamination from sensitive surfaces. In practice, a combination of these methods will be used. Typically more than 1000 poisonous and corrosive gases are formed as a result of fire. Therefore there are different types of corrosion that can result from a fire. However generally, one would not perform tests for these unless specific information on the materials consumed by the fire and the activities normally performed in the premises indicated a potential risk. This covers substances such as hydrogen sulphide, which AREPA can only measure if we are called to site in the very early stages. Analysis of other substances would involve the services of an acknowledged laboratory. |
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