The corrosivity of combustion products has arisen as an issue for both product manufacturers and standards bodies. While many industries can have concerns in this area, electronic communications and control equipment are especially vulnerable to the problem. The best way to manage the smoke corrosivity issue is to avoid a fire. In the event a fire does occur, a number of actions must be taken. An important consideration is that the materials and products used should have been chosen with due consideration of their corrosion-causing potential. To do this requires a suitable corrosivity test.
It has traditionally been assumed that smoke corrosivity is directly correlated to the emission of acid gases. The results of recent experiments have shown that materials which do not release acid gases can, nevertheless, cause corrosion of metal surfaces, as determined by metal loss. In addition, for electrical equipment there are two other types of related nonthermal damage from combustion products which must be considered, viz., ohmic bridging and degradation of contacts.
Laboratory tests proposed to date to measure the corrosive effects of combustion products all have significant deficiencies: some methods are not performance-based at all and are merely tests for pH. In others, unrealistic specimen heating or unrealistic exposure targets are used. To facilitate the development of a better test, a series of criteria have been developed. A specific test method was evolved from these criteria. The method is performance-based and incorporates realistic fire heating conditions.