Follow this process in order to understand the basic chemistry and principles of the cleaning that we do during a fire mitigation job.
1. Solvent Action
Most water-based cleaning products used in fire mitigation are alkaline (pH 7-14) because smoke residues are usually acidic (pH < 7). The higher the pH is, the more aggressive the cleaning product will be. Note: pH is a measure of the concentration of hydrogen atoms in a given solution.
Because smoke residues are often oily, a solvent is required to remove them - a solution in which the residue can be dissolved for removal. Each type of solvent can dissolve different things. Water is the most common solvent to use (sometimes called the 'universal solvent') but organic solvents may be used for greasy, oily or waxy things.
2. Chemical Reaction
In this type of cleaning, the product used will react with the substance and create a third substance that can be easily wiped away.
Example: Rust (oxidized metallic residue) reacts with acidic cleaning products. Then it can simply be washed away.
3. Lubrication
Lubrication is the act of reducing friction between the surface and the smoke residue. This allows for removal of the residue without scratching the surface.
Example: Vegetable oil soap is often used on finished wood surfaces that won't be damaged by water.
4. Agitation
Agitation is the act of using physical force to suspend soot and smoke residue. The tool used may be soft (terrycloth towel) or hard (bristled brush) with the level of contamination and type of surface determining the cleaning agent used.
5. Temperature
Cleaning under high temperature causes faster results because chemical reactions occur more quickly, pores become open, and the material dries more quickly. Always check to make sure the surface can withstand high temperature.
6. Dwelling Time
Dwell time is the amount of time during which a cleaning agent is in contact with the contaminated surface. Follow the manufacturer's instructions regarding dwell time, as it changes from product to product.
