Alkaline Detergent
An alkaline detergent is a cleaner with a pH above 7 —usually between 9 and 13 in professional use— that dissolves grease, proteins and organic matter. It is the product for kitchens, the food industry (CIP) and organic soiling; strong alkalis are corrosive and require gloves and goggles. For limescale and mineral deposits an acid is used, and for the daily maintenance of delicate surfaces, a neutral.
The alkalinity comes from bases such as sodium or potassium hydroxide, carbonates or silicates, combined with surfactants and sequestrants. In an alkaline medium fats are saponified and proteins swell and come away more easily; the surfactants emulsify the soil and keep it dispersed until rinsing. Effectiveness increases with concentration, temperature and contact time, which are always taken from the technical data sheet of each product.
It does not work against limescale or mineral deposits, which require an acid detergent. Strong alkalis attack soft metals such as aluminium and some sensitive materials, so it is advisable to check compatibility with the surface before using them.
Alkaline, neutral or acid: which to use
| Type | Indicative pH | For which soil |
|---|---|---|
| Alkaline | Above 7 (strong: 11-14) | Grease, oil, proteins, organic matter |
| Neutral | 6.5-7.5 | Light soiling, daily maintenance, delicate surfaces |
| Acid | Below 7 | Limescale, rust, mineral deposits, residues from alkaline cleaning |
Some Instaquim alkaline detergents, according to their technical data sheet:
- Clor NF Pro (pH 1 %: 11.9; from 2 to 8 % at 20–60 °C): chlorinated alkaline detergent-disinfectant for tanks, circuits and utensils in the food industry; sodium hypochlorite (4.50 % active chlorine) and sodium hydroxide. Leave to act for 5–15 min and rinse with plenty of water. Do not use on aluminium.
- Gras Foam (pH 1 %: 12.2; from 2 to 6 % at 20–60 °C): degreaser for floors, walls and heavily greased surfaces in the food industry, applied by foam projection, spraying, immersion or by hand. Do not use on aluminium.
- Bacter (pH 11.5; 4 % and 5 min for bactericidal effect): slightly alkaline detergent-disinfectant with didecyldimethylammonium chloride; causes severe burns (H314), so it is handled with protective gloves, clothing and goggles.