Chemical risks in detergents production
The origins of cleanliness date back to prehistoric times. Since water is essential for life, the earliest people lived near water and knew something about its cleansing properties.
Detergents were developed in response to a shortage of animal and vegetable fats and oils during World War I and II. In addition, a substance that was resistant to hard water was needed to make cleaning more effective. At that time petroleum was found to be a plentiful source for the manufacture of detergents. Today, detergents are mainly made from a variety of petrochemicals and/or oleochemicals (derivated from fats and oils).
According to recent trend, liquid cleansing products are outpacing the powder cleaning products.
Detergents can be found for example in:
- Laundry detergents: they are formulated to meet a variety of soil and stail removal, bleaching, fabric softening and conditioning.
- Dishwashing products: this includes detergents for hands and machine dishwashing as well as some specialty products.
- Household cleaning: they are used to clean painted, plastic, metal, porcelain, glass and other surfaces. Because no single product can provide optimum performance on all surfaces and soils, a broad range of products has been formulated to clean efficiently and easily.
Amongst the different manufacturers companies, we can find: Solvay, Henkel, Procter & Gamble, Unilever.
A detergent (or surfactant) is a chemical compound which has surfactant properties that make it capable to remove soils. It also often contains anti-microbial agents.
The first step of manufacturing these detergents is the selection of raw materials. Raw materials are chosen according to the many criteria, including their human and environmental safety, cost, compatibility with other ingredients, and the form and performance characteristics of the finished products.
Amongst these different ingredients you can find:
- Sodium hypochlorite helping whiten, brighten and remove stains.
- Alkalis (ammonium, sodium hydroxide). Alkalinity is useful in removing acidity, fatty and oil soils.
- Acids (nitric acid, acetic acid, hydrochloric acid, sulphonic acid) to neutralize or adjust alkalinity of other ingredients and because some specialty cleaners need extra acidity to remove mineral build up.
- Colouring agent (pigments or dyes).
- Solvents (ethanol, isopropanol, propylene glycol) to prevent separation or deterioration of ingredients in liquid products and dissolve organic soils.
Most exposed working places
- Decanting process and storage of raw materials.
- In the case of manufacturing liquid detergents:
- Premixing manufacture: Liquid detergents contain a combination of soap and surfactants. These are made first as a premix, after which other ingredients are blended into it. This stage simply consists of neutralizing fatty acids with either caustic soda or potassium hydroxide.
- Ingredient mixing: All ingredients are added and mixed at a high temperature. The ingredients used in the manufacturing of liquid detergents are usually caustic soda, sulphonic acid, perfume and water.
- In the case of manufacturing powders: Several methods can be used to manufacture detergent powders (spray drying, agglomeration, dry mixing). In any case, dry and liquid ingredients are first mixed. Consequently this step present chemical hazard.
- Control and R&D laboratory: tests are made in order to check the quality and efficacy of the detergents, to improve and to create new formulations.
- Detergents packing and storage.