Millions of years ago, marine animals absorbed phosphates from the sea and concentrated them into their shells, bones, and tissues. The remains of these animals accumulated and, through geological changes, formed large rock deposits. This phosphate rock is mined and treated to produce phosphoric acid. The phosphates division of Aditya Birla Chemicals uses purified acid for food and detergent applications.

This technique is energy efficient and reduces fossil fuel requirements compared to alternative methods of phosphoric acid production. The process by-products (gypsum and clay) are used to fill the mined areas in the earth created by the removal of phosphate rock. This is called reclamation and means the land is returned to a useful and environmentally acceptable condition.

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The primary use of phosphoric acid is as a fertiliser ingredient but it has many other uses including metal treatment, food processing and the manufacture of technical and food grade phosphates. These phosphate powders are formed by a reaction with soda ash or other minerals and are used in products such as detergents and cleaners, baking powder, toothpaste, cured meats, cheeses and water softeners.

Phosphates are present in all living things - animal and vegetable and are continually required to support life since they are an essential nutrient for growth.

Given this essential role in life processes, phosphates are "generally recognized as safe" as a food ingredient by FDA Public Health Ministry, Thailand. They have a toxicity value similar to such commonly used ingredients as vinegar, baking soda and salt.

What happens to manufactured phosphates after they have been used? Phosphates from non-food applications are usually dissolved in water and discharged to municipal sewers. Since phosphates are required in human diets, they are also present in human waste in significant concentrations. These phosphates are also discharged to municipal sewers.

At the sewage treatment plant, biological and chemical treatment can easily remove 85 to 95 per cent of phosphates from the incoming sewage. However, not all municipalities in Thailand currently have the necessary facilities. As a result, some sewage is being discharged directly to waterways (lakes and rivers) with minimal phosphate removal. The government is committed to improving this situation by assisting in the construction of additional treatment plants.

During treatment, the phosphates are degraded to their natural form and concentrated into a sludge which is given to farmers as fertiliser for their land. The treated water which has less than one part per million of phosphate is then discharged to lakes and rivers and klongs (canals).

It is widely believed that phosphates from laundry detergents are responsible for excess algae growth leading to eutrophication. This is incorrect. In fact, the majority of phosphates enter the waterways from other sources such as agricultural and urban run-off, animal wastes and the atmosphere. These sources contribute large amounts of phosphates compared to the one part per million phosphate in treated water released by sewage plants.

It is important to understand and control the various sources of phosphates in order to manage the level of nutrients entering our waterways. Reduction of phosphate levels in detergents where sewage treatment exists will have very little effect on nutrient loadings.

There is now a greater awareness of contaminants in our environment. Although in most instances less is better, it must be recognized that minimum levels of phosphates are necessary to support the ecosystem. In summary, phosphates are safe, natural products mined from the earth, purified, used in many applications and finally returned to the earth as fertiliser. After examining the environmental path, the friendliness of phosphates becomes very apparent.