Ask G

Ask G: Is sodium percarbonate good for the environment?

This chemical is used as an alternative to nasty bleach, but is it really environment friendly?

I'd like to know about the chemical sodium percarbonate. I've seen it on the list of ingredients in things like nappies and laundry powder, but I'd like to know if it's a good green alternative or not.
-- Bronwyn

Washing powder

Credit: iStockphoto

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Sodium percarbonate is a bleaching agent used in various cleaning products. Also called sodium carbonate peroxyhydrate (PCS) and sodium carbonate peroxide, it dissolves at low temperatures making it an effective stain removal or bleaching agent in cold water.

When dissolved in water, it releases hydrogen peroxide and soda ash. It is often used in environment-friendly agents because it breaks down into oxygen, water and natural soda and is less damaging than sodium hydroxide and sodium perborate, known causes of soil contamination.

It has even been argued that sodium percarbonate has environmental advantages due to its release of oxygen into soils and waterways - but that has yet to be proven.

Generally, there is no such thing as a 'green' laundry detergent but there are a few things that you should look out for to ensure the product you are buying causes the least amount of damage to the environment.

Of all the ingredients in laundry detergent, sodium and phosphate are the most harmeful to soil and waterways. Due to the bad publicity surrounding phosphate and its affect on marine life, most laundry detergents limit the use of phosphate.

Labels such as NP (No phosphate) and P (complies with phosphate standards) are common but unlike food products there are no laws that require labelling of laundry products.

Independent consumer watchdog Choice recently did a survey on laundry detergents outlining not only top performing products but also the greenest.

While phosphate should be avoided because it increases the pH of soils and promotes algal growth in water ways, sodium should be avoided because it has the opposite effect.

For use in grey water systems, sodium levels should be less than 0.1 g/L. Increasing the amount of salt in soils can cause soil salination which makes it impossible for plants to grow and is difficult to reverse.

One label to keep an eye out for is the Good Environmental Choice Australia label. To gain this label, companies must comply with strict guidelines (available as a pdf here: including phosphate levels and the exclusion of other harsh chemicals.