Toilet chemicals and alternatives

In view of the often asked question on toilet chemicals or all about using nappy powders, the following says it all:

Old fashioned toilet chemicals were basically Formaldehyde, which is a harmful chemical in the environment. It doesn’t enhance the bio-degrading of the human waste as it is a preserving agent. Some 'green' alternatives contain Bronopol which breaks down into Formaldehyde. These chemicals should be avoided.
There are many safer products available such as Bio Magic and Odour-b-gone tablets.

A popular and successful alternative is Sodium Percarbonate in the form of nappy soaker powders. Products widely available that contain principally Sodium Percarbonate (34%) include Select Oxygenated Soaker and Stain Remover or Homebrand Laundry Soaker & Inwash Booster have superseded Woolworths Homebrand Nappy Treatment Plus, Aldi stores Di-San Nappy and Laundry Treatment, and Supreme Oxy Active which can be purchased from Red Dot stores. Note that Woolworths Homebrand Laundry Soaker & Inwash Booster now only contains 28% Sodium Percarbonate which will work, but users may prefer to find products still with 34%.


Coles nappy soaker has been superseded by the laundry soaker Coles Laundry Booster. Similar products can be purchased at some of the 'cheap shops' - read the label. Most other brands contain other ingredients and less sodium percarbonate. These sodium percarbonate 34% nappy soak powders are also good products for doing the laundry in buckets whilst travelling. For more about the composition of these powders, you can check the Material Safety Data Sheets
















Dissolve a ‘shake’ (around a level lid full) in a litre or two of water and add to the cassette after first use following emptying. The movement of the caravan mixes it well even if not pre-dissolved, however some liquid needs to be added when starting. If used for ‘nocturnal wee visits’ only, the product is said to be not as effective, in which case more frequently emptying of the liquid is an easy solution. It is best to use no other additives (such as agents to give out a pleasant smell) as they may reduce the effectiveness of the Sodium Percarbonate.

We were using Bio Magic and often only used the toilet once before emptying it a few days later as we only use it when we were camped where there were no amenities. I tried the Sodium Percarbonate products and was even happier with the results. It is also a much cheaper product to purchase, so do not mind emptying after only one use if at a dump point when we think we may be some days away from another.

These Sodium Percarbonate products are considered septic and pit toilet safe, and when burying in the ground the slurry disappears quickly and leaves no harmful chemical traces such as the old formaldehyde 'preservative' type toilet chemicals do.

Products consisting of enzymes may be even safer for the environment alternative.

If your cassette has been used with chemicals, wash it thoroughly first. Likewise the flushing tank if any chemicals have been used in it. Then soak it in a stronger than normal solution of your chosen product for twenty four hours.
No additives are needed in the water in the flushing tank, but if desired, some Sodium Percarbonate powder can be added. Previous use of ‘top tank’ chemicals can result in a residue build up and Sodium Percarbonate solution will remove these. It is important to thoroughly cleanse the top tank as well as the cassette if changing from other chemicals.

If you are prepared to empty more frequently, like on alternate days, you do not need any additives. People using the Vacu-flush toilets or have the SOG extractor fan fitted do not need additives, but may choose to do so. Additives are really only used to avoid or mask odours for the person emptying the cassette.


When emptying, seek an authorised dump point (many caravan parks have them). If burying the waste, ensure you dig deep, are at least 100 metres away from any water course, a kilometre away from any habitation (town or rural buildings), and well away from the road, preferably not near a rest area. You are not permitted to empty within a National Park, Conservation or Nature Reserve. Stop where you can safely pull off the road, but where others are unlikely to stop, ie not near a rest area and walk some way from the road, but not of course onto private property. If emptying onto a toilet, ensure that any splashing is cleaned up. Best not to have people see you head towards the toilet block with your cassette as they may think of the harmful Formaldehyde chemicals and have no way of knowing that yours will not harm the sewerage system.

The above is an extract from my Toilet Chemicals article which has the most up to date products and information.

Read this and our other travel tips at Travel Tips and Hints

This Blog last updated 29th April 2017.