Safe toilet chemicals – can Napisan be used in septic tanks?

by | Dec 7, 2019 | Articles, CBRV, CMB, General, Health & Safety, Travel

by Collyn Rivers

Safe Toilet Chemicals

Safe toilet chemicals are essential, but some toilet chemicals kill essential bacteria in septic and environmental systems: some are toxic – this article explains all.

To safely dispose of toilet waste is a major problem for caravan and motorhome owners who free camp. Safe toilet chemicals are essential as faecal matter endangers humans. Many toilet chemicals, however, contain non-biodegradable content. Worse, they kill essentially needed bacteria in ‘long drop’ and septic systems.

Caravan toilet chemicals

Pic: johnwatsonplumbers.com.au

Safe toilet chemicals

So-called bio-stimulant products are environmentally friendly. Adding oxidising agents (or enzymes), speeds up nature’s breakdown of faecal matter. It also reduces smells.

You can empty safely treated sewage into septic and sewage treatment plants, but not some so-called environmental systems. Environmentally safe toilet chemicals are oxygen-loving bio-stimulants – such as live bacteria and yeasts.

Known to be safe toilet chemicals include Bio-Pack, Odour-B-Gone, Aqua Kem Green and Aqua Kem Rinse (but not necessarily related products), and BioMagic.

Their makers claim Envir-Chem, Reliance Bio-Blue, Century Blue Clean N Fresh, and Chempace bioFORCE to be safe.

Biocides kill all bacteria

Biocides kill all bacteria – good or bad. If you treat toilet waste this way it becomes allergenic: some people claim it possibly triggers cancer. Adding a further chemical reduces the stench of sewage broken down non-aerobically.

The industry claims that sewage so-treated is disposable in sewage treatment plants. Biocidic chemicals, however, kill bacteria indiscriminately. This causes many that rely on septic tanks to have a concern about their facilities.

Never use formaldehyde

The major risk to the ecology is formaldehyde. The US Department of Toxic Substances Control states: ‘Chemical toilet additives include chemicals that are known to cause septic tank failures by killing the bacteria essential to the treatment process in the septic tank. Formaldehyde can thus cause these to die in holding tanks as it controls odour by killing bacteria. When a septic system fails, sewage waste does not break down. It can cause an increased risk to people in contact with raw sewage.’ The Department also warns against de-deodorisers such as Bronopol, Dowicil and Glutaraldehyde.

Check the declared content of any product. One, promoted as ‘environmentally safe’, has the (obligatory) Material Safety Data Sheet stating it contains Bronopol. Chemtech’s Portasol claims to be environmentally friendly, but its data-sheet states it contains 10 g/L Glutaraldehyde.

Be wary of home-made chemicals. Most contain bleach or Pine-O-Clean. Such material is cheap and effective, however, kills essentially needed bacteria. This is not a problem if the waste is disposed of in town sewerage systems. Do not, however, empty it into environmental or septic systems.

Is Napisan a safe toilet chemical?

Many RV owners suggest using Napisan (or similar) products. Napisan and its many ‘look-alikes’ contain sodium percarbonate. This, in water, breaks down to soda ash and hydrogen peroxide. An additive makes the faecal matter smell less bad.

This works well from an RV user viewpoint but content information, however, is hard to obtain for look-alikes. These may include chemicals that are poison to marine life. Some makers warn they are not safe to use in septic and similar systems.

Some such products claim to be bio-degradable to Australian Standard 4351. But that Standard relates only to ‘surfactants’ – a detergent ‘wetting’ effect. It is thus not relevant.

These products are cheap. They are, however, only border-line effective in breaking down faecal matter and reducing smells. Using them may damage the environment.

Napisan – a professional view

Emeritus Professor Ian Jenkins (previously Professor of Chemistry at Griffith University) has kindly provided an independent professional opinion on safe toilet chemicals. 

The authoritative article explains the active ingredient (in Napisan and associated products) that does the job is sodium percarbonate. It contains from 25%-35%.

You can buy sodium carbonate (100%) in bulk. Brewing supply companies sell it for about $5.50 a kilo. Emeritus Professor Jenkins explains how to use it.

Use only safe toilet chemicals

You can safely use proven bio-friendly toilet chemicals to treat sewage for city sewage treatment plants. But if you travel a lot, be 100% certain the chemicals are bio-friendly. If not you can ruin costly septic systems.

If you find this article useful you will enjoy reading my books. They are technically sound and written in plain English, They Caravan & Motorhome Book, Camper Trailer Book,Caravan & Motorhome Electrics, Solar That Really Works and Solar Success. To find out more information about the author Click on Bio.

This article is copyright rvbooks.com.au – it may not be reproduced in any form. If you wish to make others aware of it please use the only first paragraph plus this LINK/

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Collyn Rivers is a semi-retired automobile research engineer.  He is the author of seven books, five of which are about making RVs and solar work optimally.

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ISBN: 978-0-6483190-5-4.

How to Choose and Buy an RV

How to Choose and Buy an RV is the ultimate guide for those times when you want to, well, choose and buy an RV.

eBook versions

Paperback version

Prices for the paperback version including delivery can vary dramatically.  RVBooks recommends you shop around.  We've included a number of reputable booksellers you may wish to consider. Any bookshop, whether online or bricks and mortar, can order copies of How to Choose and Buy an RV. Just ask.
ISBN: 978-0-6487945-5-4.

The Caravan & Motorhome Book

The Caravan & Motorhome Book covers every conceivable aspect of campervan and motorhome usage. If you own a camper van or motor home, you'll want this book.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of The Caravan & Motorhome Book. Just ask.
ISBN: 978-0-6483190-5-4.