Is Napisan a Safe Toilet Chemical? updated June 2019

Bacteria in septic tanks can be killed if the wrong chemicals are used. Pic: courtesy

Bacteria in septic tanks can be killed if the wrong chemicals are used. Pic: courtesy

Is Napisan a Safe Toilet Chemical in Septic Tanks?

Many RV owners ask ' is Napisan a safe toilet chemical in septic tanks .'

Safely disposing of toilet waste is a major problem when free camping. Safe 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.

Safe Toilet Chemicals

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. Further environmentally safe toilet chemicals are oxygen-loving bio-stimulants - such as live bacteria and yeasts.

Those known to be safe 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.

Unsafe toilet chemicals

There are two major risks, the foremost 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-odourisers 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 but kills bacteria: a problem if you use it in town sewerage systems. Do not, however, empty it into environmental or septic systems as that bacteria is essentially needed for their operation.

The second and related is move (in Europe) to using dry toilets, however as no water is used for flushing their surfaces are highly prone to dangerous microbial growth. To protect against this a biocidic chemical is added. Biocidic chemicals, however, kill all bacteria indiscriminately.This is a major issue if so-treated sewage is disposed in septic tanks - as such tanks rely on 'good' bacteria for their operation.

Is Napisan a Safe Toilet Chemical in Septic Tanks ?

Many RV owners suggest using Napisan (or similar) products. These, contain sodium percarbonate, a chemical that (in water), breaks down to soda ash and hydrogen peroxide. An additive makes the faecal matter smell less bad.

Napisan (brand) works well from an RV user viewpoint, but content information about other products is hard to obtain. This concerns as some may include chemicals poisonous to marine life. Some makers warn their product is safe to use in septic and similar systems.

Some products claim to be bio-degradable to Australian Standard 4351. But that Standard relates only to ‘surfactants’  - a detergent 'wetting' effect. It is irrelevant. These products are cheap but only border-line effective in breaking down faecal matter and reducing smells. Using them may damage the environment.

This issue can be avoided making your own 100% safe and ultra-cheap 'Napisan' equivalent. Just how is explained in Professor Ian Jenkins' associated article - see below.

Safe Toilet Chemicals - Napisan - a Professional View

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

The authoritative article explains the active ingredient (in Napisan and associated products) that does the job is from 25%-35% sodium percarbonate. 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. Click here to access it.

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

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