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Enzyme based additives for human waste treatment


The primary concern of any portable sanitation operator or end user is that the waste in a portable toilet looks acceptable and the fragrance is good. The added capability of the chemistry to break-down and suitably treat the waste is obviously more of a technical concern but is the more important issue both technically and ecologically.

All the applications for portable and off-line sanitation require an additive to treat the waste and the primary options available globally are as follows:

  1. Formaldehyde (Formalin based product) is a carcinogenic that has historically been used in cheaply treating human waste. More recently Formaldehyde has been banned in Europe and the USA yet is not banned in South Africa. It is however becoming more of an issue with several municipalities in South Africa banning or strictly controlling Formaldehyde use in their areas. The discharging of this waste in waste treatment plants is problematic and is either strictly controlled or not allowed. Does not operate as well in high – heat above 30 C.
  1. Non-Formaldehyde (less effective than Formalin, slightly more expensive) Glutaraldehyde based The only way to break the Biocide down is organically and once again larger STP’s can deal with them but the smaller STP’s (waste treatment facilities) cannot deal with Biocides. Less effective in high heat.
  1. Non-Aldehyde additives
    Quaternary Ammonium compounds are also Biocides and are very similar in operation to 2. above.
    Anti-Microbial additives are the most ecologically sound option which slows the growth of  bacteria and has the least impact upon STP’s. This additive is the most widely used product  in the USA and Europe. Less effective in high heat.
  1. Enzyme based treatments as below:

All toilet additives are typically destroyed by household products such as disinfectants, bleach, or antibacterial soaps. This includes the products utilised for cabin and bin cleaning which must not enter or be used in tank and urinal cleaning.  If any of these cleaning products enter the holding tank, then it should be triple rinsed prior to use.

‘Enzyme’ based waste treatment overview

Biological products have bacteria in them which produce enzymes that breakdown other bacteria such as the bacteria in human waste. This process takes more time and requires the right environment such as warm temperatures.

Bacteria producing enzymes is the most ecologically sound solution which treats the waste by breaking it down naturally with enzymes while it is not as effective in the short term as either of Formalin or Biocides, unless in hot conditions, and may be more expensive. The Enzyme based product can be so effective to the extent that the waste could eventually be compostable if effectively managed. Likes high heat.  Enzyme based products can also be considered as a pre-treatment for STP’s. When selecting an enzyme-based product, one should also consider whether the dye and fragrance are also of a bio-degradable nature

Enzymes are typically destroyed by household products such as disinfectants, bleach, or antibacterial soaps. This includes the products utilised for cabin and bin cleaning which must not enter or be used in tank and urinal cleaning.  It is always good practice to triple rinse the holding tank before switching over to enzyme-based solutions.  Any residue of high alkaline cleaning products left in the holding tank will also elevate the PH level, causing ammonia to form and kill off the natural enzymes and bacteria – rendering the product ineffective.


  • Portable toilets Natural enzyme deodorizer and waste digestor best used for lower traffic applications and/or extended service cycles. These use highly effective natural enzymes to control odour and liquefy waste and paper. It is non-toxic, 100% biodegradable and completely safe for all waste treatment facilities (STP) and septic tank systems. This product will not harm valves or seals.
  • Septic tank treatment helps prevent septic tank backups. Septic tank system enzyme treatment is a powerful and natural solution which destroys and liquefies waste. Monthly use of enzymes will help reduce scum and sludge while restoring the good working bacteria. Without a properly functioning septic system you risk build-up of surface and bottom solids that can carry over to your leach field and cause the leach field to clog. Once clogged, the system has nowhere to drain, and the tank fills up causing backup in the home and wet spots in your yard.
  • Grease Trap Treatment is formulated to digest grease.  Pump-outs are easier and are necessary less often.  It keeps the grease liquid and the outflow from the trap has lower BOD and FOG levels.  It is best applied metered at the end of each workday but can be applied by other methods according to directions.
  • Wastewater Treatment contains very high levels of micronutrients.  This product stimulates the already present micro-organisms into overdrive and supplies the lacking nutrients to accelerate their growth.  Again, the result is lower solids, grease, BOD levels and odour in waste streams.  By making the waste treatment plant more efficient, it can handle higher levels waste and more quickly.

These products all utilize the same naturally derived micronutrient technology.  These micronutrients produce accelerated breakdown of wastes. The intermediate odor-producing compounds are broken down to simpler no-odour components.  The overall result is lower solids, grease, BOD levels and odour in waste streams.

Because common cleaning products often destroy the normal bacteria population in septic tanks and grease traps, Septic Treatment and Grease Trap Treatment also incorporate specially developed strains of bacteria that target the wastes present.  You can incorporate fragrance into the Septic Treatment since it is targeted to consumer applications.


Water and Forestry department South Africa – sanitation guide 2007
BS EN 16194:2012 EU Portable Toilet Standard
SA WRC Report No. TT 414/09 September 2009
JJ Chemicals USA
Chembros CC technical
Prepared by Paolo Lupini