Disinfecting – Must Haves From A Disinfectant
Important facts to consider when looking at surface sanitising:
In a time where surface sanitising has become a vital part of cleaning, it is important to understand more than ever before about what, where and how to disinfect and the key factors that should be considered when choosing the right disinfection technology:
- Environmental effects
- Health and Safety
Minimal Infectious Dose
The key to effective disinfection is to understand how contagious bacteria and viruses can be. Rates can vary depending on the strain, however as few as 10 viral particles or bacteria can trigger infection in an individual.
Effective kill rate
Companies and standards use log reductions to prove efficacy of products against a variety of bacteria, fungi and viruses. It is vital that the log reductions reduce the contaminated area to below 10 particles to ensure protection. While levels of bacteria and viruses vary depending upon locations, regularity of cleaning and surface type, sneezing and coughing releases hundreds of thousands of particles and contaminated areas can carry millions of microbes. A product can kill to:
- 3-log reducing 10,000 particles to 10 but anything above that level leaves a potential for infection
- 4-log reducing 100,000 particles to 10
- 5-log reducing 1,000,000 particles to 10
- 6-log reducing 10,000,000 particles to 10
Typically, a minimum of 5 log is required to ensure that contaminated areas can be disinfected. Speed of effectiveness and conditions are less important than the kill rate itself as these can be dealt with on site.
Nothing is more important than effective kill.
- There is no official BS EN test for the residual effectiveness of sanitisers against bacteria or viruses and hence no tests currently listed by the European Chemicals Agency to demonstrate residual activity under the Biocidal Products Regulation (BPR)
- PAS 2424:2014 exists as a working document exclusively for the 24-hour residual effectiveness of disinfectants against some bacteria and one yeast. It is important to note that this is not an official BS EN test and may ultimately change. PAS2424:
- Products must have passed EN13697 (the standard surface test requiring a 4-log reduction) under appropriate conditions
- Incorporates a series of physical abrasions and the re-application of the test organisms to the test surface to simulate day to day conditions, as disinfected surfaces will rarely, if ever, stay pristine and untouched
- Is designed to test for a period of 24 hours only.
- Must be tested against strains of the bacteria Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae and Escherichia colialong with the yeast Candida albicans
- Must be conducted under dirty conditions. This is obligatory
- Requires a 3 log (99.9%) reduction in microbial numbers to pass the test. This is a potential issue – a minimum infectious dose ranges between 10 and 100, a 3-log reduction would only give acceptable disinfection on surfaces with less than 10,000 particles
There is also the more general question of microbial resistance or tolerance. Exposure to sub-lethal concentrations of biocide can allow some species of bacteria to develop a degree of resistance or tolerance and, as biocides and antibiotics share some mechanisms of action and resistance, it is not surprising that such biocide-tolerant organisms have shown cross-resistance to antibiotics under laboratory conditions.
Although there are few, if any, cases of clinical biocide failure or significant antibiotic resistance caused by industrial biocide use, the fundamental mechanisms are the same and there have been further scientific papers recently published which reflect this concern. The over-use of biocides or microbial exposure to sub-lethal levels of same is not sensible practice and should be actively discouraged.
It is also questionable whether leaving residual concentrations of biocide on surfaces is actually desirable. Technologies that are chlorine or QAC-based are harmful and damaging to the environment even when used at concentrations where hazard information does not need to appear on the product label or SDS.
Alkyldimethylbenzyl-ammonium chloride (widely used QAC) for example carries classifications such as:
- Skin Corrosion. 1B (H314)
- Acute Tox. 4 (H302)
- 1B (H350)
- Aquatic Acute 1 (H400)
- Aquatic Chronic 1 (H410)
It is important to remember that although the product being used my not have all these warnings, the technology itself is still causing that damage and when sold in the millions of litres can have long lasting and widespread ecological damage.
Health and Safety
Safety and Rinsing
BioHygiene offers the safest cleaning options available on the market carrying a lower hazard classification than competitor equivalents. BioHygiene replace undesirable ingredients wherever possible with eco-solvents, plant and fermentation extracts, naturally derived sustainable surfactants, naturally occurring non-hazardous bacteria and enzymes. BioHygiene cleaning products are not only safer for the environment but for the end user as well.
Typical hazard warnings on quat based technologies include skin irritation, eye damage, very toxic to aquatic life with long term effects, may be corrosive to metals and carcinogenic whereas for bleach and hydrogen peroxide we see warnings such as causes serious skin burns and eye irritation.
All Purpose Sanitiser contains a food grade natural sanitiser and an amine-based biocide without an MRL (meaning that it leaves no residues behind) as well as an industry standard ecosurfactant for cleaning.
The industry recommends that food contact surfaces are rinsed before use after a biocide is used.