Surface Disinfectants

Should Disinfectants be rinsed or left to drain/dry?
Surface Disinfectants supplied by Holchem are not designed for disinfecting food stuffs. However, it has long been established practice not to rinse disinfectants from food contact surfaces. This practice has been acceptable to BRC and Retailer Auditors, and indeed in animal processing areas it has not been questioned by Ministry Vets. The current legislation regarding the disinfection of food premises is contained within the Food Hygiene (England) (Scotland) (Wales) (Northern Ireland) Regulations 2006, which enacted within the UK, EC 852/2004 on the Hygiene of Foodstuffs and EC 853/2004 on the Hygiene of Foodstuffs of Animal Origin. There are, however, no specific requirements relating to the use or removal of disinfectants beyond the requirement that “food premises are cleaned and, where necessary, disinfected”. In previous legislative instruments in force throughout Europe there were specific needs with regard to the use of disinfectants – however these were repealed in 2006 when the afore-mentioned regulations were enacted onto the UK statute books.
Clearly at the end of cleaning there may be a need to reduce any residual microbial loading to a safe level by use of a disinfectant. This disinfectant must be left in contact with the surface for sufficient time to be effective.
After suitable contact time, disinfectants can be rinsed away with potable quality water. However, if a plant is to stand idle for even a few hours before production restarts there is an opportunity for re-infection of surfaces by settlement of airborne particles, or by drips from pipe work and overhead equipment. The presence of non-rinsed residual disinfectant therefore has a secondary function as a preservative to inhibit microbial growth. Rinsing the disinfectant away clearly removes the preservative function; there is then a risk of food contamination. Indeed the action of rinsing with potable water may be sufficient to settle airborne micro-organisms on to a surface; once again leading to potential food contamination.
Disinfectants supplied by Holchem and other reputable manufactures are not classified as “Toxic”, however, we recommend that a site risk assessment should be undertaken to decide whether to rinse or not.

Will Residual Disinfectant Physically Damage Food Stuffs?
If disinfectant can pool rather than drain freely “and” there is a possibility for food stuffs to pass through or across the pool, such that they become discoloured or soaked in liquid, then clearly procedures should be put in place to either rinse away the pooling or to allow it to drain. This should be considered as part of a risk assessment.

Organic Production and Disinfection
When producing food stuffs to Organic Status it is essential, that after leaving disinfectant for sufficient time to be effective, all residues are rinsed away with potable quality water before production commences. The only exception to this is when alcohols are used for disinfection; these will evaporate to leave no residues.

Will residual Disinfectant cause taint to Food Stuffs?
Disinfectants supplied by reputable manufacturers are independently assessed for taint potential using well recognized tests. These are generally conducted blind using a trained panel of “tasters”. Tests are conducted using high fat materials (butter, chocolate etc.) that are impregnated with disinfectant. These high fat materials are chosen because fatty material is most likely to absorb taint elements.
Products supplied by Holchem, listed below, have all been taint tested by Campden BRI; copies of the reports are available on request: Terminol, Perbac OPD, Holquat, Alcosan & Dual

Will residual disinfectant damage equipment?
Disinfectants used in the UK food industry tend to be manufactured by companies who specialise in the food industry. They are well aware of the chemical properties of materials used to construct food processing and ancillary equipment. Great care is taken to ensure that formulations do not cause damage to equipment. However, it is advisable to always check product data sheets for compatibility, particularly if equipment contains soft metals such as Aluminium, Copper, Brass or Zinc.

Will residual Disinfectant cause Harm to the Consumer?
This perhaps is the question of greatest concern.
Consulting the MSDS supplied with any chemical is instructive. In sections 2 and 15, the classification of the formulation will be given. We are not aware of any supplier providing a disinfectant that has a “Harmful” (R20,21,22) or “Toxic” (R23,24,25,26,27,28) classification.
Investigating section 3 of an MSDS will reveal information about each component that makes up the final composition, if any of the components were Toxic they would be declared here.
Again we are not aware of any supplier in the UK marketing a surface sanitiser with toxic components. However, customers should satisfy themselves that chemicals used for cleaning and disinfection do not have a toxic or harmful classification.
Perhaps the most instructive information, currently available, when assessing toxicity potential is to look at LD50 data for the components of a disinfectant.
If we take Holquat, Terminol and Alcosan as the main disinfectants supplied by Holchem, the LD50 values for all of the components are readily available. It is a simple matter of calculating how much of each disinfectant it would be necessary to consume before any of the LD50 values were exceeded. The table below shows this data for a 75Kg person.
Taking the lowest LD50 concentration for each product, we see that for Holquat it would be necessary to consume greater than 111 litres of a 1% solution before there is a risk of exceeding an LD50 value. For Terminol and Alcosan the figures are lower (greater risk), but are still sufficiently high as to be unlikely. Hence incidental consumption of non-rinsed disinfectant is unlikely to pose a health risk to the end consumer. Holchem will continue to review this data as new information becomes available.