Disagreement over disinfectant dilution

25 March 2001



Disagreement over disinfectant dilution

By Fwi staff

VETS and chemical manufacturers are in disagreement over whether disinfectant dilution rates should be increased because of bad weather.

Makers of Ministry of Agriculture approved disinfectants urge farmers to strengthen dilution rates in cold, wet and muddy conditions.

Disinfectants are a vital tool in the fight to stop the spread of foot-and mouth disease. On Saturday (24 March) 560 UK cases had been confirmed.

According to Antecs Mark Blackwell, the concentration of disinfectant needs to be increased to ensure viruses are killed rapidly.

“This especially applies in the case of wheel dips when lorries pass over disinfectant mats in seconds.”

Alison Cox of DiverseyLever says producers deciding on dilution rates should appreciate how chemicals are tested to become MAFF-approved.

“Testing requires surfaces to be clean, dry and free from mud and organic contamination.

“This may not be practical on-farm and suggested MAFF dilution
rates may be ineffective.

“Stronger concentrations should be used in a foot-dip, which may be changed only once a day and be full of organic material, as well as on straw mats which have to cope with a lot of traffic.”

Bedforshire vet, David Chennells, agrees that disinfectants become less effective when contaminated.

But he argues that providing cleaning facilities first, not increasing the strength of solution is the answer.

“A boot-wash and wheel-wash containing a detergent should be provided to make sure surfaces are clean before disinfection,
otherwise the process will be ineffectual, said Mr Chennells.