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Effect of pH on FMDV
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FMD virus is inactivated outside a narrow range of pH conditions
(approximately pH 7 to 8.5) at a rate dependent on pH, temperature and
inactivant.
For disinfection of premises and equipment it is not generally necessary to go to the
expense of using proprietary disinfectants. The use of an appropriate acid or alkali,
together with a detergent to assist penetration of organic matter, is usually sufficient.
Many of the agents used are dangerous and all appropriate safety measures should be
taken, including the use of masks, eye protection and protective clothing.
Citric acid 0.2% solution
Ten per cent stock solutions may be held in airtight sterile containers for up to two
weeks. Effectiveness improved by addition of small quantity (no more than ml/litre) of
detergent. Suitable for milking equipment and bulk tanks. pH should be <4.
Formalin 10.0% solution (containing no less than 34% formaldehyde).
For use mix 1:9 with water. Suitable for spraying on hay, straw, bedding, etc.
Formaldehyde gas
Produced by action of formalin on potassium permanganate *Lethal – Danger*
Great care must be taken with the use of formaldehyde gas as it is extremely noxious.
This agent should only be used by experienced personnel with the appropriate equipment.
Ortho-phosphoric acid 0.3% solution
Effectiveness improved by addition of small quantity (no more than 3 ml/litre) of
detergent. Suitable for milking equipment and bulk tanks. pH should be <4.
Sodium carbonate 4.0% solution
Effectiveness improved by addition of small quantity (no more than 3 ml/litre) of
detergent. Suitable for animal pens and similar areas. pH should be >10.
Sulphamic acid 0.2% solution
Stable in solution, and particularly suitable for metal, painted surfaces, plastics and
rubber. Effectiveness improved by addition of small quantity (no more than 3 ml/litre)
of detergent. Suitable for milking equipment and bulk tanks. pH should be <6.
Proprietary brands
Labels will indicate their suitability for FMD and dilution rates.
Note that acid and alkali disinfectants, dependent for their activity
on pH, should not be mixed.
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