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Disinfection on aquaculture sites


Frequent and thorough cleaning and disinfection are crucially important measures in the biosecurity plan of any aquaculture facility.  As the efficacy of disinfectants is severely decreased by the presence of organic matter; it is extremely important to precede disinfection with thorough cleaning. 

The cleaning and disinfection process outlined below is recommended for all aquaculture sites:

  1. Remove all visible debris or organic material
  2. Apply detergent / degreasing agent and leave for 15 minutes (or longer according to label instructions)
  3. Rinse off with clean water
  4. Apply appropriate disinfectant at recommended concentration and leave to penetrate for the period recommended by the manufacturer
  5. Rinse with clean water

It should be noted that disinfectant solutions need to be replaced before they lose efficacy. To avoid this happening, the date of disposal should be clearly displayed on the solution once it has been prepared.

All products used for disinfection must be used and disposed of in accordance with the manufacturers’ recommendations and likewise any health and safety guidelines should also be closely adhered to. If a Material Safety Data Sheet (MSDS) has not been supplied with the product we strongly recommend that a MSDS be obtained from the manufacturers’ website or from the suppliers of the product.

NOTE FOR SHELLFISH OPERATORS: There is currently no published information regarding disinfectants suitable for use specifically against mollusc pathogens such as Oyster Herpes Virus (OsHV1-uvar) and V. aesturianus. However the combination of a heavy duty detergent such as Biosolve and a broad spectrum disinfectant such as Virkon is suggested.

The table below contains information on the range of disinfectants suitable for use in finfish aquaculture sites in Ireland.

Disinfectant/Cleaner    Example*    Dose     Comments
Chloramine T                 Halamid  1% (w/v), 5 mins Reported effective against ISAv (1% for 30 minutes vs. IPNv)  




100ppm, 10 mins Reported to be effective against ISAv and IPNv. Loss of brown colour indicates loss of efficacy. Iodine requires neutralisation before discharge. Stains and is corrosive.
Peroxy Compounds

Virkon Aquatic


1% (w/v), 10 mins (IPNv)0.5% (w/v), 30 mins (ISAv)

Reported to be effective against fish pathogenic bacteria and viruses (BKD, furunculosis, ERM, ISA, IPN, rhabdoviruses).
Calcium oxide (quicklime)   0.5kg/m(sq)  for 4 weeks      Can be used for earthen ponds (dried). Dangerous substance.
Chlorine Dioxide Cidox  1-1.5ppm CIO2  Can be used for water treatment for processing plants.
Citric Acid   2g/l (0.2%) (w/v) for 30 mins  Can be used to disinfect clothing.
Hydrogen peroxide Hyperox  1:100 (1%), 30 min  Reported  to be effective vs ISAv.
Sodium hypochlorite  

100ppm, 10 mins (a)

1000ppm, 10 mins (b)

1000ppm, 6 hours (c)

Used for:

(a) Boats, cages, tanks, hand nets, harvest equipment

(b) Processing plant effluent

(c) Cage nets

Leave to inactivate for a few days or neutralise with sodium thiosulphate after three hours. Not effective if organic material present.

Sodium hydroxide

Biosolve Plus


1:100 (1%), 500mls/m(sq)

1:250, 15 mins

Used for degreasing and cleaning of well boats, work boats, equipment, processing equipment & utensils.

122mj/cm(sq)/sec (IPNv)

290mj/cm(sq)/sec (noda)

Used on freshwater intake.

Efficacy compromised by organic loading.

May be combined with ozone for treating processing effluent.


70 (deg) C, 2 hrs - IPNv

60 (deg) C, 2 mins - ISAv

37 (deg)C, 4 days -  noda

Used on nets, diving gear.
Formic acid             Used for ensiling.
Ozone   8mg/l/min, 3 mins (redox 600-750mV) 

Used on water intake and effluent

Costly and toxic to fish and humans

Peracetic acid, hydrogen peroxide and acetic acid mix 



0.4% (v/v), 5 mins  Reported to be effective against ISAv.

*The inclusion or exclusion of a particular brand on this list does not indicate an endorsement or a rejection of its use by the Marine Institute


More detailed information on the disinfection of aquaculture establishments and equipment can be found in the World Organisation for Animal Health's (WOAH) Aquatic Animal Health Code in Chapter 4.4.


If you have a particular query relating to disinfectants, please contact the Fish Health Unit at the Marine Institute on 091 387200 or email