Preventing the spread of bacteria in flooded areas
February 1st 2011

Water in flooded areas contains pathogenic organisms from sewage and other materials.These can present a health risk and care must be taken to avoid direct contact with flood water, associated debris and contaminated surfaces. Protective clothing and gloves should be worn and fresh water used for all cleaning tasks.When this is not possible any available water should be pre-boiled to kill off pathogens that may be present.

Hand and skin cleansing helps reduce the risks associated with handling contaminated water and materials. Skin cleansing can be augmented with an alcohol based hand sanitiser or disinfectant.This is important when the water used is not of drinking quality.A disinfecting hand wipe can also be used.

Food preparation or storage areas that have been in contact with flood water must be cleaned and sanitised. Each area should be cleaned using a sanitising detergent and then disinfected by a repeat use of the sanitiser or disinfectant.The flood water may contain pathogenic organisms that are unaffected by the usual kitchen sanitisers. For these areas, sanitisers that contain a chlorine or oxygen based bleaching system are suitable.Water used for the final disinfection stage should be of drinkable quality.

For dishwashing in areas where boiling of tap water is recommended, the machine should be set to its longest, slowest cycle.All wash and rinse jets should be checked and cleared before washing starts. Running temperatures should be 55-65°C for washing and 80-90°C for final rinse.

For other areas, debris and damaged items should be removed and disposed of safely.Affected surfaces should be cleaned using a sanitising detergent and then disinfected through repeat use of the sanitiser or a terminal disinfectant.Again, a chlorine or oxygen based bleaching system may be more effective than an everyday cleaning product but can also be used for terminal disinfection.Water used for the terminal disinfection stage should be of drinkable quality.

In non-food areas when flooding is less serious or localised, one option is to use Good Sense Breakdown.This product from Diversey can be used diluted as a hard surface cleaner or neat when poured down drains or toilets. Its active ingredients include cleaners and agents that break down organic matter.An additional Odour Neutralising Technology (ONT) ingredient eliminates strong smells rather than masking them with an overpowering perfume.

Sometimes the flood will be localised inside the building and it may be possible to prevent longer term effects by removing the water from the floor quickly.A scrubber drier is suitable for this as it removes dirt, debris and water from the floor mechanically and places it into its built-in collection tank.The water can then be disposed to remove the risk of infection and contamination from the flooded area. Further decontamination may be required.

Another option is Zorba, an absorbent disposable barrier strip from Diversey that can be used to contain and remove localised flooding.

Each 60cm of the strip can absorb up to two litres of water.When saturated, it can be disposed of quickly and without leaking to remove the water from the affected area.

After the areas have been cleaned and sanitised, they should be dried out as soon as possible.This is because damp conditions are favourable for mould and fungal growth that can damage surfaces and generate spores that can cause health problems. If these are observed they should be cleaned off using the sanitisers used for the original cleaning.Chlorine based bleaching agents can damage soft furnishings so for these an oxygen based sanitiser should be used.

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