LEGIONELLA - 21.11.2014

How to clean your showers

What is the danger?

Legionnaires’ disease is a potentially fatal illness caused by inhaling legionella bacteria within fine droplets of water. Showers and spray taps are particularly risky as: (1) there is a large surface area for the bacteria to breed; (2) the intricate parts of the shower head encourage the build up of scale and slime; (3) the hose is normally left full of warm water after it has been used; (4) showers may not be run for several days or weeks; and (5)  the shower head creates fine droplets which can be inhaled. If you were looking to design a system to develop and distribute legionella bacteria, you couldn’t do much better than a shower.

Flushed

To comply with the Control of Substances Hazardous to Health Regulations 2002 , you must ensure that your workplace shower is run regularly and cleaned periodically. These standard practices are described within the HSE’s guidance document Legionnaires’ disease part two: The control of legionella bacteria in hot and cold water (ref HSG274) (see The next step ).

Tip 1. As a rule, if your shower is used less than once a week, make sure that it’s flushed through. Take off the head and run for several minutes. Keep a record of this (see The next step ).

Tip 2. If you have a shower no longer in use, consider removing it rather than regular flushing and cleaning. Take the pipework back as far as possible to limit the length of “dead legs” in the system, a major breeding ground for legionella bacteria.

Keep it clean

The HSE’s guidance HSG274 advises that when cleaning showers and similar devices you must, “dismantle, clean and descale removable parts, heads, inserts and hoses where fitted”. This must be carried out, “quarterly or as indicated by the rate of fouling or other risk factors, e.g. areas with high risk patients”.

A typical cleaning process involves six steps: (1)  disassemble the shower head and hose; (2)  place in a bucket with descaler; (3) rinse with fresh water; (4) soak in disinfectant; (5) rinse with fresh water and reassemble; and (6) record that the cleaning process has been carried out (see The next step ).

Tip 1. Chlorine-based disinfectant products are commonly used to disinfect, e.g. tablets used to sterilise infants’ bottles. If in doubt contact the manufacturer to check effectiveness against legionella, and for the dilution rate and timing.

Tip 2. You may find that the surface finish of your shower head is vulnerable to damage, e.g. if it has a chrome effect. If that’s the case, you’ll need to replace it with something more robust. Preventing Legionnaires’ disease is a higher priority than scrimping on the cost of a new shower head.

Tip 3. Have some spare washers available as leaks may emerge on reassembly. Neoprene or other rubber substitute materials are best as they are less likely to harbour bacteria.

For a link to HSG274 part two, a record of dead legs and infrequently used outlets and a shower cleaning record, visit http://tipsandadvice-healthandsafety.co.uk/download (HS 13.06.06).