This blog was written by Thames Valley Specialist Products Limited.

Specific guidance is difficult to find and product references made on marine guidance sources are out of date or refer to pond chemicals.

Whatever you have heard or words of wisdom received in the past, a marine licence is not required from the Marine Management Organisation (MMO) for cleaning slipways — what needs to be understood is that any biocidal product containing active substances, with the intention of destroying algae, is required to have Health and Safety Executive (HSE) approval.

The HSE does not have a marine biocide classification and the Harbour Master has to rely on commercial information to make a choice.

Products based on sodium hypochlorite, even diluted down to their minimum limit of efficacy leave an environmental footprint in that resulting halogen compounds have a long life.

A chemical without an environmental footprint is ideally needed and this leaves those responsible with very few choices. Among them are hydrogen peroxide and some quaternary ammoniums.

Hydrogen peroxide evaporates without a trace but can be dangerous to spray at the required diluted concentration without caution, (Safer when applied in gel form). What is needed is a product whose active ingredient breaks down in contact with sea salt and is effective between tides.

Algoclear Pro is a quaternary ammonium concentrate of Didecyl Dimethyl Ammonium Chloride (DDAC) . The product is high purity and suitable for the treatment of algae in tidal Areas (HSE registration №8832).

DDAC works at a cellular level. The DDAC molecule has a positively charged (cationic) head. The cell wall of algae being negatively charged (anionic), like a magnet is attracted to metals, DDAC contact results in a breakdown of the cell wall and loss of vital functions of algae. In the process the molecule of active ingredient is depleted and broken down so, applied at an optimum dosage for the amount of live biomass present, works predictably every time.

The molecule has no oxidizing property or other chemical activity and is fundamentally safe in use. We also gain help from nature as any unused molecules of the active ingredient immediately break down when in contact with sodium chloride, salt.

In application Algoclear Pro foams. It has natural surfactant properties and will remove oil and grime. The surfactant effects disappear as the salt deactivates the molecule.

In other amenity maintenance Algoclear Pro is used for all hard surfaces from cleaning and disinfecting artificial sport surfaces, children’s play areas, timber decking (it’s also classified as a wood preserver), polytunnels and Glasshouses and rendered and painted surfaces. A note of warning, Algoclear Pro should not be used to clean pontoon decking over fresh water in lakes or rivers.

Final note: Whatever you choose to use avoid products containing sodium hypochlorite (bleach) or copper sulphate and always check with HSE that licences numbers exist and are current