Biocides

Biocides

The word biocide can frighten some customers, who do not want to risk the environment around their home or business. If used safely following the correct processes according to COSHH the risks around these chemicals can be controlled however. Furthermore, in many cases biocides are sometimes the only effective means to remove organic growth and the discolouration it causes, from a building substrate. Safe use of biocidal chemicals is integral to the softwashing industry. Misuse of these chemicals are what gives softwashing a bad name.

A biocide is legally defined in Europe as “a chemical substance or microorganism intended to destroy, deter, render harmless, or exert a controlling effect on any harmful organism.” In the USA there Environmental Protection Agency (EPA) defines a biocide as “a diverse group of poisonous substances including preservatives, insecticides, disinfectants, and pesticides used for the control of organisms that are harmful to human or animal health or that cause damage to natural or manufactured products”. These definitions are broadly similar. 

In the softwashing industry two biocides are used in the main. A third organic solution is also available and gaining popularity. These substances are sodium hypochlorite (also known as bleach). Didecyl Dimethyl Ammonium Chloride, more commonly referred to as DDAC. The ‘organic’ Safewash solution is also available.

DDAC

Didecyldimethylammonium chloride (DDAC) is an antiseptic disinfectant that is widely used, in both interior and exterior settings. It works by disrupting the fatty lipid layers that bacteria and fungus use as their ‘body’. It therefore kills fungus and bacteria at the root system. It is used extensively in medical environments. It is used to sterilise hospitals, and also surgical equipment and instruments used in disciplines like gynaecology.  It is also used to clean and treat external surfaces. It will kill all bacteria and on an external substrate, and penetrate porous surfaces to give a residual cleaning effect. It will not however remove black staining from a building immediately.

There are several good quality DDAC based biocides on the market. The most widely used and recommended include Softwash Solutions, Algoclear, and  Bio Cleanze.

Sodium Hypochlorite

In short sodium hypochlorite is bleach. But do not be mistaken. In order for bleach to be used safely and effectively in softwashing it must be chemically pure, so that the correct safe dilution levels can be obtained. If not risk cannot be managed effectively when using the substance- and it can be applied at ineffective, or unsafe, levels. It is vital this hazardous substance is used correctly, as not only can it pose a risk to human and animal health, it can adversely affect the environment and water supplies. There is alo a risk of it breaking down into an even more hazardous byproduct- like chlorine gas, which has been used, literally, as a chemical weapon.

Due to the stringent testing and labelling requirements that allow Sodium Hypochlorite to be used effectively and safely for Softwashing there is only one fully government approved sodium hypochlorite biocide available legally in the UK and Ireland. This is Lightning Cleanze. More info on this product is below. 

Needless to say- the illegal use of swimming pool, household, and dairy bleach for softwashing creates unnecessary risk, and therefore damages the reputation and perception of the softwashing industry.  

Lightning Cleanze 

Unlike other bleach based products Lightning Cleanze will biodegrade totally and not bioaccumulate. It will not therefore leave behind salts that can pose a risk. “After use it quickly breaks down into tiny amounts of ordinary salt and water containing no free chlorine.” While conforming to the Global Harmonised System (GHS) for product labelling it is licensed for softwashing use in the EU, UK, and Ireland. It is “fully compliant with the EU “REACH” (Registration, Evaluation, Authorisation & restriction of CHemicals) regulations for cleaning exterior hard surfaces.”

HSE approval number: 10161

PCS number: 98411

The main benefit of Lightning Cleanze is that it works immediately- giving same days results- and all kinds of staining caused by organic growth. DDAC based products cannot remove blacvk staining the same day (although weathering will remove some blacks stains in the weeks after a DDAC application). If you have black staining on your property, and expect same day results, then a softwasher must use Lightning Cleanze- if not they are most likely working illegally and unsafely.

If you know Lightning Cleanze is being used on your property then insist that the contractor rinses after application. It takes a  maximum of 60 minutes for the full effects of Lightning Cleanze to become apparent. After which rising removes the trace amounts of salt that are left behind. This cleans ‘the pores’ of a building substrate- and deters the regrowth of organic contaminants. 

Lightning Cleanze is only shipped in the UK and Ireland.

Safewash

Safewash is a cleaning product derived entirely from orange citrus fruits. It has a biocidal action that kills red and green algae, and removes the green staining from buildings. It is otherwise safe for the environment, and therefore the lowest risk way to softwash a building. It will not remove black staining.

More information on the product can be found here, and here.

If conforming to best practice according to the hierarchy of risk then Safewash is essential. Similarly- if you wish your project to have the minimum environmental impact the product is vital. It does tend to be more expensive than alternatives however, due the quantities required, and associated manufacturing costs.