Cleaning Without Chemicals

Cleaning Without Chemicals

Cleaning is often portrayed as a battle against dirt with “chemicals” as the weapon, and mops and cloths as tools to wage war. Of course, this is being somewhat melodramatic, but chemicals and equipment (mops and cloths) form a combined team in remarkably complex chemistry. Before we look at cleaning without chemicals, we need to appreciate how chemicals and equipment work together. We will limit the term “chemicals” to just detergents, not including acids as their mode of action is different; acids chemically react with scale deposits and proteins. But we need to include the use of steam and similar equipment that are designed to deliver dry or wet steam above the boiling point of water – this is critical for the disinfection of surfaces.

Surfactants in Detergents

A cleaning detergent product is a precise mixture of a number of component parts – each with a precise function – that work in conjunction with water as a solvent. Because most soilings or dirt is oily in nature and therefore insoluble in water, the main component in a detergent, the surfactant, assists in making the insoluble soiling soluble in water.

This is mechanism can be summarised as follows:

surfactant-at-work

Surfactant molecules are depicted as:

surfactant

 

 

 

 

Part A shows free-floating surfactant molecules in water, covering an oily deposit on a solid surface.

Part B shows that the surfactant molecules orientate themselves at the interface between the oily soiling and water. The “tails” adsorb onto oil and the “heads”, being charged, face towards the water. This creates a reduction in the surface tension at the interface, allowing the oils to be broken up into smaller pieces (Part C) through the mechanical action of the cloth or mop – the physical process of cleaning.

This leads onto to Part D, where the surfactant molecules completely encapsulate microscopic droplets of oil within the water. Because of this encapsulation, called micellisation, the “heads” repel other “heads” from other micelles and from surfaces, therefore the oily soiling doesn’t redeposit.

I know this is very basic, but it is adequate to demonstrate the chemistry behind detergents. What you will notice though is where and why the physical mechanical action is necessary to aid the detergent action. Without any form of mechanical action, which must be stressed that it can include any form of fluid motion and rapid changes in viscosity of the oils through heat, the mechanism is likely stop at Part B. One of the interesting aspects of steamers, and to a greater extent hot pressure washers, is that the heat dramatically reduces the viscosity of oils and greases and at the same time provides the mechanical action from the fluid motion.

Cleaning without chemicals

As we have seen, chemicals in the cleaning process play a very important role, and in concert with the physical action of cleaning equipment. However, in recent years, textile technology has greatly advanced in aiding the removal of soiling from a surface through lyophilic materials (oil-attracting materials) in conjunction with complex structured fabrics. This allows the user to adopt milder detergent mixtures, that are both kinder to the skin and to the environment. But you still need chemicals to prevent re-deposition of the soiling on to the surfaces and to provide biocidal effects.

Microfibre

This technology has also developed a range of fabrics called microfibres; there is a further discussion on microfibres and their properties here. Their unique properties allows light to medium duty cleaning on non-porous surfaces using just a sprinkling of plain water – cleaning without chemicals. It does have its drawbacks, namely: Generally they are much more expensive, they require greater physical effort, they have to be laundered carefully and the amount of water used for cleaning has to be carefully controlled – too much water and they lose they unique properties.

Microfibre cloths are perfect for light-duty cleaning of small areas of glass or plastic, non-food table tops like desks and computer LCD screens, as long as you don’t press too hard. Microfibre mop heads are marketed for use in hospitals or other medical facilities and are only in composition with traditional materials. This has the effect of making the mop head more absorbent and more aggressive on stubborn soilings, but as a consequence it requires more effort to move across the floor. So it is a compromise and a balance between different fibres, clean-ability and ergonomics. Fortunately, equipment manufacturers are designing their equipment with ergonomics in mind, with some better than others.

The environmental nature of detergents

The stick with which “people” beat the drum of environmental concern in the media often groups detergents in cleaning with other “hazardous” chemicals, whether that is hazardous to the environment or to human health. This is remarkably ignorant to the nature of chemicals and their effect. By all accounts every chemical is a poison to some degree to the environment and to us – even water in sufficient quantities can kill us – and it is quantity that is the key, as the old adage say’s “the poison is in the dose”.

Saying that, in the past there were many cleaning product ingredients that were hazardous, take your pick of the many chlorinated hydrocarbon solvents, also with the expanding field of environmental analysis, many detergent ingredients were found to affect the environment. As a consequence, environmental and safety legislation in western countries have either banned specific compounds or mandated replacements. For example, Nonylphenol ethoxylates (Alkylphenol ethoxylate – APE’s) while safe in use produce estrogen-like byproducts from biodegradation and has been detected in waste-water treatment systems. They have now been banned for use and a good replacement in the form of linear alcohol ethoxylate has proven to be effective.

So it is important to be aware that the environmental standards for cleaning product ingredients are very high, most often the ingredients will biodegrade naturally in a few days and virtually completely in 30 days. EU regulation 648/2004 was updated requiring the ultimate biodegradability of detergents sold to be 90%. This does not apply to biocides, but they come under the new biocide product directive (BPD).

Human Health

Detergents very nature to lift and solubilise oils and greases, has the unfortunate ability to solubilise the skin’s natural oils and greases. We have all felt this effect after a lengthy time hand washing the pots or hand washing the car, our skin feels tight and very dry. If you are a cleaner and you job involves contact with detergents in solution on a daily basis, then you’re particularly liable to develop dermatitis. Adopting sensible measures to reduce the contact can easily taken, gloves are the obvious method, but barrier cream and non-contact cleaning equipment can effectively isolate you.

A typical complaint from the cleaning industry are the over-use of detergents, most often you don’t need a strong or concentrated product, and cleaners tend to under-dilute the detergent making the solution far too concentrated. Learn how to use detergents, the right product and the right method – you will cut down on overly strong and potentially damaging detergents.

Conclusion

The vast majority of common cleaning processes do not require strong detergent products. And a common misconception is that the detergent alone provides the cleaning action. It is possible for cleaning to be done without chemicals, microfibre cloths and mops are a good example, but they do come with their significant disadvantages as discussed here. The way to look at cleaning is a collection of the right tools working together, complimenting each other and adopting sensible protective measures.

Rafael Cobos
rafcobos@futurecleansystems.com