Buying and using concentrated cleaning products which are then diluted at the point of use has big potential sustainability benefits:
- Because the water is only added when needed, it doesn’t need to be packaged, stored or transported. The savings in packaging by refilling trigger sprays from concentrate, rather than throwing them away when empty, can be huge: a single 5 litre container of concentrate can save the plastic and the energy that goes into making around 500 typical 750ml trigger bottles, and then transporting over a third of a ton of water around the country.
- When buying concentrates for dilution, larger packs again save packaging. A 2 litre bottle uses only two thirds of the packaging per litre compared to a 1 litre bottle, and a 5 litre pack uses only about one third.
The more concentrated the product of course, the more vital it is to have good dilution control to avoid waste which is costly environmentally in terms of resource consumption as well as costly economically.
While the above advantages are clear, practical considerations and the economic and social dimensions of sustainability can sometimes cancel out these benefits, especially for small-scale cleaning, such that diluted ready-to-use products make the most sense. Cleaning operations need to be considered case by case. The table below lists some important factors which influence the overall sustainability of concentrates, with different approaches to dilution control, in social and economic as well as environmental terms. The five approaches compared are:
- Standard concentrate products diluted manually
- Ready-to-use products
- Super-concentrates with portion control – adding a known amount of product to a known amount of water
- Super-concentrates in dilution control – systems where the chemical and water is automatically mixed
- Super-concentrates in closed-loop, dilution control – as above but the user cannot gain access to the neat product
Sustainability pros and cons of different concentrates and dosing systems
In the chart, a ‘0’ represents “average”, ‘+’ means “better” and ‘-‘ means “worse than average.
|Standard Concentrate Manual dosing||Ready to Use||Superconcentrate with Portion Control||Superconcentrate with Dilution Control||Superconcentrate with Closed Loop Dilution Control|
|Ease of Training||0||+||0||+||+|
|Productivity / Re-work||–||+||–||+||+|
|ECONOMIC||Price per litre ‘neat’||0||–||–||–||–|
|Price per litre in use||+||–||+||+||+|
|ENVIRONMENTAL||Transport / Storage||0||–||+||+||+|
|Env. Hazard ‘neat’||0||+||–||–||+|
The comparison is largely qualitative and represents only a generalized position: it does not consider constraints which attach to specific products, or the relative importance of each factor (which will vary from one cleaning task to another) or the extent of the improvement / shortcoming. Nevertheless, because the systems towards the right have many positives and few negatives they will often tend to offer the most sustainable approach. Where organisations can easily gear their organisation and logistics to use these more advanced approaches, there are big gains to be made. But there surely are situations where the constraints and relative importance of the different factors is such that ready-to-use products or manual dosing of standard concentrates are still the most sustainable and prudent choice in practical terms.