Lanfax Labs in association with Choice tested 49 powder detergent concentrates in early 2007, resulting in "Wash Only" data for 35 powders in front loaders and 35 powders in top loaders. The report was published in "Choice" in the April edition. The data below extend to dual testing of products where one brand was suitable for both front and top loader. These data are presented independently of "Choice".
pH
pH of the powders was measured in a fresh sample of detergent mixed with the equivalent of rainwater at the rate for the "wash only" cycle. The longer the bar, the higher the pH (more alkaline). High pH may cause some plant nutrients to become less available, others more available, leads to the dissolution of organic material and induce dispersion in the soil to which the washing water is discharged. pH levels of wastewater outside the range of 5-9 may be detrimental to the environment. See discussion of pH under main heading
Graph 101. pH of "wash" only water when dosed at the recommended rate for front load or top loader. The pH of the clean water input will have a slight effect upon the final pH. The values below have been from a source using rainwater. All these products are highly alkaline and well outside the range at which normal biological activity is expected to perform. They are "hazardous" products and cannot be labelled "environmentally friendly", quite the opposite.
Of great importance is the rinse performance of the washing machine is removing the residual detergent from the clothes so that, at some later stage, these chemical do not react with your skin to irrigate and cause discomfort or a rash. As the Australian Standard test for rinse performance is not done with a "real" detergent at the various doses for the different brands, it is my opinion that the Standard fails to adequately protect the consumer. A machine that adequately washes a dose of 20 g per wash, may be totally ineffective in washing 120 g per wash. As the recent Choice results indicate, the were the worse performers when both the wash and rinse were averaged (see analysis under "washing machines".
Figure 101C shows that there are only a few products that have low pH and the majority have pH above 10.4. There are more front loader detergents with very high pH than detergents mixed for top loaders. BE AWARE - very high pH liquids should not be spread over leaves or stems of plants. If you are unsure of the response of your plants, experiment a few that you can afford to lose.
In many cases it is not the sodium or the phosphorus in detergents that is damaging, but the very high pH/ High pH detergents can remove the protective coating over leaves and plant stems and leave the plants susceptible to disease and insect attach.
