Our 2012 test of dishwasher detergents found a highly corrosive "green" dishwasher powder.
Earthwise Dishwasher Powder was advertised as "naturally powerful and naturally kind". But our test of this product found it highly corrosive and failed to comply with a safety standard for hazardous substances. After we advised the manufacturer of the results, it withdrew the product from shop shelves.
Testing showed the Earthwise Dishwasher Powder we bought had a pH of 13.2, a level which is regarded as highly corrosive. Since 2007, the Cleaning Products (Corrosive) Group Standard has prohibited sales to the public of automatic dishwasher detergents with a pH higher than 12.5.
We've previously reported on cases where children have suffered severe burns to the mouth, throat and airways after eating dishwasher powders with a high pH. Some of these burns were so severe the children required numerous operations to repair damage caused by scar tissue.
18 of the products in our 2012 test had a pH below 12.5, complying with the pH standard. We have regularly included pH testing in our dishwasher detergent tests since 2015 and no products have recorded a pH above 12.5.
Marketing claims made for this powder may also breach the Fair Trading Act as well as separate rules for advertising hazardous products. These rules prohibit false or misleading representations about the safety of a substance. We think claims the powder is "naturally kind" give the impression it's a safer choice. With a pH of 13.2, that's not the case.
After we reported our results to Earthwise, the company said it had investigated and found variations in pH within the same batch. It subsequently advised that no further automatic dishwasher powder was distributed and existing product was withdrawn from shop shelves. A public recall was issued on 23 August 2012.
Automatic dishwasher detergents often contain corrosive alkaline salts and need to be used with care. These substances can cause chemical burns if eaten, left on the skin or if they get into your eyes.
Detergents and cleaners are among the most common causes of inquiries to the centre about child exposures to hazardous substances.
All the products we bought had safety warnings and first-aid information on the packaging. However, this was usually in smaller print on the back of the container. None had a warning on the front. We also found first-aid information varied widely between products.
The National Poisons Centre's Lucy Shieffelbien says there's no harmonisation of first-aid advice. "Ideally, we would like to see manufacturers use the same advice that we give. Some manufacturers are very good and will actively seek our advice but most don’t," she says.
Child-resistant packaging reduces the risk of children coming into contact with dishwasher detergent. However, no container is 100 percent "child proof". The Cleaning Products (Corrosive) Group Standard defines packaging as child resistant if 80 percent of children aged around 4 years would be unable to gain access to the contents, or would be unlikely to obtain a toxic dose within 5 minutes.
Regardless of the packaging, dishwasher detergents need to be stored well out of the reach of children or in a locked cupboard. This includes dishwasher tablets. These tablets could be confused with sweets and shouldn't be left where children can get them.
To reduce the risk of accidental exposure, only put detergent in the dishwasher when you're ready to start a wash. Make sure any residue is removed from the dispenser afterwards and close the door firmly. Burn injuries have occurred when children have swallowed detergent left in the dispenser.
Our 2012 test
We tested 19 automatic dishwashing powders and tablets for pH.
Testing was carried out for Consumer by Environmental Science and Research and funded by the Ministry of Health. pH levels were approximated by indicator paper and then measured by a calibrated pH meter.
The pH value measures how acidic or alkaline a substance is on a scale of 0 to 14. A pH of 7 is neutral. A pH below 2 or above 12 is considered highly corrosive. Each pH value above 7 is 10 times more alkaline than the next lower whole value. For example, a pH of 10 is 10 times more alkaline than a pH of 9.
Test results table
|pH less than 12.5|
|Active Automatic Dishwashing Powder Lemon|
|Active Automatic Dishwashing Tablets Lime with Baking Soda|
|Earthwise Dishwasher Tablets Lemon & Lime|
|Ecostore Auto Dish Powder Lemon|
|Ecostore Auto Dishwash Tablets Fragrance Free|
|Finish Classic Powerball (parallel import) (A)|
|Finish Power Powder Lemon Sparkle|
|Finish Power Powder Orange|
|Finish Power Powder Regular|
|Finish Powerball Lemon|
|Morning Fresh Super Concentrate Tabs Lemon Fresh|
|Next Generation Auto Powder Citrus|
|Next Generation Citrus Dishwashing Tablets (mini tablets)|
|Shotz Dishwasher Powder (A)|
|Shotz Dishwasher Tablets (A)|
|Sun Dishwasher Powder Sunshine Lemon (B)|
|Woolworths Homebrand Dishwasher Tablets|
|Woolworths Select Dishwasher Tablets Lemon Scented|
|pH greater than 12.5|
|Earthwise Dishwasher Powder Lemon & Lime|
Guide to the table
Products were tested for compliance with the Cleaning Products (Corrosive) Group Standard which prohibits the sale of solid automatic dishwashing preparations that have a pH of more than 12.5 (as measured in a 500g/litre aqueous solution or mixture).
All products were purchased at supermarkets unless otherwise indicated.
A = bought from The Warehouse.
B = bought from Mitre 10.
- We're extremely concerned that Earthwise Dishwasher Powder failed to meet the pH standard. This standard was introduced in 2007 and manufacturers have no excuse for not complying with it.
- Automatic dishwasher detergents need to be used with care. Make sure you store detergents and other cleaning products securely, out of reach of children or in a locked cupboard.