Earthwise dishwashing powder is being recalled after tests revealed it was highly corrosive and failed to comply with the required safety standard.
The tests showed the powder had a PH of 13.2, compared with a safety standard requiring a PH of no more than 12.5.
Consumer New Zealand, which tested it, says it was advertised as naturally powerful and naturally kind.
Chief executive Sue Chetwin says there have been cases of children suffering severe mouth burns after ingesting powders with a high PH, with some requiring multiple surgery to deal with the burns.
Ms Chetwin says the company has since changed its blending method, but concerns remain that a powder was being sold with such a high PH, meaning it is highly alkaline.
Earthwise director Allen Peters says there was a problem with the way the ingredients were being mixed and the faulty batch has been completely removed from supermarket shelves.
A statement released on the Earthwise website apologises and offers customers a refund on the recalled batch.
The powder was the only product that failed the safety test, out of 19 dishwasher detergents.