The report by the consumer watchdog found that almost half of the 14 laundry, toilet cleaner and nappy brands surveyed made environmental claims that could not be supported convincingly.
All the toilet cleaners in the report including Tesco’s Naturally brand and Sainsbury’s Cleanhome brand, Ecover and Green Force cleaners were criticised for making unproven claims.
Tesco’s Naturally toilet cleaner claims that it contains no phosphates and leaves no hazardous chemical residues, but non-eco cleaners do not either.
Which? says Tesco has agreed to change its packaging as a result of the report.
Ariel and Persil laundry detergents both carry a logo that implies the products encourage greener behaviour but the report found that it was unclear what environmental issues it relates to.
John Twitchen, who runs green communications agency Sauce Consultancy, says: “Products targeting green consumers have a responsibility to be clear and unambiguous; while claims may be scientifically proven, the evidence has to be accessible to the average consumer.”