Chetwin said four of the companies, including Coola, provided lab reports showing their products had been tested and met their label claims.
However, two reports dated from 2015 and Coola's report was from 2013. In response to Consumer NZ's findings, Coola is commissioning a review of its formula.
"There's no requirement for sunscreen manufacturers to regularly test. But that's what they should be doing to ensure their products continue to provide the protection claimed," Chetwin said.
In its 2017 round of testing, Consumer NZ found only nine of 20 sunscreens met their SPF label claims and requirements for broad-spectrum protection.
Chetwin said the lack of a mandatory standard meant sunscreens could be sold without undergoing any testing.
"New Zealand has one of the highest rates of skin cancer and melanoma in the world but the sunscreen standard remains voluntary," she said.
Companies don't always agree with the findings of Consumer NZ's annual study.
This year, Johnson & Johnson sent a statement saying that it stood by its product included in the rundown from Consumer NZ.
While Consumer NZ found that 'Neutrogena Ultra Sheer Face & Body Dry-Touch Sunscreen Lotion (SPF50)' provided an SPF of only 42, a spokesperson from the company said its products have been tested extensively.
"We stand confidently by the label claim of SPF50 on the Neutrogena Ultra Sheer Face & Body Dry-Touch Sunscreen Lotion SPF50," the statement said.
"This claim is substantiated by independent test results conducted on this product formulation by a highly qualified, experienced and credible research laboratory that meets our rigorous standards."
This isn't the first time Johnson & Johnson has raised questions about the Consumer NZ's tests.
Consumer NZ notes that in December 2017 Johnson & Johnson signed court-enforceable undertakings that its sunscreens would meet the voluntary standard, after previous testing found the company's Neutrogena Sensitive Skin SPF60+ failed to provide the high protection it claimed*.
Subsequent testing by the Commerce Commission found this cream didn't meet the claim.
The company voluntarily withdrew that sunscreen in September 2016.
Products that did meet claims:
• Nivea Sun Kids Protect & Sensitive Sun Lotion SPF50+ ($7.50 per 100ml)
• UV Guard Max Sunscreen SPF50+ ($12.00)
• Essone Natural Sunscreen Summer Coconut & Jojoba SPF30 ($51.30)
Close but not quite:
• Smart365 Sun Sunscreen Lotion Kids SPF50+ - Met the high protection claim, but failed one of the broad-spectrum requirements
• Neutrogena Ultra Sheer Face & Body Dry-Touch Sunscreen Lotion (SPF50) - testing revealed an SPF of 42
Products with contradictory results:
• Beauty Care Co Sunscreen Lotion SPF50+
• Bondi Sands Coconut Beach Sunscreen Lotion SPF50+,
• Banana Boat SunComfort SPF50+
• Sunsense Sensitive Invisible SPF50+
• Coola Classic Body Plumeria SPF30
For more information on the methodolgy, see the full Consumer NZ report.
*Correction: Neutrogena Sensitive Skin SPF60+ was previously included in this story as one of the products tested by Consumer NZ this year. It was, in fact, tested in a previous year. This has been corrected.