It may be time to rethink the sunscreen you slap on as Summer approaches, after nine out 20 products did not meet their label claims in Consumer NZ's latest test.

A Cancer Society Sunscreen SPF50+ was among those that didn't make the cut, after it was found to provide a maximum SPF 20 units less than it claimed to, when tested at two different labs.

The Cancer Society said it would withdraw the batch of the product tested as a result of the findings, Consumer NZ chief executive Sue Chetwin said.

"However, given the reports we have from two separate labs showing the sunscreen doesn't measure up to its claimed performance, we've asked it to recall all batches of this product."

A sunscreen had to achieve SPF60 in lab tests to claim SPF50+, she said.

Several other big-name brands that failed their SPF50+ claim included Sunsense Ultra, Banana Boat Dry Balance Sunscreen Lotion and Marine Blue Australia Dry Touch Sunscreen Lotion.

These sunscreens provided considerably less protection than they claimed, with their SPF protection ranging between 20.61 and 26.4, only providing moderate protection.

Five other products also provided less SPF than they claimed to on the label, but still provided high protection of SPF30 or above.

Three sunscreens didn't provide the broad-spectrum sun protection claimed, the survey found.

The products tested in this year's survey fared better than those tested in 2018, when only four of the 19 sunscreens tested met their SPF label claims and requirements for broad-spectrum protection.

Chetwin said the Cancer Society and Sunsense were among the companies that tested their products at AMA Laboratories, a sunscreen testing facility in the US.

AMA's owner was charged with, and some staff pleaded guilty to, falsifying test results from 1987 to April 2017, the US Food and Drug Administration announced in August this year.

The Cancer Society's test report for its product was from this year, while Sunsense's dating back to 2016.

"For many years, sunscreen companies have been sending us test results from AMA that conflicted with our tests. We think companies relying on these results should urgently re-test at a different lab to ensure they can back up claims," Chetwin said.

The Cancer Society said it was voluntarily withdrawing a batch of its sunscreens as a result of the Consumer NZ tests differing from its own.

"We would have preferred to retest the batch to prove its effectiveness, however that would take eight weeks so we've made the call to voluntarily withdraw the batch from retailers now," Mike Kernaghan, chief executive of Cancer Society NZ, said.

"We remain 100 per cent confident in the effectiveness of our sunscreen products because they are manufactured as a medicine in Australia and have been independently tested.

I would like to reassure the public there is no health risk, because even at the lower level of SPF30 that batch still provides high protection."

The Cancer Society said it had its full sunscreen range independently tested at an Food and Drug Administration-approved, ISO registered laboratory this year.

The results show all products exceed their SPF claims. However, for the product batch being withdrawn (Everyday Very High Protection Sun Lotion SPF50+ with Expiry Oct 2021), Consumer NZ's results were significantly different, the society said.

Consumer NZ's Chetwin called on the Government to urgently regulate sunscreens.

"New Zealand has one of the highest rates of skin cancer and melanoma in the world but the sunscreen standard remains voluntary."

In April this year, Consumer NZ made a submission to the Ministry of Health supporting sunscreens being required to comply with the Australian and New Zealand standard.

The organisation has also asked for regulations to specify how often sunscreens must be tested and include minimum requirements for test labs.

HOW THE SUNSCREENS FARED

FAILED TO MEET SPF LABEL CLAIM

• Hawaiian Tropic Silk Hydration Sunscreen Lotion SPF50+ A Touch of Mango and Papaya

• Invisible Zinc Face + Body Mineral Sunscreen SPF50

• Natio Suncare Moisturising Sun Lotion SPF50+

• Frankie Apothecary Natural Sunscreen + Kawakawa and Antioxidant SPF50

• MooGoo Natural Sunscreen SPF40

• Cancer Society Everyday Sun Lotion SPF50+

• Marine Blue Australia Dry Touch Sunscreen Lotion SPF50+

• Sunsense Ultra SPF50+

• Banana Boat Dry Balance Sunscreen Lotion SPF50+

MET SPF CLAIM BUT FAILED BROAD SPECTRUM PROTECTION REQUIREMENTS
• Beauty Care Co Zinc Sport Sunscreen Lotion SPF50+
• Surf Life Saving Suncreeen Lotion Dry Touch Formula SPF50
• Wotnot Deeply Moisturising Sunscreen SPF30

MET SPF CLAIM & BROAD SPECTRUM PROTECTION REQUIREMENTS
• La Roche-Posay Anthelios XL Ultra-Light Fluid SPF50+
• Neutrogena Ultra Sheer Dry-Touch Sunscreen Lotion SPF50+
• Nivea Sun Protect & Moisture Moisturising Sunscreen Lotion SPF50+
• Smart365 Sun Sunscreen Lotion SPF50+
• Oasis Sun Sport PA++++ SPF40
• Badger Sport Unscented Natural Mineral Sunscreen Cream SPF35
• My Sunshine Natural Sunscreen + Antioxidants SPF30
• Solzinc Natural Sun Protection 30+