More sunscreens have been removed from sale after Australia’s drug regulator warned they were unlikely to meet their sun protection claims, with some possibly having an SPF as low as four.

The advice follows recent testing by Choice in which the worst offender was Ultra Violette’s Lean Screen, which claimed an SPF 50+  but was actually only four.

It was pulled from the shelves after the company did further testing.

The Therapeutic Goods Administration said this week that Lean Screen was manufactured using the same base formulation as several other sunscreens.

Preliminary SPF testing results by the maker of the base formulation, Wild Child Laboratories, has now shown it is unlikely to have an SPF greater than 21.

“Preliminary testing of specific goods manufactured using the base formulation indicate that the SPF value of the goods may, for at least some of the goods, be as low as SPF 4,” the TGA said, adding that Wild Child had stopped making and supplying the base.

Some of the 21 sunscreens made using the base formulation (see full list below and here) have been recalled voluntarily, including Advanced Skin Technology’s Aspect Sun SPF50+ Physical Sun Protection and Tinted Physical Sun Protection.

Others – including several Ethical Zinc and Endota-branded sunscreens – have paused supply while the product is under review.

Results shared by Ultra Violette from tests on Lean Screen.

The TGA said that as part of its investigations into SPF sunscreen testing, it had found “some testing laboratories may be more reliable than others”.

“In particular, the TGA has significant concerns about the reliability of SPF testing undertaken by Princeton Consumer Research Corp (PCR Corp), a testing laboratory based in the United Kingdom,” it said.

“The TGA is aware that many companies responsible for sunscreens manufactured using this base formulation relied on testing by PCR Corp to support their SPF claims, and that they obtained that testing before they were informed of the TGA’s concerns.”

Only four of the 20 popular sunscreens originally tested by Choice met their SPF 50 or 50+ claims. Those that didn’t included products by the Cancer Council, Banana Boat, Neutrogena, Woolworths, Bondi Sands and Aldi.

Although the consumer group said the tests were carried out by experts in a specialised, accredited sunscreen lab, the results were disputed by some of the brands.

Choice CEO Ashley de Silva said it was “highly concerning” to see the TGA confirm that sunscreens using the same base formula as Ultra Violette’s Lean Screen were unlikely to meet their SPF claims.

“If you’re currently using one of the sunscreens that shares this base formula, the TGA is advising you to consider trying out a different product as we head into hotter months,” de Silva said.

“If you’ve been burnt while using one of these products – or any sunscreen – consider reporting your experience to the TGA.”

An ABC investigation found that eight of the sunscreens that failed the Choice tests had their original SPF certification conducted at the Princeton Consumer Research lab. The TGA said it had written to the company about its concerns but had not received a response.

Wild Child said it had stopped using PCR and had “initiated confirmatory testing with other accredited, independent laboratories to validate the SPF performance of our products”.

It also said the discrepancies reported in recent testing were part of a “broader industry-wide issue” and highlighted the “well-recognised limitations of in vivo SPF testing methods”.

Sunscreens TGA says have with the same base formula as Lean Screen:

• Aspect Sun SPF50+ Physical Sun Protection
• Aspect Sun SPF50+ Tinted Physical Sun Protection
• Aesthetics Rx Ultra Protection Sunscreen Cream
• New Day Skin Good Vibes Sunscreen SPF50+
• New Day Skin Happy Days Sunscreen SPF50+
• Allganics Light Sunscreen SPF50+
• Beauti-FLTR Lustre Mineral SPF50+
• Found My Skin SPF 50+ Tinted Face/Body Cream
• Ethical Zinc Daily Wear Light Sunscreen
• Ethical Zinc Daily Wear Tinted Facial Sunscreen (Dark)
• Ethical Zinc Daily Wear Tinted Facial Sunscreen (Light)
• Endota Mineral Protect SPF50 Sunscreen
• We are Feel Good Inc Mineral Sunscreen SPF50+
• GlindaWand The Fountain of Youth Environmental Defence Cream SPF50+
• Ultra Violette Lean Screen SPF50+
• Ultra Violette Velvet Screen SPF50 (product export only – not available in Australia)
• People4Ocean SPF 50+ Mineral Bioactive Shield Lightly Tinted Cream
• McoBeauty SPF50+ Mineral Mattifying Sunscreen
• Naked Sundays Collagen Glow Mineral Sunscreen
• Outside Beauty & Skincare SPF 50+ Mineral Primer
• Salus SPF50+ Daily Facial Sunscreen Broad Spectrum