Laboratory testing of sunscreens on the US market finds lower in vitro SPF values than on labels and even less UVA protection

Abstract

Background: New research has attributed increased significance to the causal link between ultraviolet A (UVA) radiation and immunosuppression and carcinogenesis.In the United States, sunscreens are labeled with only their sun protection factor (SPF) and an imprecise term "broad-spectrum protection." Sunscreen marketing and efficacy evaluations continue to be based primarily on skin redness (sunburn) or erythema. We sought to evaluate the ultraviolet (UV) protection offered by common sunscreen products on the US market using laboratory-measured UV-absorption testing and comparing with computer-modeled protection and the labeled SPF values. This approach enables an investigation of the relationship between the labeled SPF and measured UVA protection, a factor that is ignored in current regulations.Methods: Fifty-one sunscreen products for sale in the United States with SPF values from 15 to 110 and labeled as providing broad-spectrum protection were tested using a commercial laboratory. All products were evaluated using the ISO 24443:2012 method for sunscreen effectiveness. The final absorbance spectra were used for analysis of in vitro UV protection. Results:In vitro SPF values from laboratory-measured UV absorption and computer modeling were on average just 59 and 42 percent of the labeled SPF. The majority of products provided significantly lower UVA protection with the average unweighted UVA protection factor just 24 percent of the labeled SPF. Conclusion:Regulations and marketplace forces promote sunscreens that reduce sunburn instead of products that provide better, more broad-spectrum UV protection. The production and use of products with broad spectrum UV protection should be incentivized, removing the emphasis on sunburn protection and ending testing on people.

Withania somnifera-derived carbon dots protect human epidermal cells against UVB-induced cell death and support growth factor-mediated wound healing

“…However, according to the Environmental Protection Group (EWG), only one of four products exhibit efficient UVA and UVB protection. 3 Additionally, a number of these sunscreens contain harmful chemicals that can injure individuals and the environment following an extended period of exposure.…”

“…However, according to the Environmental Protection Group (EWG), only one of four products exhibits efficient UVA and UVB protection. 3 Additionally, a number of these sunscreens contain harmful chemicals that can injure individuals and the environment following an extended period of exposure. The United States Food and Drug Administration (US-FDA) has designated titanium dioxide (TiO 2 ) and zinc oxide (ZnO) as GRASE ingredients up to a maximum level of 25 percent in certain over-the-counter sunscreen products.…”

Determining the ability to differentiate results between independent sun protection factor tests using the ISO24444 method

“…Consumer preferences driving sunscreen use are influenced by many factors, including marketing campaigns from sunscreen manufacturers, commentary from non-physician groups (such as consumer associations) who provide recommendations to the general public, and by the advice from healthcare professionals ( 9 , 14 ). Physicians typically prescribe sunscreens with high SPF values because it is expected that, for a variety of reasons such as a (wrongly assumed) expectation that a high SPF may be correlated with high UVA protection, that the use of sunscreen may lead to increased intentional sun exposure by consumers, or that sunscreen’s performance in real conditions is compromised, the real sun protection afforded from sunscreen products is less than the labeled SPF ( 6 , 10 , 14 – 18 ). Although in fact, the only information related to UVB protection available to physicians when recommending and to consumers when purchasing a sunscreen is the single SPF number shown on the product.…”

Characteristics of choice and satisfaction regarding the use of ultraviolet blockers in the golf population in Republic of Korea: A quantitative study

“…It is important to consider the selection of SPF‐specific sunscreen suitable for your skin 10 . Laboratory testing of sunscreens on the US market finds lower in vitro SPF values than on labels and even less UVA protection 11 . Many golf populations rely heavily on information to use various types of sun cream, sun spray, sun stick, and sun cushion.…”