Do FDA regulations make US sunscreens less effective than international products?
Unlike the EU, FDA regulations do not dictate standards or minimum requirements for UVA protection in sunscreen. Also unlike the EU, labeling relevant to UVA protection is not required (though allowed).
The answer on the sister-site (Outdoor.SE) as well as the other three quoted sites make the following claims: (Let me know if I missed anything.)
- US sunscreens "lack options for ingredients" (i.e. use fewer ingredients). True
- US sunscreens "are held to looser standards as far as how much UVA is blocked." True
- SPF in the US refers only to UVB and not to UVA. True
- UVA causes cancer. True
- US sunscreens are greasier. Undetermined
- US sunscreens are shorter lasting. False
The claims have been appended as true, false, or undetermined. See below for the detailed explanation for each claim.
US sunscreens "lack options for ingredients" (i.e. use fewer ingredients).
The FDA allows 16 "acceptable active ingredients in products that are labeled as sunscreen." From the FDA, the 16 ingredients are Aminobenzoic acid, Avobenzone, Cinoxate, Dioxybenzone, Homosalate, Meradimate, Octocrylene, Octinoxate, Octisalate, Oxybenzone, Padimate O, Ensulizole, Sulisobenzone, Titanium dioxide, Trolamine salicylate, and Zinc oxide.
Of the 16 ingredients, two are recognized as GRASE (generally recognized as safe and effective), two are not recognized as GRASE, and 12 are insufficiently studied to make a GRASE determination (source).
The EU allows 29 ingredients, which are listed here.
Chemical & Engineering News (C&EN) (published by the American Chemical Society) published an article describing this difference. (The article was published in 2015, so some numbers are inaccurate. The numbers I included above are the most up-to-date I could find.)
U.S. consumers don’t have access to eight advanced European sun-filtering molecules because the Food & Drug Administration is not convinced they are safe for users. Chemical and cosmetics industry executives counter that people are being denied potentially lifesaving protection. Despite legal efforts to break the stalemate, the wrangling could go on for many more years.
FDA’s current list contains 16 approved sunscreens, just eight of which are regularly used and only two of which offer good UV-A protection.
Other sunscreens on the FDA list are no longer used because they have an unpleasant feel, irritate skin, or are no longer made. One unused sunscreen, dioxybenzone, turns skin blue on UV exposure.
In a bit of irony, European regulators, who have a reputation for being more cautious about human exposure to chemicals than their U.S. colleagues, allow many more sunscreens. The European Union maintains a list of 27 sunscreen molecules, which, like the FDA-approved sunscreens, are subject to safety testing and maximum dosage restrictions.
The article goes on to state that the status of sunscreens in the EU vs. the US accounts for this difference. Sunscreens are regulated as cosmetics in the EU and as drugs in the US. As drugs, more restrictions apply. From the FDA:
In Europe and in some other countries, sunscreens are regulated as cosmetics, not as drugs, and are subject to different marketing requirements. Any sunscreen sold in the United States is regulated as a drug because it makes a drug claim - to help prevent sunburn or to decrease the risks of skin cancer and early skin aging caused by the sun.
This claim is true.
US sunscreens "are held to looser standards as far as how much UVA is blocked."
The FDA does not regulate the UVA effectiveness of US sunscreens. The most recent guidelines for sunscreens in the US are available here (emphasis added):
However, as discussed elsewhere in this final rule we are not requiring a UVA effectiveness rating on the PDP (see section III.B.)... As discussed in section III.B. of this document, we are not requiring a UVA effectiveness rating on the PDP.
The PDP is the product development protocol. From the FDA:
In the product development protocol (PDP) method for gaining marketing approval, the clinical evaluation of a device and the development of necessary information for marketing approval are merged into one regulatory mechanism. ... The PDP is essentially a contract that describes the agreed upon details of design and development activities, the outputs of these activites, and acceptance criteria for these outputs. It establishes reporting milestones that convey important information to the FDA as it is generated, where they can be reviewed and responded to in a timely manner.
This does not mean that manufacturers cannot test UVA effectiveness. In fact, the opposite is true and they are allowed to do so. From the FDA:
As of June 2011, sunscreens that pass the broad spectrum test can [not must] demonstrate that they also provide UVA protection. Therefore, under the label requirements, for sunscreens labeled "Broad Spectrum SPF [value]", they will indicate protection from both UVA and UVB radiation.
The EU does regulate the UVA effectiveness of EU sunscreens. From the EU (emphasis added):
Sunscreen products should be sufficiently effective against UVB and UVA radiation to ensure a high protection of public health. To this end, a sunscreen product should provide a minimum UVB and UVA protection.
Sunscreen products should protect against both UVB and UVA radiation.
The minimum degree of protection provided by sunscreen products should be as follows:
(b) a UVA protection of UVA protection factor of 1/3 of the sun protection factor, as obtained in application of the persistent pigment darkening method as modified by the French health agency Agence française de sécurité sanitaire des produits de santé – Afssaps or an equivalent degree of protection obtained with any in vitro method;
This claim is true in that US sunscreens are not required to test UVA effectiveness where EU sunscreens are required to do so and offer a "minimum degree of protection."
SPF in the US refers only to UVB and not to UVA.
From the FDA (emphasis added):
Because SPF values are determined from a test that measures protection against sunburn caused by UVB radiation, SPF values only indicate a sunscreen's UVB protection.
In fact, the FDA has discussed revising the SPF statement. From here:
In the 2007 sunscreen proposed rule, we proposed redefining the acronym “SPF” as the “sunburn protection factor.” We also proposed that the term “UVB SPF” would be required on the PDP of all OTC sunscreen products (proposed 21 CFR 352.50(a)). This term would be followed by the numerical value determined from SPF testing and one of the following descriptors: “low,” “medium,” “high,” or “highest.” For example, a sunscreen product could have contained the statement “UVB SPF 40 High” on the PDP.
The FDA ultimately decided against this.
This claim is true.
UVA causes cancer.
Both the FDA and the EU agree that UVA can cause cancer.
From the FDA:
It is well known that both UVA and UVB radiation contribute to photodamage and skin cancer (Refs. 6-7 and 10-12).
UVA and UVB radiation is the only known external risk factor for skin cancer and early skin aging.
From the EU (emphasis added):
As to the cancer risk, although UVB radiation is the main contributor, the risk generated through UVA radiation cannot be neglected. Furthermore, UVA radiation is cause of premature ageing of the skin. Research also suggests that excessive exposure to UVB radiation as well as UVA radiation impacts on the body's immune system.
There have been studies since the 2000s supporting the above conclusion (for example, see here).
This claim is true.
US sunscreens are greasier.
Greasier is a feeling that may, or may not, be consistently described. I am unsure how to evaluate this likely opinion-based statement. I did a search for scientific tests of greasiness and could only find science projects (such as [this](https://www.acs.org/content/dam/acsorg/education/resources/k-8/science-activities/chemicalphysicalchange/dissolving/release-the-grease.pdf one from the American Chemical Society). Thus, I do not think this claim can be scientifically tested to draw a definitive conclusion.
This claim is undetermined.
US sunscreens are shorter lasting.
The FDA recommends applying sunscreen every two hours. Additionally, manufacturers are required to include the direction "Reapply at least every 2 hours after towel drying, swimming, or sweating" in the most recent sunscreen labeling and effectiveness testing guidelines (source).
I couldn't find any instructions from the EU, except that "Products should provide guidance on the correct application of the product." (source). I would assume that there is no uniform standard for length of sunscreen effectiveness, that time between applications depends on manufacturer, and that some sunscreens are shorter lasting whereas others are longer lasting. In the absence of EU regulations, there could be sunscreens lasting less than 2 hours (the FDA standard).
This claim is likely false.
I would like to note that in 2017, Wang et al. studied 20 sunscreens. The results were:
Nineteen of 20 sunscreens (95%) met the US requirement of CW >370 nm. Eleven of 20 sunscreens (55%) met the EU desired ratio of UVA PF/SPF > 1:3.
The majority of tested sunscreens offered adequate UVA protection according to US Food and Drug Administration guidelines for broad-spectrum status, but almost half of the sunscreens tested did not pass standards set in the European Union.
UVA PF/SPF > 1:3 refers to the minimum degree of protection dictated by the EU that I quoted earlier ("a UVA protection of UVA protection factor of 1/3 of the sun protection factor"). For example, a UVA protection factor of 5 is required when the SPF is 15. The FDA has no such requirement. This study supports that EU standards are more stringent.