Six frequently used UVA and UVB sunscreens were tested by the Institute of Pharmacology and Toxicology at the University of Zurch, Switzerland, for estrogenicity, and reported in “Environmental Health Perspectives,” Feb. 28, 2001.
Chemicals that are estrogenic can be considered endocrine disrupters, fooling the body into believing they were natural hormones, which can cause reproductive problems. The chemicals analyzed were
1. Benzophenone-3 (Bp-3)
2. Homosalate (HMS)
3. 4-methyl-benzylidene camphor (4-MBC)
4. Octyl-methoxycinnamate (OMC)
5. Octyl-dimethyl-PABA (OD-PABA)
7. Butyl-methoxydibenzoylmethane (B-MDM)
The first six of these chemicals, found in sunscreens of every type, were found to be estrogenic, whereas the seventh was inactive. The researchers concluded that there was enough evidence of estrogenicity for further studies to be warranted.
Abiding by the Precautionary Principle, it makes sense to choose products free of these chemicals until more research has been completed into possible long-term effects in humans and wildlife.
Chemical-free and natural sunscreens use titanium dioxide and zinc oxide. They are physical barrier-type sunscreens and generally less irritating. Zinc oxide and titanium dioxide protect against UVA and UVB rays.
Brands using these natural sunscreens include Aubrey Organics’ Ultra Natural Herbal Sunblock, Titania SPF 25 Full Spectrum Sunblock, and Green Tea Sunblock (ingredients in green tea have been shown to protect against skin cancer); and Logona Kosmetik’s Sun Milk line of mineral sun protection products. Read labels carefully.
Important Note: Until recently, sunscreens have protected only against UVB rays, not UVA rays. UVB rays cause sunburn, and if you screen them you might stay in the sun longer, overexposing yourself unprotected to UVA rays. UV rays are the most intense from 10 A.M. to 2 P.M. We need to wear sunblock effective against UVA and UVB rays, with an SPF of at least 15, year-round. As noted above, zinc oxide and titanium dioxide protect against UVA and UVB rays.