All SPF lip balms are not created equal. In fact some can actually harm your gut and cells in your colon when ingested, found researchers in a study published in journal Chemical Research in Toxicology.
The culprit is sunscreen (or zinc oxide) nanoparticles defined as itty-bitty particles, not detectable to the eye, that are described by the US wellness publisher Rodale as "one/one hundred thousandth of the width of a human hair."
Philip Moos, assistant pharmacology and toxicology professor at the University of Utah in the US, led the study and found that when children and adults alike lick their lips and have a sunblock or SPF lip balm on their lips the sunscreen particles are "twice as toxic to the cells as larger particles."
"There have been some concerns about different nanomaterials, and zinc happens to be one that can be quite toxic if it comes into contact with cells," explained Moos to Rodale on June 29.
The bad news is nanoparticles aren't just found in some sunscreens, they are everywhere from cosmetics to iPhones and socks and even water filters.
As for the world of sunscreen, it can be confusing but you can avoid products with sunscreen nanoparticles. The best resource is the Environmental Working Group's (EWG) 2010 Sunscreen Guide, as they have tested products specifically for this.
Here are four SPF lip balms that will protect your pucker and gut:
UV Natural Lip Screen SPF 30+ ($9.50-12.50/€7.77-10.23)
UV Natural Sport Lip Screen 30+ ($10-12.50/€8.18-10.23)
Badger SPF 15 Sunscreen Lip Balm Unscented ($3.15/€2.57)
Purple Prairie Botanicals SunStuff Lip Balm, SPF 30 ($3.49/€2.85)
To find the top beach and sport suncreens, go to: http://www.ewg.org/2010sunscreen/best-beach-sport-sunscreens and the top SPF moisturizers: http://www.ewg.org/2010sunscreen/best-beach-sport-sunscreens/moisturizers-with-spf
Also in Australia, the laws are strict about sunblock labeling and you won't find anything over SPF 30+. The Cancer Council of Australia estimates over 1700 Australians die annually because of sun cancer. It is important to protect your skin and the Council has also endorsed a number of products:
Full study, "ZnO Particulate Matter Requires Cell Contact for Toxicity in Human Colon Cancer Cells": http://pubs.acs.org/doi/abs/10.1021/tx900203v