http://www.fda.gov/Cosmetics/GuidanceRegulation/GuidanceDocuments/ucm090816.htm
“Based on the available information included in this report, the
CIR Expert Panel concludes that Glycolic and Lactic Acid, their common
salts and their simple esters, are safe for use in cosmetic products at
concentrations ≤10%, at final formulation pH ≥3.5, when formulated to
avoid increasing sun sensitivity or when directions for use include the
daily use of sun protection. These ingredients are safe for use in salon
products at concentrations ≤30%, at final formulation pH ≥3.0, in
products designed for brief, discontinuous use followed by thorough
rinsing from the skin, when applied by trained professionals, and when
application is accompanied by directions for the daily use of sun
protection.”
Sunburn Alert: This product contains an alpha hydroxy acid (AHA)
that may increase your skin’s sensitivity to the sun and particularly
the possibility of sunburn. Use a sunscreen, wear protective clothing,
and limit sun exposure while using this product and for a week
afterwards.
Salicylic Acid is of course covered in an FDA OTC Monograph. As I stated a Regulatory Person (well respected) advised a client of mine that she could not combine Salicylic Acid with Glycolic Acid.