J. Cosmet. Sci., 63, 255–258 ( July/August 2012) 255 Sand resistance of sunscreens MICHAEL CASWELL, CARYL WOOD, and ALEXA MARTINEZ, Consumer Product Testing Company, Inc., 70 New Dutch Lane, Fairfi eld, NJ 07004. Accepted for publication November 30, 2011. A portion of this data was presented at the 2011 Sunscreen Symposium, Orlando, Florida, September 15-18, 2011. Synopsis Like water resistance in sunscreens, sand resistance in sunscreens is the ability of the sunscreen to retain its effectiveness while undergoing sand treatment. The infl uence of the type of sand on the sand resistance of sunscreens has not been described. The sand resistance of a control standard sunscreen, P2, and data on three grades of Quickrete® commercial grade sand, #1961, #1962, and #1152, are described. These sands represent a fi ne sand, a medium sand, and an all-purpose sand. Using the methodology described in the 2007 proposed amendment of the Final Monograph (1) with one exception, we obtained an SPF of 16.5 (1.6) for the control standard, compared to the expected SPF of 16.3 (3.4). After a fi ve-minute treatment of sand #1961, #1962, or #1151, the SPF of the control standard was 18.3 (1.6), 18.4 (2.0), and 17.5 (2.2), respectively. Thus, all three sands exhibited a similar sand-resistance response. Thus, there was no signifi cant difference in the average SPF with and without sand. The medium grade sand, Quickrete® commercial grade #1962, was preferred for sand- resistance testing because the fi ne sand was diffi cult to remove from the subject’s backs and the coarse sand was unpleasant to the subjects. INTRODUCTION Typical sunscreen formulations leave on the skin a fi lm that is frequently tacky. As sunscreens are frequently used on sandy beaches, the sand may be held to the skin, causing an unpleasant experience by the consumer. The consumer may brush off the sand with unknown consequences to the effi cacy of the sunscreen. Water-resistance SPF testing according to the Final Monograph (1) is a method to deter- mine the SPF of a sunscreen drug product after a defi ned period of water exposure. Simi- larly, sand-resistance SPF testing is a method to determine the SPF of a sunscreen drug product after a defi ned period of sand exposure. This clinical trial was designed to determine if the grade of the sand that is poured onto the sunscreen-treated skin and brushed off has a statistically signifi cant effect on the SPF of a control standard sunscreen. Address all correspondence to Michael Caswell at mcaswell@cptclabs.com.

JOURNAL OF COSMETIC SCIENCE 256 MATERIALS AND METHODS Multi-port 300-watt xenon arc solar simulators equipped with WG320 and UG11 fi lters were used as the source of full-spectrum UV radiation (Solar Light Company, Philadelphia, PA). These instruments provide a spectral output in both the UVB range (290 nm–320 nm) and the UVA range (320 nm–400 nm) that is similar to that of sunlight (2). The solar simulators provided an appropriate warm-up period of approximately 30 minutes after which their output was measured with a UV intensity meter (Model PMA2100, Solar Light Company). Measurement of output was also measured at the end of the day to ensure that there were no fl uctuations in radiation emission. To ensure that the solar simulators deliver the appropriate spectrum of UV radiation, their spectral output is mea- sured semi-annually with an accurately calibrated spectroradiometer. Three different grades of Quickrete® commercial sand was obtained from Quickrete®, Flanders, NJ. Grade #1961 is a fi ne sand with a US sieve number of 30–70 (0.2–0.6 mm), grade #1962 is a medium sand with a US sieve number of 20–50 (0.5–0.3 mm), and grade #1152 is a coarse sand that meets ASTM C33 specifi cations. The exact US sieve number is unknown. Each grade of sand was dried for approximately 24 hours in a 90°C oven and then allowed to cool to room temperature prior to use. A control standard sunscreen (lot #CLI740901) was obtained from Cosmetech Laboratories, Inc. (Fairfi eld, NJ). The actives were padimate O (7.0%) and oxybenzone (3.0%). The trial was conducted between February 4 and November 10, 2010, according to the World Medical Association Declaration of Helsinki. Potential subjects were recruited from the database at Consumer Product Testing Company, Inc., which currently contains information on more than 60,000 potential subjects. Potential subjects had the benefi ts and risks of the clinical trial described to them and they were allowed an opportunity to ask any questions. Once they signed the informed consent and became subjects, they were evaluated for qualifi cation into the trial. The inclusion criteria included Fitzpatrick skin phototypes I, II or III, the previous reliability of the subject, and an age of 18 to 65 years (inclusive). The exclusion criteria included ill health, medications that would interfere with the trial, recent overexposure to UV, a history of adverse reactions to cosmetics or OTC drugs, and pregnancy or nursing. All 20 subjects completed the trial without any adverse event. All procedures were conducted in ambient conditions (18°–26°C) while the subject was in the prone position. Each subject had fi ve 50-cm2 test sites outlined with a surgical marking pen on the subject’s back between the scapulae and the beltline, lateral to the midline. One site was for determining the unprotected MED, one site was for determin- ing the protected MED, and the other three sites were for determining the protected MED after treatment with one of the three grades of sand. The control standard sunscreen was applied and spread evenly over each of four test sites with a fi nger wearing a fi ngercot to provide a fi lm of approximately 2.0 mg/cm2. Approximately fi ve minutes after completion of the control standard application, approx- imately 30 ml of one grade of sand was poured from a height of approximately four inches over a time period of approximately 15 seconds. The sand remained on the sunscreen fi lm for fi ve minutes before being gently brushed off with a one-inch paintbrush. The brush- ing was conducted in a manner similar to that used when painting.