The first phase of the study is an Induction Phase; a known amount of each product (test and control) is applied, under a semi-occlusive patch. Patches will remain on the skin for 48 (±2) (weekdays) or 72 (±2) (including inclusive weekends) hours during this phase. Induction phase lasts for 3 weeks. After the Induction Phase participants will enter a Rest Phase of 2 weeks duration, during which no patches are applied. After the Rest Phase, participants will return to the clinical site for the Challenge Phase. In this phase a challenge patch containing the test and control products is applied to virgin skin for 48 (±2) hours then assessed 30 minutes (maximum 1 hour) following removal, 24 (± 2) and 48 (±2) hours later.