: Surfactants are a relatively rare cause of allergic contact dermatitis (ACD) and testing patients to personal care products containing these ingredients has historically been difficult given their irritant properties. Using the semiopen technique, we were able to identify ACD to a hypoallergenic liquid cleanser in 2 patients who presented to our patch test clinic only months apart. Additional patch testing to individual ingredients led to subsequent identification of 3 novel surfactant allergens (sodium lauroyl sarcosinate, isostearamidopropyl morpholine lactate, and disodium lauroamphodiacetate). Only one of these allergens, sodium lauroyl sarcosinate, has previously been reported as a cause of ACD.