The combination of green tea waste extract and rice washing water as peel-off gel mask was stable up to 28 days storage and had IC50 value 20.4 ppm. This potential can provide an optimum effect as cosmetics. However, to catch up Badan Pengawas Obat Makanan (BPOM) RI regulations and ISO 10993, dermal sensitization test also need to be done. The aim of this study to determine dermal sensitization reaction on appropriation of peel-off gel mask combination of green tea waste extract (Camellia sinensis L.) and rice washing water (Oryza sativa L.) with animal testing. The research was designed based on experimental laboratories method and simple randomize sample. The intervention was given by posttest-only control group design. Test of dermal sensitization reaction determined by Guinea Pig Maximization Test (GPMT) method. The results showed that the reaction of erythema and edema appeared based on Magnusson and Kligman scale after administration of sodium dodecyl sulfate (SDS) and peel-off gel mask as sample in the topical test on the 11th and 24th days of the challenge test. This is happened because one week incubation time to increase hypersensitivity reaction which also called delayed hypersensitivity reaction. In addition, the weight of test animals in each group was decreased due to environmental factors and the ability of animals to adapt.