Patch Test of Benzalkonium Chloride Disinfectant Spray

Inclusion Criteria: 1. Consent: Demonstrates understanding of the study and willingness to participate as evidenced by voluntary written informed consent and has received a signed and dated copy of the informed consent form. 2. Compliance: Understands and is willing, able and likely to comply with all study procedures and restrictions, and will agree to not participate in any other study during the entire length of the study. 3. General Health: Good general health with (in the opinion of the investigator) no clinically significant and relevant abnormalities of medical history and vital signs at the screening. 4. Contraception: Females of childbearing potential who are, in the opinion of the investigator, practising a reliable method of contraception. Exclusion Criteria: 1. Pregnancy: Woman who is pregnant or who has a positive urine pregnancy test (just for females of childbearing potential) at the baseline. 2. Breast-feeding: Woman who is breast-feeding. 3. Allergy/Intolerance: Known or suspected intolerance or hypersensitivity to the study materials or have self-reported "sensitive skin" or a history of dermal hypersensitivity. 4. Clinical Study/Experimental Medication: Participation in another clinical study or receipt of an investigational drug within 30 days of the screening visit, including those who have taken part in any predictive irritation study or sensitisation test. 5. Substance abuse: Recent history (within the last 1 year) of alcohol or other substance abuse. 6. Personnel: An employee of the sponsor or the study site or members of their immediate family. 7. Participant who is currently taking any of the following medications: * Any topical or systemic treatments that may mask or interfere with the test results, specifically topical and/or systemic corticosteroids, non steroidal anti-inflammatory drugs (e.g. ibuprofen, aspirin), antihistamines and immunosuppressive in the past 30 days. And those taking medications which in the opinion of the clinical investigator may affect test results. * Topical anti-inflammation treatment in the aimed application area in the past 2 months. 8. Participant who has a history of any acute or chronic disease that might interfere with or increase the risk on study participation. (e.g., atopic dermatitis/eczema, systemic lupus erythematosus, rheumatoid arthritis, other autoimmune diseases, asthma and other chronic respiratory disease). 10\. Participant who has damaged skin in close proximity to test sites (e.g., sunburn, uneven skin pigmentation, tattoos, scars, birthmarks or other disfigurations). And those who are suffering from any active skin disorders, conditions, or any visible skin disease which might be confused with a skin reaction from the test materials. 11\. Participant who requires use of any emollient on the upper back throughout the study or who use of any emollient or other skin care product on the upper back in the past 3 days.