Skin care products containing low concentrations of formaldehyde detected by the chromotropic acid method can not be safely used in formaldehyde-allergic patients.
Preservatives are widely used to prevent microbial growth both for skin care products and in the industry. Many of them have allergic potential. Allergic contact dermatitis caused by preservatives can often be chronic, probably because it is difficult to suspect contact allergy to these chemicals based on the patient's history only. Formaldehyde is a common cause of contact allergy and has been in