According to statistics, each woman uses an average of 12 different cosmetics every day, which inadvertently armed themselves with 175 different chemical ingredients; at the same time, there are a large number of the same chemical ingredients in toiletries. The following types of chemical ingredients in cosmetics and toiletries are the most common and most harmful: a. Moisturizing creams and lotions. Contains hydroxybenzoate protective ingredients, which can easily lead to breast cancer and dermatitis, etc. Second, shampoo shampoo. Contains sodium dodecyl sulfate and sodium dodecyl sulfate and other foaming ingredients, will irritate the skin, leading to skin allergies, dermatitis, etc. Third, hair care products, hand soap. Contains our common formaldehyde, it will cause the skin to produce a burning sensation, while may lead to asthma, headaches, etc. Fourth, bubble bath. Contains sulfur, sodium and other irritants, long-term use may cause skin redness, swelling, allergies, headaches and other phenomena, and even lead to cancer. How to use cosmetics scientifically? A. Avoid using multiple cosmetics at the same time. The only basic skin care steps a person has to do every day are: moisturizing, isolation, and sun protection. If you have to wear makeup due to professional needs, try to minimize the types of cosmetics. Second, many women often use fragrance intensity as a measure of cosmetic ideal or not. In fact, fragrance is only an additive used to meet people’s demand for cosmetic scent. The more complex the fragrance composition, the heavier the stimulation, the more likely it is to cause skin allergies and photosensitivity reactions. Some studies have shown that some cosmetic preservatives, fragrances and colors also contain toxic substances that can cause cell mutations and cancer. Third, do not “hunt” to choose new bath and make-up products, some traditional, old products are more environmentally friendly, but also healthier. In the purchase of cosmetics, as far as possible, choose a reputable, large professional company to produce brand-name products, do not want to buy and use cheap cosmetics without labeling the name, address, production license or production date, shelf life. Cosmetics lead to “cosmetic allergy syndrome” and its performance are the following situations: First, the role of stimulation. Cosmetics synthetic chemicals such as pigments and fragrances in contact with the skin, can directly stimulate the skin to cause pruritus, neurodermatitis and other diseases, some young people now like black hair dyed yellow, not knowing that the peroxide in the potion and ammonia, ammonium peroxymonosulfate can stimulate the scalp to increase dandruff, scalp burning, hair becomes brittle and easy to break. Nail polish remover – acetone, can make the nails brittle. Second, allergic reactions. For some people with allergic qualities, in the use of certain cosmetics, such as lipstick in the permanent dyes dibromo and tetrabromo fluorescein, and cosmetics containing lanolin various fragrances and preservatives, can cause allergic contact dermatitis. High concentrations of perfume, deodorant, hair milk in some allergic body can cause a variety of allergic reactions, causing spasmodic cough, allergic rhinitis, conjunctivitis, hives, etc.. Third, photosensitivity reactions. Lipstick and other cosmetics can damage the deoxyribonucleic acid of cells after absorbing the energy of visible light, which can cause mutation of cells and induce lip cancer. Sandalwood oil, lemon oil, etc. are photosensitive substances, and the skin coated with these cosmetics will suffer cell damage and inflammatory reactions under sunlight exposure. Fourth, pigmentation. Some cosmetics, such as pure jasmine oil, sandalwood oil, geranium oil, etc. can cause some women to appear “pigmented cosmetic dermatitis”. The manifestation is a diffuse, or patchy light brown pigmentation on the cheek or forehead, sometimes with mild erythema or papules, with itching sensation. For this reason, readers who use cosmetics are advised to: first read the instructions carefully and use them according to the instructions, but also apply a small amount of cosmetics on the inside of the forearm and wait 24 hours to observe any adverse reactions, such as reactions are prohibited, should not use imported cosmetics without Chinese labels.