On the safe dosage of glycolic acid
The safe dosage of glycolic acid should be known first. Glycolic acid has unique chemical characteristics and is used in various fields. However, the control of dosage is related to effectiveness and safety.

In daily use, such as skin care products, the dosage should be cautious. The skin is the barrier of the human body, delicate and sensitive. If the dosage of glycolic acid is too large, it may cause skin discomfort, redness, itching in light cases, and molting and tingling in severe cases. Because the stratum corneum of the skin has its tolerance limit, excessive glycolic acid can break its structure and damage its protective ability. Therefore, in skin care products, the safe dosage often varies depending on the skin type. Generally speaking, for normal skin, the content of glycolic acid is between 2% and 5%, which can be regarded as a safe category. This amount can not only help the skin rejuvenate, exfoliate, promote metabolism, but also avoid excessive irritation. If it is sensitive skin, the dosage should be reduced, 1% to 3% is appropriate. When using it for the first time, it is especially necessary to try it on a small scale to see the reaction of the skin, and then determine whether it can be used.

In the industrial field, glycolic acid is used for cleaning, etching, etc. Although it is not in direct contact with the human body, its volatilization or wastewater discharge is also related to the environment and human health. For cleaning preparations, the concentration should also be set according to the material and degree of dirt of the cleaning object. If the metal surface is clean, the concentration of glycolic acid can be slightly higher, but it must also be controlled within the safe limit to prevent excessive corrosion of the metal. Usually, in such applications, the content of glycolic acid may reach 10% - 20%, but at the same time, corrosion inhibitors and other additives need to be added to ensure that the metal is not damaged and safe to use. When discharging, it is also necessary to follow environmental protection regulations and reduce the content of glycolic acid to below the specified standard to avoid pollution of the environment and pests.

In summary, the safe dosage of glycolic acid is not a general rule, and it is necessary to take into account many factors such as the application scene and the characteristics of the object. Use it cautiously, in order to promote its strengths and avoid its weaknesses, and achieve a balance between safety and efficacy.