Safety of Surfactants
Surfactants and their metabolites induce biological changes in the organism, namely potential toxic and side effects on the body, including acute toxicity, subacute toxicity, chronic toxicity, impacts on fertility and reproduction, embryonic toxicity, teratogenicity, mutagenicity, carcinogenicity, sensitization, hemolysis and so on. Surfactants come into contact with different parts of the human body in various ways, and different requirements are set for the above-mentioned toxic and side effects accordingly.
Surfactants are increasingly widely applied in systems that come into contact with the human body, such as pharmaceuticals, food, cosmetics and personal hygiene products. With the improvement of people’s living standards, more and more attention has been paid to the toxic and side effects of surfactants in various human-contact formulations. For different application purposes, the key concerns regarding surfactants mainly focus on mucosal irritation, skin sensitization, toxicity, genetic toxicity, carcinogenicity, teratogenicity, hemolysis, digestibility and absorbability, as well as biodegradability. For instance, in the field of cosmetics, the traditional principle of ingredient selection prioritized cosmetic effects. When choosing surfactants, consideration was only given to achieving the optimal primary functions such as cleaning, foaming, emulsification and dispersion; secondary or auxiliary functions were only regarded as secondary concerns, while little or no consideration was given to the impact of surfactants on the natural condition of skin and hair. Nowadays, the selection principle of surfactants has gradually shifted to first ensuring the protection of the normal and healthy state of skin and hair and minimizing toxic and side effects on the human body, before taking into account how to exert the optimal primary and auxiliary functions of surfactants. This development trend poses a challenge to surfactant raw material suppliers, formulators and manufacturers, that is, how to re-recognize and evaluate the safety and mildness of surfactants, so as to provide consumers with products that are the safest, mildest and most effective. Therefore, it is extremely necessary to re-evaluate the safety and mildness of both existing and new types of surfactants.
Cationic surfactants are commonly used as disinfectants and bactericides, with a strong killing effect on various bacteria, molds and fungi, but they also produce toxic and side effects simultaneously. They can degrade the functions of the central nervous system and respiratory system, and cause gastric congestion. Anionic surfactants have relatively low toxicity and will not cause acute toxic harm to the human body within the conventional application concentration range, but oral intake may cause gastrointestinal discomfort and diarrhea. Nonionic surfactants are low-toxic or non-toxic and are non-poisonous via oral administration. Among them, PEG surfactants have the lowest toxicity, followed by sugar esters, AEO, Span and Tween series, while alkylphenol ethoxylates have relatively higher toxicity.
For aquatic animals, the overall toxicity of nonionic surfactants is higher than that of anionic surfactants.
Subacute and chronic toxicity tests generally take a long time. Due to differences in experimental animals and other experimental conditions, it is difficult to compare various data. However, it is generally acknowledged that the subacute and chronic toxicity test results of nonionic surfactants fall into the non-toxic category. Long-term intake will not cause pathological reactions. Only some varieties may increase the human body’s absorption of fats, vitamins or other substances, or induce reversible functional changes in certain organs when taken orally at high doses. Therefore, nonionic surfactants can be used as substances with high safety.
In food industry, nonionic surfactants are commonly used as emulsifiers. At times, their functions such as foaming, defoaming, wetting, dispersing, anti-crystallization, anti-aging, retrogradation prevention, water retention, sterilization and antioxidant properties are also required. Surfactants used as food emulsifiers are subject to strict restrictions. Only a few varieties are generally approved for use, and some are further limited by the Acceptable Daily Intake (ADI, mg/kg) index, which refers to the maximum dose of a certain additive that the human body can continuously ingest per unit body weight without causing adverse health effects.
Nonionic surfactants are commonly used as solubilizers, emulsifiers or suspending agents in pharmaceutical injections and nutrient injections. For scenarios involving a large single injection volume, especially intravenous injection, the hemolytic property of surfactants must be taken seriously. Anionic surfactants exhibit the strongest hemolytic effect and are generally not used in injections; cationic surfactants rank second in hemolytic activity, while nonionic surfactants have the lowest hemolytic potential. Among nonionic surfactants, hydrogenated castor oil acid PEG esters show relatively low hemolytic effects and are most suitable for intravenous injection. However, increasing the degree of PEG polymerization will result in higher hemolytic activity than Tween-type surfactants. The hemolytic order of nonionic surfactants is: Tween ＜ PEG fatty acid ester ＜ PRG alkylphenol ＜ AEO. Within the Tween series, the hemolytic order is: Tween 80.
Post time: May-12-2026