Question

Is stearic acid polyoxyethylene ether SG-9 harmful to the human body? Does it have an impact on the environment?

Answer
2026-06-06 官方文档 硬脂酸聚氧乙烯醚SG-9

Stearic acid polyoxyethylene ether SG-9 is a low-toxicity, non-hazardous substance, with irritation as the main effect on the human body, and it has certain hazards to aquatic organisms but is readily biodegradable, showing overall good safety.

Detailed Explanation

Stearic acid polyoxyethylene ether SG-9 (PEG-9 stearate) is a nonionic surfactant, not listed under GHS hazardous chemical classification, and is not considered a dangerous good. From an acute toxicity perspective, its oral LD50 in rats is greater than 2000 mg/kg, indicating low toxicity. The Ames test is negative, showing no mutagenicity, and under normal use conditions, it does not cause severe systemic poisoning hazards to the human body.

The main potential impact on human health centers on local irritation. According to risk phrases R36/37/38, this product is irritating to the eyes, respiratory system, and skin. Animal experimental data show: skin contact in rabbits for 4 hours results in mild irritation, and eye contact in rabbits results in moderate irritation. Therefore, during industrial operations or formulation use, accidental eye contact may cause significant discomfort and requires immediate flushing; it may also cause mild erythema or dryness in sensitive individuals. However, due to significant dilution in the final product (e.g., cosmetic formulations), this irritation is usually markedly reduced.

From an environmental perspective, the LC50 (96h for fish) of this product for aquatic organisms is 10–100 mg/L, indicating some hazard to aquatic organisms, and large direct discharges into water bodies could affect aquatic ecosystems. However, it is commendable that this product is readily biodegradable (biodegradation rate >60% under OECD 301B method), does not accumulate long-term in the natural environment, and the overall environmental risk is manageable. The key is to properly collect and treat industrial wastewater and spillage to avoid direct discharge untreated into soil, drains, sewers, and natural water bodies.

Technical Parameters

Assessment DimensionIndicatorData
Human HealthAcute Toxicity (Rat Oral LD50)>2000 mg/kg, low toxicity
Skin Irritation (Rabbit, 4h)Mild irritation
Eye Irritation (Rabbit)Moderate irritation
Mutagenicity (Ames Test)Negative, no mutagenicity
Environmental ImpactEcotoxicity LC50 (Fish, 96h)>10–100 mg/L, harmful to aquatic organisms
Biodegradability (OECD 301B)>60%, readily biodegradable
Heavy Metal Content≤10 mg/kg (Arsenic ≤2 mg/kg)
Hazard ClassificationGHS ClassificationNot classified, non-hazardous
Risk PhrasesR36/37/38Irritating to eyes, respiratory system, and skin

Application Recommendations

Based on the above safety and environmental characteristics, proper usage recommendations for stearic acid polyoxyethylene ether SG-9 are as follows:

  • Industrial Operation Protection: In direct contact processes such as feeding and packaging, wear chemical safety goggles, chemical-resistant gloves, and protective clothing; maintain good ventilation in the workplace to avoid inhalation of dust or mist. Thoroughly wash hands and exposed skin after operation.
  • Formulation Application Safety: When used as an emulsifier in cosmetics, textile auxiliaries, and pesticide formulations, after dilution and compounding, the irritation is significantly reduced, making it a safe and compliant industrial raw material. In cosmetic applications, conventional addition levels meet safety requirements.
  • Wastewater Treatment: Industrial wastewater containing this product should be treated in a wastewater treatment system to meet discharge standards before release; direct discharge is not allowed. Due to its ready biodegradability, conventional biological treatment processes can effectively remove it.
  • Spill Handling: Small spills: collect with inert absorbent and seal in a closed container for disposal; large spills: isolate the area, prevent entry into drains and water bodies, and dispose of waste according to local regulations.

Precautions

  • Although the LD50 indicates low toxicity, it is strictly prohibited for ingestion, and industrial grade products must not be used directly in food.
  • If eye contact occurs, immediately flush with plenty of running water for at least 15 minutes and seek medical attention, as it has moderate eye irritation.
  • Storage temperature is recommended to be ≤35°C, away from strong oxidizers and strong acids and other incompatible substances.
  • Combustion may produce harmful gases such as carbon monoxide; firefighters should wear self-contained breathing apparatus when extinguishing fires.
  • Although the product is readily biodegradable, the precautionary principle of "avoid release into the environment" should still be followed, and proper management of industrial waste (gas, liquid, solid) is necessary.

(All data above are sourced from Guoli Chemical Product Technical Data Sheet and Safety Data Sheet.)