Methoxypolyethylene glycol (mPEG) is one of the most widely used water-soluble polymer materials in biochemistry, pharmaceutical formulation, cosmetic industry and organic synthesis. It possesses excellent biocompatibility, low immunogenicity and high hydrophilicity, commonly applied for PEGylation modification of protein drugs, peptides and small-molecule pharmaceuticals to prolong half-life, reduce immunogenicity and improve solubility and stability. In cosmetic and personal care products, it acts as a humectant, thickener, emulsifier and solubilizer, enhancing product texture and moisturizing performance without irritation to human skin. In organic synthesis and material chemistry, it serves as a green reaction solvent, phase transfer catalyst carrier and raw material for synthesizing PEG derivatives, block polymers and biodegradable materials. It is also extensively used in the preparation of drug sustained-release carriers, nanoparticle encapsulation, biological reagent excipients and industrial surfactant intermediates, showing irreplaceable value in biomedicine, daily chemicals and fine chemical industries.

This polymeric material is generally regarded as low-toxic and biologically safe under normal use conditions, but still requires standardized handling and basic protection. Dust or aerosol inhalation may cause mild irritation to the respiratory tract, leading to temporary throat dryness or slight cough in poorly ventilated environments. Direct skin contact rarely causes allergy; however, prolonged contact may bring slight dryness and tightness to sensitive skin groups. Eye contact with liquid or fine solid particles may induce mild conjunctival irritation, redness and foreign body sensation, which can be relieved by timely rinsing with plenty of clean water. Accidental ingestion of a small amount usually causes no obvious poisoning symptoms, while excessive intake may lead to mild gastrointestinal discomfort such as nausea and abdominal distension. During operation, wear ordinary dust mask, nitrile gloves and safety goggles, and work in a well-ventilated environment. Store tightly sealed in a cool dry place, away from strong oxidants and high-temperature heat sources. Waste materials and contaminated packaging should be disposed in accordance with general chemical waste regulations, and avoid arbitrary discharge to prevent unnecessary environmental accumulation and pollution.