Hydroxypropyl methyl cellulose(HPMC) is a white or off white powder. Mainly used as a dispersant in the production of polyvinyl chloride, and also as a thickener, stabilizer, emulsifier, film-forming agent, etc. in the production of other petrochemical, coating, building materials, paint remover, papermaking, cosmetics and other products.

Hydroxypropyl methylcellulose is not harmful to the human body, but long-term excessive intake may have some adverse effects on the human body. Regarding its security, the following is a detailed answer:

Matters needing attention:

Long term and large intake: Although hydroxypropyl methylcellulose itself is relatively safe, long-term and large intake may lead to an imbalance of gut microbiota, causing problems such as diarrhea.

Usage and method: The safety of hydroxypropyl methyl cellulose is closely related to its usage and method. During use, the manufacturer's recommended dosage and instructions should be strictly followed to avoid unnecessary risks.

Protection in industrial environments: In the production or use environment of hydroxypropyl methylcellulose, workers should pay attention to wearing appropriate protective equipment, 

such as masks and gloves, to prevent dust inhalation or skin contact.

In summary, hydroxypropyl methylcellulose is harmless to the human body under normal circumstances, but attention should still be paid to its potential risks and correct usage methods.