DMF is poisonous. Its Chinese name is dimethyl fumarate. It was invented and patented by Americans in 1940. It is used to preserve fruits and vegetables. It is usually packaged in small closed bags, like Desiccant is also used for anti-mold treatment. However, once the modified substance accelerates recovery from the packaging bag, it may penetrate into the product, causing redness, swelling, rashes, and in severe cases, skin ulcers and burns.