Toxic List – M


Mercury is a silvery white metallic element that is a liquid at room temperature. Mercury is used in thermometers, vapor lamps, batteries, barometers, and in the manufacture of chemical pesticides. Mercury is extremely toxic and can cause serious health effects, such as tremors, sleep disturbance, and impaired cognitive skills. Mercury should be handled with extreme care and if there is a spill, specific cleaning procedures should be used to prevent toxic exposure.


Metaldehyde is an organic compound that is commonly used as a pesticide against snails, slugs, and other kinds of gastropods. Metaldehyde is mildly toxic and an irritant to breathing.

Methylene chloride

Methylene chloride, also known as dichloromethane, is a volatile, colorless liquid that is used in a variety of industrial processes and work activities, including paint stripping, paint remover manufacturing, metal cleaning and degreasing, and pharmaceutical manufacturing. Methylene chloride is a potential occupational carcinogen. Exposure to methylene chloride can lead to cancer, adverse effects on the heart, and skin or eye irritation.


Researchers are yet to reach a consensus about the safety of microwave ovens. All microwave ovens emit some microwaves, the exposure to which can lead to symptoms like loss of sleep, decreased heart rate, greater frequency of viral infections, and headaches. Microwaves have also been linked to birth defects and cancer. The FDA allows microwave emissions of up to one milliwatt/sq cm for a new microwave oven and up to five milliwatts/sq cm for a used oven. Having conducted studies with laboratory animals, Bell Telephone Laboratories recommends limiting microwave exposure to one milliwatt per day. In Russia, exposure above one milliwatt for more than one minute is prohibited.


Morpholine is an organic chemical compound that is used as a fruit coating and as an ingredient in fungicides. Morpholine irritates the eyes, skin, and mucous membranes, and it is has been linked to liver and kidney damage.

Mineral oil

Mineral oil is a liquid byproduct of the distillation of petroleum. It is widely used as a general purpose lubricant and coolant because of its low cost. Symptoms of mineral oil exposure include irritation to the respiratory tract, skin irritation, vomiting, and diarrhea.

Methylisothiazolinone (MIT)

MIT is a powerful biocide and preservative that is commonly found in shampoo and other body care products. It is often the active ingredient in antimicrobial soaps. MIT is allergenic and cytotoxic, and recent studies have shown that it causes nerve damage.


Methylchloroisothiazolinone is a preservative with antibacterial and antifungal properties. Many cosmetic and personal care products contain this chemical, and it is also used in industrial processes, like glue production. In pure form or in high concentrations, methylchloroisothiazolinone can irritate the skin and cause chemical burns.