Between 2% and 5% of the inhaled dose is oxidised in the liver, producing fluoride ions and difluoromethoxy-difluoroacetic acid.

[13] Like all potent inhalation anaesthetic agents it is a known trigger of malignant hyperthermia.

The obsolete (as an anaesthetic) agent methoxyflurane had a nephrotoxic effect and caused acute kidney injury, usually attributed to the liberation of fluoride ions from its metabolism.

[14] The U.S. National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) for exposure to waste anaesthetic gas of 2 ppm (15.1 mg/m3) over a 60-minute period.

Symptoms of occupational exposure to enflurane include eye irritation, central nervous system depression, analgesia, anesthesia, convulsions, and respiratory depression.