Chemical Hazards for Health Care Workers and How to Reduce Them

Health care workers use hazardous chemicals to treat patients, clean and disinfect surfaces and instruments, and preserve tissue specimens. Those chemicals can expose workers, patients and others. The National Institute for Occupational Safety and Health (NIOSH) outlines the main risks and the safety steps that lower them.

Aerosolized medications

Medicines for respiratory diseases and infections are often given through a nebulizer or other aerosol generator, which can expose the staff giving them. To reduce exposure:

• wear protective gloves and gowns to avoid skin contact with hazardous drugs, and appropriate respiratory protection when drug aerosols are produced; and
• use delivery devices with one-way inspiratory and expiratory valves and an expiratory filter.

Anesthetic gases

Waste anesthetic gases are gases and vapors that leak into the room during anesthesia. Short-term exposure to halogenated anesthetics can cause headache, fatigue, irritability, drowsiness and impaired judgment and coordination; long-term exposure may harm reproduction and cause cancer. To reduce exposure:

• use anesthesia machines with scavenging systems (older machines may lack them);
• where practical, use closed-system or low-flow rather than high-flow anesthesia;
• start the gas flow only after the mask or airway is on the patient;
• fill vaporizers with a key-filler or other closed device to limit spills and evaporation; and
• train staff when they start and every year, and keep safe-handling procedures easy to find.

Antineoplastic drugs

These drugs treat cancer as well as arthritis, multiple sclerosis and other conditions; chemotherapy, cytotoxic and oncology drugs are all in this group. NIOSH classifies most as hazardous, and many are carcinogens with no safe level of exposure. At risk are pharmacists, veterinarians and veterinary technicians, nurses and nursing aides, and custodial workers — especially when preparing and giving the drugs, shipping and receiving them, laundering linens, handling patients' (including animal patients') bodily waste, or cleaning where the drugs were used. Exposed workers face higher risks of leukemia and other cancers, reproductive harm and chromosomal damage. To reduce exposure:

• avoid skin contact with the liquid drugs, and wear chemotherapy gloves and a nonabsorbent, closed-front gown with tight cuffs when preparing or giving them;
• prime IV tubing with a liquid that contains no hazardous drug;
• use engineering controls such as closed-system drug-transfer devices and needleless systems, and prepare the drugs in a biological safety cabinet; and
• train staff at hire and every year, and offer medical surveillance to exposed employees.

Chemical sterilants

Sterilants protect patients from germs on surgical instruments and supplies but can harm workers. Common ones are ethylene oxide (EtO), hydrogen peroxide gas plasma, vaporized hydrogen peroxide, and peracetic acid in immersion or vapor form.

• Ethylene oxide: short-term exposure can cause respiratory irritation, headache, nausea and shortness of breath; long-term exposure can cause cancer, reproductive effects, genetic mutations, nerve damage and sensitization.
• Hydrogen peroxide gas plasma and peracetic acid: short-term exposure may irritate the upper airways, and liquid solutions can irritate the skin.

Employers should train staff before they work with sterilants and provide standard operating procedures. Hospitals must sterilize and aerate EtO loads in a single chamber: the Environmental Protection Agency banned separate units in March 2010 to eliminate exposure during transfer.

High-level disinfectants

These chemically disinfect reusable medical and dental devices to prevent infections in patients. FDA-cleared products contain ingredients such as glutaraldehyde, ortho-phthalaldehyde, peracetic acid, hydrogen peroxide, hypochlorous acid and hypochlorite. Short-term exposure can cause dermatitis, irritation of the skin, mucous membranes and airways, and worsening of asthma; long-term exposure may cause asthma or reproductive effects, and hydrogen peroxide has been shown to cause mutations in animals. To reduce exposure, train staff in best practices before they work with them, keep spill kits on hand, and wear protective gloves and a water-resistant gown.

Nitrous oxide

Dental staff can be exposed to too much nitrous oxide when engineering controls (such as a scavenging nasal mask or local exhaust ventilation near the patient's mouth), administrative controls and work practices are missing or misused. Short-term exposure may cause lightheadedness, eye and airway irritation, coughing, shortness of breath and reduced mental performance and dexterity; long-term exposure may raise the risk of neurologic, kidney and liver disease, miscarriage and fertility problems. To reduce exposure:

• test connections for leaks with a soap solution daily before first use and whenever a cylinder is changed;
• start the gas only after the nasal mask is on the patient, and turn it off before the oxygen; and
• keep safe-handling procedures accessible and train staff at hire and every year.

Sources

• National Institute for Occupational Safety and Health, CDC, "Chemical Hazards Risk Factors": https://www.cdc.gov/niosh/healthcare/risk-factors/chemical-hazards.html
• The source spells ortho-phthalaldehyde "Ortho-Phthaldehyde."