Home >> ALL ISSUES >> 2018 Issues >> New requirements for use and storage of liquid nitrogen, dry ice

New requirements for use and storage of liquid nitrogen, dry ice

image_pdfCreate PDF
Valerie Neff Newitt

October 2018—Laboratory personnel safety is at the center of two new requirements and a revised requirement in the latest edition of the CAP accreditation program checklists, released in August.

The requirements address the risks and hazards associated with the use and storage of liquid nitrogen (LN2) and dry ice, and they apply to all laboratories in the Laboratory, Biorepository, and Reproductive Laboratory accreditation programs.

Another new safety-related requirement is about restricting access to the laboratory.

An employee of a non-CAP-accredited laboratory in Georgia was critically injured in 2017 when an LN2 leak occurred. LN2 converts to colorless, odorless gas and replaces environmental oxygen. The unsuspecting laboratory worker was burned and then fell unconscious. One of the first responders who arrived on the scene to rescue her died of asphyxi­ation. The employee survived.

Dr. Geaghan

Dr. Geaghan

CAP accreditation program leaders viewed that accident as an opportunity “for greater occupational safety and protection of lab workers,” says Sharon Geaghan, MD, emerita chief of pathology at Lucile Packard Children’s Hospital at Stanford, emerita co-director of Stanford Clinical Laboratories, and a member of the CAP Checklists Committee. “It is representative of the best work that the Checklists Committee can do—to act as a mechanism for the College to respond to current-day, real-life challenges.”

A group composed of members of the Checklists, Biorepository, and Reproductive Medicine committees came together to gather and share safe handling, storage, and usage practices from those areas of medicine most familiar with LN2 and dry ice use.

“We quickly realized there are many medical applications of liquid nitrogen in the health care environment that often are not appreciated,” Dr. Geaghan says. “There was a heightened recognition that this involves all types of labs, and safety training and measures are paramount.”

Philip A. Branton, MD, consulting pathologist in the Biorepositories and Biospecimen Research Branch at the National Institutes of Health and chair of the CAP Biorepository Committee, says while biorepositories were familiar with the hazards of LN2 even before the CAP’s Biorepository Accreditation Program got underway in 2012, “other labs may have lagged behind.” Now, however, “there is a new imperative to be familiar with the risks of liquid nitrogen and dry ice in day-to-day clinical medicine due to the rise of molecular medicine.” Tissue that once was fixed in formalin and examined under a microscope may now be snap-frozen and put into a repository at -80°F for later molecular testing for gene and marker identification, he notes. “More and more tissues are being frozen even in hospitals, not just research institutions, going down to the community hospital level. So safety pertaining to LN2 and dry ice must be addressed across all lab types.”

Dr. Branton

Revised requirement GEN.77500 “Liquid Nitrogen and Dry Ice” (which is in the biorepository checklist as GEN.85960) directs labs to have “adequate policies, procedures, and practices” for not only the use of LN2 but also now dry ice. Notes define what is required for safely handling LN2 and dry ice.

“The revised requirement has changed the notion of appropriate equipment being determined at the discretion of lab directors,” says Jacob Frank Mayer Jr., PhD, a professor of obstetrics and gynecology at Eastern Virginia Medical School, Norfolk, and former director of the Jones Institute for Reproductive Medicine embryology laboratory. Dr. Mayer, who is a member of the CAP Reproductive Medicine Committee and deputy regional commissioner for the Reproductive Laboratory Accreditation Program, says, “We wanted to take some of the leeway out of it and stipulate that specific protective equipment must be used.”

Laboratories are warned not to store LN2 or dry ice “in confined areas, walk-in refrigerators, environmental chambers, or rooms without ventilation.” The note says, “An LN2 or CO2 leak in such an area could cause an oxygen-deficient atmosphere.”

Dr. West

A couple of asphyxiation deaths due to nitrogen have occurred every year for the past 10 years, says William West, MD, staff pathologist at CHI/Creighton University Medical Center and chair of the Checklists Committee, citing OSHA data. Dr. Geaghan referenced a 2003 report from the U.S. Chemical Safety and Hazard Investigation Board, which she says revealed that in the prior decade there were 85 nitrogen asphyxiation incidents in a variety of settings, some of them medical laboratories and facilities.

Too often, Dr. West says, people don’t comprehend the rapidity with which asphyxiation from nitrogen occurs. “A person need only take a breath or two to become unconscious.”

CAP TODAY
X