Confirmation of the risks of exposure to formaldehyde and formalin may encourage safety officers in pathology labs to use tissue processing methods that don’t use this chemical
Pathologists, histotechnologists, and other medical laboratory professionals who regularly work with formalin and other chemicals used in histology laboratories, know they are dangerous to the health of those who work with them daily. These other chemicals include xylene and toluene.
Last summer, the National Academy of Sciences (Academy) issued a statement declaring that the Academy concurs with the 2011 Report of Carcinogens (RoC) listing formaldehyde as a known cause of cancer in humans. It was in August when the Academy issued its statement on this issue.
Exposure to Formaldehyde Linked to Three Types of Cancer
The Report of Carcinogens concluded that there is positive correlation between exposure to formaldehyde and three types of cancer:
• Nasopharyngeal cancer; and,
Formalin is a form of formaldehyde, and for this reason the findings of the National Academy of Sciences will be of particular interest to pathologists and clinical laboratory managers who are responsible for health and safety in histology and cytology laboratories.
The decision by the Academy’s National Research Council (NRC) to confirm the 2011 National Toxicology Program (NTP) report that listed formaldehyde as a carcinogen was reported in a Chemical Regulation Reporter story.
Workers in Pathology Labs at Risk of Formaldehyde Exposure
Pathology laboratory technicians are among specific types of workers at greater risk of exposure to formaldehyde, according to the National Cancer Institute website. “Reducing exposure to cancer-causing agents is something we all want, and the Report on Carcinogens provides important information on substances that pose a cancer risk,” observed Linda Birnbaum, Ph.D., Director of both the National Institute of Environmental Health Sciences (NIEHS) and the NTP, in a news release.
In its 2011 Report of Carcinogens, the NTP upgraded its classification of formaldehyde to “known to be a human carcinogen.” As early as its 1981 report, NTP scientists had classified formaldehyde as “reasonably anticipated to be a human carcinogen.”
Chemical Industry Balks at Classifying Formaldehyde as a Known Carcinogen
The chemical industry balked at the upgrade, because of formaldehyde’s wide use. “For years, the chemical industry has been winning a political battle to keep formaldehyde from being declared a known carcinogen,” wrote journalist David Heath in a Center for Public Integrity (CPI) story.
Formaldehyde is considered a “building block” chemical, according to the CPI story. It is used in many consumer products. Among other things, these include, pressed wood, paper product coatings, permanent-press fabrics, glues and adhesives, and fiberglass, noted a fact sheet.
Formalin is a water-based solution of formaldehyde that is used extensively in mortuaries and pathology laboratories as a preservative and fixative.
Congress Orders a Review of These Findings by the Academy
In response to industry opposition, Congress directed the Department of Health and Human Services (HHS) to enlist the Academy to critique the 2011 RoC. Additionally, it directed the Academy to conduct an independent assessment regarding the carcinogenicity of formaldehyde.
Established in 1978, the National Toxicology Program is an inter-agency program run by HHS. The NTP is charged with coordinating, evaluating, and reporting on toxicology within public agencies, according to Wikipedia. It involves:
• The National Institutes of Health’s National Institute of Environmental Health Sciences (NIEHS, the administrative lead);
• The Centers for Disease Control and Prevention’s (CDC) National Institute for Occupational Safety and Health; and,
• The Food and Drug Administration’s (FDA) National Center for Toxicological Research.
The National Research Council Studied Key Issues
The NRC reviewed the NTP’s assessment to determine whether its conclusion was sufficiently supported by existing scientific data, according to its report titled, “Review of the Formaldehyde Assessment in the National Toxicology Program 12th Report on Carcinogens.” Specifically, the council’s mission was to determine:
1. Whether NTP had described and conducted its literature search appropriately;
2. Whether the relevant literature identified during the literature search was cited and sufficiently described in the background document;
3. Whether NTP had selected the most informative studies in making its listing determinations; and,
4. Whether NTP’s arguments supported its conclusion that formaldehyde is known to be a human carcinogen.
“The committee concludes that NTP comprehensively considered available evidence and applied the listing criteria appropriately in reaching its conclusion,” the NRC scientists wrote in their report. “The committee agrees with NTP’s conclusion, which is based on evidence published by June 10, 2011.”
Additionally, the NCR performed a Congressionally-mandated independent assessment of the draft United States Environmental Protection Agency (EPA) IRIS (Integrated Risk Information System) assessment of formaldehyde. NRC concurred with the EPA’s IRIS data and conclusions.
Pushback as Chemical Industry Tries to Put Findings into Context
“[I]t is important to note that formaldehyde can continue to be safely used,” stated Cal Dooley, President and CEO of the American Chemistry Council (ACC) in a news release. The ACC represents major U.S. chemical manufacturers. The ACC’s Formaldehyde Panel includes producers and users of formaldehyde, according to the release.
Some scientists responded strongly to the continued opposition of the ACC. “This NAS formaldehyde report . . . [is] the strongest possible statement from the scientific community,” declared Jennifer Sass, Ph.D., a senior scientist with the Natural Resources Defense Council (NRDC), on the NRDC staff blog. “[T]he chemical industry [opposition] added up to little more than a baseless defense of their toxic products,” wrote Sass.
Safety Officers at Medical Laboratories Want to Reduce Worker Exposure
Many pathologists, histotechnologists, and clinical laboratory managers are aware of ongoing efforts to better understand the risk of exposure to dangerous chemicals such as formalin, xylene, and toluene. Only a limited number of studies have been conducted and published about the risk of exposure to these chemicals by medical laboratory workers.
One such study was conducted in New Zealand and was reported by Dark Daily. The published study involved staff exposure to certain chemicals. Researchers determined that medical laboratory technicians who handle common solvents develop autoimmune connective tissue diseases in increased numbers.
The study was conducted at the University of Otago, in Wellington, New Zealand. Researchers asked all the histology laboratories and cytology laboratories in New Zealand to participate in the study. Notably, every laboratory department in the nation agreed and provided data and access to laboratory workers.
Study Found Histotechs at High Risk of Reynaud’s Phenomenon
The findings were published in the June 15, 2011, issue of Journal of Rheumatology. It offered credible evidence that clinical laboratory technicians, pathologists, and scientists who work with toluene and xylene double their chances of developing a vascular condition known as Raynaud’s phenomenon (RP). And for those who work with toluene and xylene combined with acetone or chlorinated solvents, the chance of developing severe RP increases by a factor of nine!
Because anatomic pathology laboratories have workers who frequently work with chemicals such as formalin, xylene, and toluene, health and safety managers at these labs are constantly working to both reduce exposure to these chemicals as well as develop work processes that eliminate the need to use such chemicals in processing and preserving specimens.
In recognition of studies that identify the cancer risk of exposure to such chemicals as formalin, xylene and toluene, some anatomic pathology vendors are developing products designed to minimize or eliminate the need to use such chemicals in the processing and fixing tissue. One company that was one of the first to introduce automated tissue processing systems that don’t require formalin and similar chemicals is Milestone Medical. It offers an automated tissue processing system that allows the operator to choose “formalin or formalin-free fixation” and “xylene or xylene-free clearing.”
Milestone Medical is among the first of the histopathology companies to recognize the demand by some histology laboratories for automated processing solutions that reduce the staff’s direct exposure to chemicals. In recognition of the strong interest that pathology laboratories have in cutting costs while improving safety, Dark Daily published a white paper about the use of vacuum-sealing technology in histology laboratories and operating theaters. The white paper, Advances in Pathology Tissue Management Reduce Formalin Use, Improve Quality and Cut Costs, is available for immediate download.
How quickly the anatomic pathology profession moves away from regular use of such chemicals as formalin, xylene, and toluene as a way to reduce worker exposure and keep them safer and healthier remains an open question. The use of these chemicals dates back to the origins of pathology with Rudolf Virchow, M.D. and his peers in the late 19th century and early 20th century. Even today, the contribution of these agents to sustained quality in the processing and preservation of lab specimens is widely-accepted.
—Pamela Scherer McLeod