Working in O&P: Protecting Yourself from Environmental Hazards
April 2009 Issue
"With the introduction of new technologies and techniques being applied regularly to the fabrication of artificial limbs, so too is the added exposure to potentially harmful compounds."
—Robert Kistenberg, MPH, CP, LP, FAAOP, "Exposure to Toxic Agents in Prosthetic Fabrication"
While the orthotics and prosthetics field is rapidly adding evidence-based knowledge, proven best practices, and post-graduate professionals, it is also fabricating its numerous products and devices in different ways and with different materials than it did in the past. New methods and materials most often result in superior techniques and devices, but they also bring with them new environmental and safety hazards. What are the present environmental and safety hazards that O&P technicians and clinicians could be exposed to, and what are the best practices being used to protect individuals from their harmful effects? This article will outline four phases of the fabrication process and the potential exposure to harmful compounds and/or hazards during each phase. The O&P EDGE also spoke with several O&P facilities and central fabrication facilities around the country to find out what safety practices and procedures they have implemented to keep their employees safe from harmful exposures.
Phase 1: Nuisance Dust from Model Acquisition and Rectification
Cutting a negative model and shaping a positive model creates nuisance dust, which the Occupational Safety and Health Administration (OSHA) defines as "dust that contains less than 1 percent quartz." In contrast to fibrogenic dust such as asbestos, which is biologically toxic, OSHA says that nuisance dust "has a long history of having little adverse effect on the lungs." However, this is not to say that the potential for harm is nonexistent. The degree of harm caused by dust depends upon four factors: composition, concentration, particle size and shape, and exposure time. Depending upon an individual's immune system response, the build-up of dust in the lungs can cause an adverse reaction. The good news, according to OSHA, is that "any reaction that may occur from nuisance dust is potentially reversible."4 On the other side of the spectrum, fillers, which are typically used to make the positive models lighter, contain crystalline quartz silica, which is a known human carcinogen.1
Julie McCay, CP, LP, of Scheck & Siress Prosthetics, Orthotics & Pedorthics, Oak Park, Illinois, whose resident research paper "Safety in the Prosthetics Workplace" won the American Academy of Orthotists and Prosthetists (the Academy) 2001 Best of the Resident Research Series, highlights various options available for businesses to control their dust. "To test particulate levels in your facility, you may need to contact a safety and health professional or an industrial hygienist," McCay suggests. "For the prosthetic and orthotic field, an air-purifying respirator is recommended. Filters—which should be class 95 or 100 particulate filters—remove particulates from the air, and chemical cartridges remove vapor and gases from the air. A combination half-face-mask respirator that has both filters and cartridges is recommended. However, if there are no chemical contaminants in the air, a particulate respirator may be appropriate."
Tom DiBello, CO, FAAOP, owner of Dynamic Orthotics and Prosthetics, Houston, Texas, cites fine particulate dust among the top four exposure risks he sees in his facility. To control the dust in large areas, DiBello had his lab fitted with an HVAC system large enough to filter the entire air volume every few minutes. For areas with more concentrated dust hazards, such as the grinding machine area, Dynamic has a point-of-capture system, which carries the dust away directly. DiBello notes that fumes, contact with chemicals, and noise exposure are also high on his list of concerns for his employees.
Phase 2: Chemical Fumes from Diagnostic Socket Fabrication
There is an even greater chance for exposure to toxic fumes during the second stage of the fabrication process—fabricating the test socket. Heated plastics not only pose a risk for thermal burns, but substances heated above their forming temperature may also create volatile emissions. The process of removing the plaster from the diagnostic socket creates debris and dust. According to Robert Kistenberg, MPH, CP, LP, FAAOP, coordinator of prosthetics for the Georgia Institute of Technology (Georgia Tech) master of science in prosthetics and orthotics (MSPO) program, the "gunking" process results in the risk of exposure to styrene monomers and vinyl ester resin, both of which are known carcinogens.
"Its vapors can reach excessive concentrations with a single exposure, causing a narcotic or anesthetic effect. Repeated excessive exposures may adversely affect the central nervous system or irritate the liver, kidneys, eyes, or respiratory tract." Epoxy resin hardeners contain elements that are "possible tumor promoters and may act as mutagens."1
According to McCay, 3M manufactures personalized air-quality monitors that you can wear and then send back to the company for analysis of exposure. Analysis is made via "gas chromatography to determine the concentration of the chemical in the air (PPM)," McCay says. In addition, McCay's team at Scheck & Siress recently moved to a facility that has a glue hood. "Everybody has gotten a good idea of what we used to smell and what we...smell now," she says, noting the extreme air-quality improvement. DiBello added, "We eliminated the use of toluene-based cleaners and strictly use acetone. This is not completely safe, but it is much safer than the toluene solvents."
To battle the potential effect of bonding emissions, Séamus Kennedy, BEng (Mech), CPed, president and co-owner of Hersco Ortho Labs, New York, New York, installed a carbon-activated internal-air-circulation system that continuously cycles the volume of air in the lab to eliminate the dust and volatile organic compounds (VOCs) that are emitted from many of the solvents used in Hersco's fabrication processes. Kennedy also points to the 20-ft.-high ceilings as a positive step toward eliminating the build-up of fumes in his central fabrication laboratory. To combat dust build-up, Kennedy says, "A good vacuum system is beneficial for individuals and good for our machines."
Phase 3: Noise Hazards from Diagnostic Prosthetic Fitting
Socket fitting requires numerous adjustments to achieve a perfect fit—adjustments that are often made by grinding plastics and pads. Not only does grinding produce more nuisance dust, but it also—and perhaps more importantly—introduces a noise hazard. To put noise hazards in perspective, normal conversations are held at 60 decibels, shouting in an ear registers at 110 decibels, and noise from jack hammering and power drilling can reach 130 decibels. According to McCay, hearing damage can occur when a person is exposed to noise levels of 85 decibels for eight hours—essentially one work day. With the use of grinding machines, riveting tools, and hammering, plus jackhammers to break out casts, the decibel levels in a fabrication facility can be dangerously loud for workers and patients alike.
A simple tool such as a digital sound-level meter can be purchased for around $50 in most electronics stores and is an invaluable tool to help an office determine the level of sound protection needed for its workers and guests. Many types of hearing protection are available. McCay recommends consulting with a hearing-protection supplier to determine the most appropriate hearing protection for your employees.2
Phase 4: Definitive Socket Fabrication and Cosmetic Finishing
Once all of the adjustments have been made and the test socket has been approved for comfort, the definitive socket is fabricated, which exposes the technician/clinician to the same gauntlet of chemical fumes, dust, and noise hazards outlined in phases one through three. Providing safety policies, procedures, and equipment is vital to the success and health of those who work in and visit an O&P facility, but unless compliance is also a priority, these tools become little more than wall adornments.
It is no secret that for some, working in O&P involves exposure to harmful compounds and other hazards, but Keith Crownover, CPO, of Crownover CPA, Bethany, Oklahoma, cautions against overemphasizing the hazards of working in the O&P field, stating that such an approach might make the field seem "horrific" or "life threatening." "We don't want to scare off...potential professionals," he says. He is, however, a strong proponent of promoting daily safety compliance. Crownover is also a passionate advocate for making public the small- and large-scale changes that can be made in the O&P work environment to prevent acute and chronic illnesses. "Become educated and knowledgeable about the materials being used and the ventilation and protection wear available," he says, "and require proper ventilation and environmental protection within labs in order to receive and maintain accreditation and in order to receive and maintain a CMS number."
Crownover, who is experiencing health problems that are potentially related to working in the field, also notes that old habits of tending toward shortcuts and convenience can be hard to break.
Michael Angelico, CPO, Advanced O&P Solutions, Hickory Hills, Illinois, is also a big proponent of safety compliance. To increase compliance at his company, Angelico has implemented disciplinary measures. "We have disciplinary procedures [for those who] don't follow safety procedures," he says. "The dust-collection system is [loud], plus you have a router, plus you have a piece of plastic you are grinding into—it's like an airport. We've seen in our industry the traumatic injuries that can happen.... We take every effort to protect [our employees] while they are here."
While it's important for employees to follow the safety policies and procedures that are in place at their company, employers are responsible for creating a safe working environment. OSHA requires all manufacturers of hazardous chemicals or products to supply material safety data sheets (MSDS) to all purchasers of their products.2 Employers, in turn, are lawfully required to post these data sheets in a public area. A workforce armed with knowledge will be better prepared to proactively address potential hazards and act quickly in the unlikely event a dangerous exposure occurs.
Our newest techniques and materials create increasingly resilient sockets, epoxies, and resins that cure quicker and result in lighter positive models, but our understanding of whether or not these changes pose new health risks should be just as up-to-date. Applying this knowledge and adhering to safety measures must be just as progressive. Enhancing workplace safety need not be extensive or expensive. Simply introducing the use of chemical gloves during the workday could significantly minimize the danger of a number of chemical hazards. During job interviews, those seeking employment at an O&P facility should question each facility concerning their safety standards and procedures and factor that into consideration when weighing employment options. Likewise, O&P facility owners can use their commitment to safety in the workplace as a way to attract the best and the brightest employees.
- Kistenberg RS. Exposure to Toxic Agents in Prosthetic Fabrication. Unpublished manuscript.
- McCay JA. Safety in the Prosthetics Workplace. Resident Research Project, January 2001.
- Office of Radiation, Chemical & Biological Safety (ORCBS). www.orcbs.msu.edu/occupational/programs_guidelines/respiratory_program/dust_mask_information.pdf. Accessed February 16, 2009.
- United States Department of Labor: Occupational Safety and Health Administration. Chapter 1: Dust and Its Control. www.osha.gov/sltc/silicacrystalline/dust/chapter_1.html. Accessed February 19, 2009.