1. Sterilant chemicals are highly toxic
Low temperature and liquid chemical sterilants are designed to kill all microorganisms including resistant spores and if they were not toxic, they would not be effective in sufficiently high concentration to destroy all microbial life including the chemically resistant sporicidal forms of certain bacteria. There are two main classes of sterilant chemical, the oxidizing agents such as hydrogen peroxide and peracetic acid and the alkylating agents such as ethylene oxide. The oxidizing agents destroy the cell wall and alkylating agents bind to proteins and DNA within the cell preventing their function. Needless say, these chemicals pose a significant risk to anyone who is exposed to them at high concentrations and even small leaks or exposures can have significant impact on health.
2. Sterilants pose serious health risks if exposed.
Hospital acquired infections (HAIs) are of major concern in the healthcare today. Every year nearly two million hospital-acquired infections claim roughly 100,000 lives and add $45 billion in costs., Healthcare is focused on placing patient safety and infection control as the paramount concern; however, much less emphasis has been placed on worker safety, the people who spend every day in this environment. The NIOSH National Occupational Research Agenda (NORA) report on the Healthcare sector commented that:
HCSA [healthcare and social assistance] workers are also at increased risk for many of the types of adverse health effects potentially caused by hazardous chemical exposures, including cancer, adverse reproductive outcomes, and work-related asthma and dermatitis. Although a wide range of hazards exists, a key barrier to addressing them is the misconception that HCSA work is safer than other work involving exposure to chemical and physical hazards.
There have been many studies that have associated long term exposure of healthcare workers to even low concentrations of sterilant chemicals with a variety of problems including reproductive issues such as miscarriages, respiratory irritation and occupational asthma. While ethylene oxide is widely known to have been classified as a carcinogen by both the IARC and NTP, the hazards associated with the other common sterilants are less well known.
Exposure to glutaraldehyde, o-phthalaldehyde (OPA) and ethylene oxide are all found to increase occupational asthma in healthcare., Glutaraldehyde use has been banned in the United Kingdom because of the impacts on worker health and the loss of healthcare professionals from hospitals who leave the profession due to the symptoms of chemical exposure. While OPA has been widely touted as a safer alternative to glutaraldehyde, it is also a dialdehyde with similar chemical properties and there are reports of similar occupational exposure symptoms such as occupational asthma, and sensitization. A recent review of eight studies on endoscope reprocessing concluded that the majority of studies described respiratory and dermal effects from detergents and chemical disinfectants and that more work was needed to access whether the introduction of automated endoscope washers had reduced the worker exposure level as much as has been widely anticipated.
The harmless sterilant chemical is an oxy-moron, since sterilant chemicals must be effective against a wide range of life forms. These chemicals are essential to the delivery of safe and effective health care, but means must be implemented to ensure that they are used safely. Engineering controls such as automated washers and exhaust systems to reduce vapors, continuous gas monitors to ensure that the remaining vapors are at safe levels, and training of personnel on how to recognize over exposure and what to do in the event of a leak or other release of one of these sterilant chemicals are essential for their safe use.
3. Sterilizers and re-processors can and do malfunction
Some facilities have an industrial hygienist visit once a year and believe that their employees are safe from possible exposure to sterilant gases. The problem with this approach is that it assumes that if the sterilizers and other equipment were working normally yesterday, then they must be working normally today. Unfortunately, this assumption is often wrong. Modern sterilizers are designed to very high levels of engineering and their manufacture is also in state of the art facilities. However, any device can fail, especially if it has a few thousand cycles on it. Low Temperature sterilizers and liquid chemical processors can fail and leak hazardous chemicals.
Examples include a recent report from Japan showed that hydrogen peroxide sterilizers can leak over one hundred ppm hydrogen peroxide. The researchers measured several hundred ppm of hydrogen peroxide at the exhaust because of a failure in the exhaust system. The technical support group at ChemDAQ has received many reports of leaking sterilizers and associated equipment. For example one customer found that four new hydrogen peroxide sterilizers each emitted between 25 and 40 pm hydrogen peroxide each time the door was opened, about the time the operator would be reaching in to retrieve the load. This customer now opens the door and retreats until the hydrogen peroxide monitors shows that it is safe to empty the sterilizer.
ChemDAQ has also installed gas monitoring at several facilities that resulted in the system going into alarm immediately upon commission. In one case, the exhaust fan supporting an ethylene oxide sterilizer had been knocked out by a thunder storm, but no-one knew. In another case, a leaking exhaust duct between the ethylene oxide sterilizer and abator was found to be the cause of the alarm. Recently ChemDAQ was contacted by a customer who told them that a manufacturer’s service technician inadvertently left the sterilizer in service mode. At the next load, the cycle aborted and employees inadvertently opened the door releasing ethylene oxide into the room (door interlock not active in service mode).
There are many other cases where leaks of sterilant gas have occurred for reasons, failure of the sterilizer, failure of the engineering controls or as in this last case, plain old human error. The manufactures of the sterilization equipment go to great lengths to make the sterilizers as safe as possible, but releases of sterilant gases still occur. As discussed in more detail below, the two most common sterilant gases (ethylene oxide and hydrogen peroxide) have no odor until far above safe levels. Unless there is a continuous monitor in place, there is no way to know that it is safe to work there. Just as a car can sometimes suddenly fail and leave one stranded at the side of the road, so too can sterilization equipment fail. It is important to monitor for sterilant gases continuously and monitors are available for most of the sterilant gases used today. Measuring the sterilant gas once a year just does not protect employees.
4. Sense of smell is an unreliable method for detection
Our sense of smell developed to tell us what was good to eat and what we should stay away from and many people expect our sense of smell to protect us from harmful chemicals as well. Unfortunately, smell is not a good method for determining if a sterilant vapor is present at a safe concentration or not. Sterilant vapors such as ethylene oxide and hydrogen peroxide plasma or vaporized hydrogen peroxide have no smell until far above safe levels, for example the odor threshold of ethylene oxide is 430 ppm, compared to the OSHA permissible exposure limit (PEL) of 1 ppm calculated as an 8 hr Time weighted average (TWA). Hydrogen peroxide has almost no smell, and people typically first perceive it from the irritation caused by hydrogen peroxide on the eyes and respiratory systems.
Some liquid chemical sterilants, such as peracetic acid and ozone have a pungent odor but it is very difficult to tell whether the concentration is safe or not. Even for people with a normal sense of smell, there is a lot of variability in the odor threshold from one person to the next, and even the same person from day to day (anyone have a cold or allergies today?).
Many gases and vapors, such as ozone, are subject to olfactory fatigue, whereby prolonged exposure to the gas or vapor reduces the sense of smell over time; and even for those gases which do not chemically cause a dulling of the sense of smell, prolonged exposure to most odors results in a dulling of the perception of smell as our minds wander to more imminent concerns. Therefore a slow rise in the concentration of a gas with a distinctive odor from a low safe to a higher hazardous concentration may not detected by employees with a busy workload to complete.
Lastly, even if the gas or vapor is freshly smelt, how many of us can actually judge a concentration based on the smell. Generally, the sense of smell is not quantitative; the best we can usually do is to say that one concentration is greater than another. This sense if great for determining if a piece of fish is fresh, but not for determining if the peracetic acid vapor concentration exceeds 0.4 ppm. The only way to accurately measure the concentration of a gas or vapor over time is to have a continuous monitor designed for that gas or vapor. Continuous monitors are available for most of the sterilant gases and vapors including ethylene oxide, hydrogen peroxide and peracetic acid.
5. Employers have a legal duty to provide a safe work environment
The Occupational Safety and Health Act (OSH) of 1970 created a legal duty for employers to provide a safe work environment (sec. 5) and a legal duty for employees to follow all workplace safety standards.
SEC. 5. Duties
(a) Each employer —
(1) shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees;
(2) shall comply with occupational safety and health standards promulgated under this Act.
(b) Each employee shall comply with occupational safety and health standards and all rules, regulations, and orders issued pursuant to this Act which are applicable to his own actions and conduct
This clause, known as the General Duty clause, provides a catch all regulation that permits OSHA to prosecute employers with dangerous work areas even when there is no specific regulation. OSHA has also promulgated a number of occupational safety and health standards (generally in 29 CFR) which are intended to provide a regulatory framework for safe work practices.
From the perspective of chemical sterilization there are several standards which are applicable. The first is the air contaminants standard (29 CFR 1910.1000). This standard provides maximum PELs for specific compounds. For example, the PEL for hydrogen peroxide is 1 ppm calculated as an 8 hour time weighted average (TWA).
The Hazard Communication standard (29 CFR 1910.1200) is intended to inform employees about the hazards of the chemicals which they are using. The Hazcom standard involves labeling of chemicals, use of safety data sheets and especially training. The Hazcom standard was recently revised to improve worker understanding of the risk and conformity with the Global Harmonization System.
Certain chemicals, especially carcinogens, are not listed under the Air Contaminants standard, but instead have their own standards. Ethylene oxide (29 CFR 1910.1047) is an example of such a standard. The ethylene oxide standard includes PELs for ethylene oxide: 5 ppm excursion level calculated as a 15 minute TWA and 1 ppm calculated as an 8 hour TWA (same as hydrogen peroxide). The ethylene oxide standard also includes much of the hazard communication standard but tailored more specifically for ethylene oxide.
The air contaminants standard and the ethylene oxide standard are largely performance standards in that the standard sets the goal and leaves the means to achieve that goal up to the employer. This approach is taken to both avoid obsolescence inherent in specifying a technological means to an end, but also to give employers the flexibility to select the means best suited to their application. This flexibility is important since the same regulations apply to a hospital, a steel mill and water treatment plant, and clearly the best implementation of those regulations may differ from one industry to the next. To use the PELs as an example, the PEL for hydrogen peroxide is 1 ppm calculated as an 8 hour TWA; but the standard does not say how that goal is to be achieved. Since hydrogen peroxide is invisible and has no odor until well above safe levels, one employer may choose to modify the process to eliminate hydrogen peroxide but another may achieve this goal by adding ventilation and using a continuous monitor for hydrogen peroxide to determine if the PEL has been reached, and a third employer may provide full face respirators to their employees working in that area.
In another example, the ethylene oxide standard calls for:
“Alerting employees.” Where there is the possibility of employee exposure to EtO due to an emergency, means shall be developed to alert potentially affected employees of such occurrences promptly. Affected employees shall be immediately evacuated from the area in the event that an emergency occurs. [1910.1047(h)(2)]
The standard again sets the goal, but does not say how to achieve it. However, since ethylene oxide has no odor below ~400 ppm, and OSHA believes that 50 ppm would constitute a sufficient concentration to be an emergency, there is no practical method to detect an ethylene oxide leak and provide a prompt warning to employees without a continuous monitor.
6. OSHA, EPA and ACGIH have developed Occupational Exposure Limits to protect workers
Everyone knows that toxic gases are toxic, but at what concentration is the gas hazardous? In the US, the American Conference of Government and Industrial Hygienists (ACGIH) developed what later became the threshold limit values (TLVs) in the 1940s and regularly updated them as more data became available. There are now more than 700 chemicals and physical agents listed. The ACGIH sets its TLVs based on the best scientific information available. The ACGIH is a private organization and so its TLVs are not law, though the laws of some countries reference them directly.
In the US, OSHA can prosecute an employer under the General Duty clause (discussed above) using the relevant TLV as a threshold to indicate whether a work environment is free from “recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.” Similarly, a private individual could sue an employer (if not covered by workers compensation) under a negligence or gross standard using the TLV as an indication of the standard of care of a reasonable person.
In 1970, the OSHA was created under the OSHA Act and was charged with promulgating permissible exposure limits (PELs). The PELs are legal requirements and OSHA can prosecute an employer if it allow its employees to be exposed to a gas concentration greater than the PEL. The first PELs adopted in 1971 by OSHA were taken from the 1968 ACGIH TLVs since they had already been adopted as a federal standard as part of the 1969 Walsh-Healy Act revision. OSHA also recognizes that many of the PELs are out of date and that many compounds are now widely used that should have PELs, but OSHA’s resources for the development of PELs is limited.,
Where there is a PEL, it sets the legal standard for the maximum exposure that an employee may receive. For chemicals for which there is no PEL, them employers should look to other standards, such as the ACGIH TLVs, the NIOSH recommended exposure limits and EPA’s acute exposure guideline levels (AEGLs). Note: The AEGLs are not an occupational exposure limit (OEL) but instead are intended to assess the risk of a one-time exposure and so may be expected to be less conservative than an OEL since an OEL is usually for repetitive exposure over the normal workday.
For sterilant vapors such as hydrogen peroxide and ethylene oxide, there are OSHA PELs of 1 ppm calculated as an 8 hour TWA for both compounds and an additional 5 ppm excursion limit for ethylene oxide calculated as a 15 minute TWA. For glutaraldehyde, there is no OSHA PEL but OSHA recommends following the NIOSH REL of 0.2 ppm (8 hr TWA). Many of the compounds that were introduced as sterilants and high level disinfectants more recently than the 1970s have neither OSHA PELs not NIOSH RELs, but that does not mean that they are safe. A good example is peracetic acid, for which there is an EPA AEGL of 0.52 mg/m3 or 0.17 ppm (TWA 10 min to 8 hours). The ACGIH has proposed a TLV for peracetic acid of 0.4 ppm (calculated as a 15 min TWA), the lower TLV than hydrogen peroxide (1 ppm *hr TWA) reflects the stronger oxidizing properties of peracetic acid and less protective inhibition by the catalase enzyme. Other now common compounds such as OPA have no exposure limits, but are undoubtedly toxic (otherwise they would function well as a sterilant).
OSHA recognizes the risks that healthcare workers face:
“Healthcare workers face a number of serious safety and health hazards. They include bloodborne pathogens and biological hazards, potential chemical and drug exposures, waste anesthetic gas exposures, respiratory hazards, ergonomic hazards from lifting and repetitive tasks, laser hazards, workplace violence, hazards associated with laboratories, and radioactive material and x-ray hazards. Some of the potential chemical exposures include formaldehyde, used for preservation of specimens for pathology; ethylene oxide, glutaraldehyde, and paracetic acid [sic] used for sterilization; and numerous other chemicals used in healthcare laboratories.”
It is important that employers ensure that their employees are not exposed to potentially hazardous concentrations of sterilant chemicals. If there is an OSHA PEL, then as a legal standard, the PEL must be followed, but employers should recognize that the standard may be obsolete and so should also check to see if other standards such as the ACGIH’s TLVs are more conservative. If they are, then the more conservative standard should be followed.
For those compounds without an OSHA PEL, the employer should follow the best standard from a reputable organization such as the NIOSH REL or ACGIH TLV. If no standards are available, then the employer should seek guidance from other sources such as the chemical manufacturer about their recommended exposure levels or consult other safety publications or professionals.
Once an occupational exposure limit has been determined, it is important to ensure that employees are not exposed beyond this limit. As discussed elsewhere in this article, continuous gas monitors provide the best means for protecting employees from over exposure to hazardous gases and vapors.
7. OSHA’s hazard communication Standard requires that employers tell employees how they can detect when a leak occurs–
The hazcom standard reads:
Training. Employee training shall include at least:
Methods and observations that may be used to detect the presence or release of a hazardous chemical in the work area (such as monitoring conducted by the employer, continuous monitoring devices, visual appearance or odor of hazardous chemicals when being released, etc.);
The physical, health, simple asphyxiation, combustible dust, and pyrophoric gas hazards, as well as hazards not otherwise classified, of the chemicals in the work area;
The measures employees can take to protect themselves from these hazards, including specific procedures the employer has implemented to protect employees from exposure to hazardous chemicals, such as appropriate work practices, emergency procedures, and personal protective equipment to be used; …, [1910.1200(h)(3)]
Many of the sterilant chemicals used today to sterilize temperature sensitive medical devices are imperceptible to human senses until at concentrations well above dangerous levels and even those that are perceptible are not quantifiable by smell. Therefore, it is important to have an automatic means to detect the presence of the sterilant gas in the even that it escapes from the sterilizer or associated equipment.
By their very nature, leaks are unpredictable since the predictable leaks will prevented by good design and preventative maintenance. While modern sterilizers are made to the highest standards, any equipment can and sometimes does fail and so a continuous gas monitor is necessary in order to alert employees in the event of a sterilant gas or vapor leak.
Some facilities believe that they are protecting their people by means of exposure badges, but these devices do little to prevent exposure. A typical badge will be worn by an employee for eight hours and then sent to a laboratory for analysis. When the results come back, the employee will learn whether they were exposed to the sterilant gas or not. The badge provides no warning of current exposure and in the event of a major leak would simply provide a record of how large the exposure was.
However, most facilities do not badge continuously either, instead choosing to perhaps badge every six months. Therefore, when the results come back, the employee will be informed that they have been exposed to sterilant gas of X ppm hours during a given 8 hour shift and perhaps that much every day up to six months prior. The badges simply document prior exposure for hospital records, and provide evidence for law suits etc., may induce a false sense of security, but provide very little protection
In order to adequately protect workers using sterilant gases or vapors, it is necessary to use a continuous monitor for that gas. Sometimes leaks slowly build up over time, but other leaks occur suddenly without prior warning. If the facility is using gas monitors, then as soon as the gas or vapor concentration reaches hazardous levels, the employees can react to either mitigate the problem or leave the area. If they leave the area, the gas monitors will tell them when it is safe to return. Unlike badges, continuous gas monitors prevent employees from being exposed.
8. Mitigate risk of litigation, OSHA fines
Under the OSH Act of 1970, OSHA is tasked with enforcing occupational safety laws. OSHA may conduct random inspections of workplaces, it can act in response to an employee or other complaint about work practices or it can visit following a reportable incident.
In the last five years, OSHA has conducted 1931 inspections of General Medical and Surgical Hospitals (SIC = 8062). According to the American Hospital Association, there are 5,724 registered hospitals in the US and thus on average, each hospital can expect be inspected by OSHA once every 15 years. In practice, some hospitals will have been inspected more frequently than this number as a result of employee complaints, prior history of non-compliance etc, and conversely the ‘good’ hospitals may be inspected less frequently.
If OSHA discovers non-compliance during an inspection they may issue warnings or fines, the magnitude depending on the severity and frequency of the infraction. All OSHA fines are public information and many facilities fear the bad publicity of an OSHA fine more than the financial impact. Obviously creating a safe work environment is key to avoiding OSHA fines.
The penalties are set out in section 17 of the OSH Act.:
(a) Any employer who willfully or repeatedly violates the requirements of section 5 of this Act, any standard, rule, or order promulgated pursuant to section 6 of this Act, or regulations prescribed pursuant to this Act, may be assessed a civil penalty of not more than $70,000 for each violation, but not less than $5,000 for each willful violation.
(b) Any employer who has received a citation for a serious violation of the requirements of section 5 of this Act, of any standard, rule, or order promulgated pursuant to section 6 of this Act, or of any regulations prescribed pursuant to this Act, shall be assessed a civil penalty of up to $7,000 for each such violation. …
Employers should take steps in order to reduce the risks of employee injury or an OSHA penalty.
- Review the workplace for safety and compliance with the relevant OSHA standards. These should include general safety, fire and emergencies as well as special safety procedures to be followed specific to the operation, such as use of chemicals. Ensure employees are trained on all relevant procedures.
- Develop a written safety plan (e.g. emergency action/fire prevention plan under 29 CFR 1910.38-39; Hazcom plan 1910.1200) and train their employees about the plan. The plan should be site specific, so for example if the facility uses ethylene oxide for sterilization, the plan should state how a leak will be detected, how employees should respond if a leak occurs, when to evacuate, and how will they know when it is safe to return.
- Ensure that the necessary equipment is available and employees have had the appropriate training to use it. The equipment includes engineering controls (ventilation and exhausts), personal protective equipment and gas monitors to detect gas leaks and to tell workers when it is safe to return.
- Perform regular inspections of the work area and ensure that safe practices are performed. The routine inspection of safety equipment is essential for their correct operation in case of an emergency. Inspections may include flushing eye wash stations, calibration/sensor exchange of gas monitors, checking air flow in exhaust ducts etc. Ensure that employees are regularly trained on the safety procedures applicable to the facility.
9. Reduce lost work days
Exposure to chemical sterilants high level disinfectants can result in lost work days if workers become sick or injured, high turn over costs as workers look for safer employment and higher workers compensation rates if workers make a claim following injury from over exposure.
According the Bureau for Labor Statistics, in 2010, the injury and illness rate for health care support workers increased 6 percent to 283 cases per 10,000 full-time workers, almost 2 1/2 times the rate for all private and public sector workers at 118 cases per 10,000 full-time workers. Assistant Secretary for the department’s Occupational Safety and Health Administration Dr. David Michaels issued the following statement in response:
“It is unacceptable that the workers who have dedicated their lives to caring for our loved ones when they are sick are the very same workers who face the highest risk of work-related injury and illness. These injuries can end up destroying a family’s emotional and financial security. While workplace injuries, illnesses and fatalities take an enormous toll on this nation’s economy – the toll on injured workers and their families is intolerable.”
The NORA report discussed above suggested part of the reason why there is such as high rate of injury in the healthcare sector:
The HCSA sector is burdened by the historical and entrenched belief that patient care issues supersede the personal safety and health of workers and that it is acceptable for HCSA workers to have less than optimal protections against the risks of hazardous exposures or injuries. Because patients and providers share the healthcare environment, efforts to protect patients and providers can be complimentary, even synergistic, when pursued through a comprehensive, integrated approach. 
Employee safety is not contradictory to patient safety. The Joint Commission recently published a monograph focusing on the synergy between patient safety and employee safety, including case studies in a number of healthcare situations. According to Hospital & Health Networks, more than 250,000 health care workers are injured every year at work, and more than $20 billion is spent each year on worker’s compensation costs. The cost of worker safety is often recouped through better performance and less days of missed work. It is likely that if more investment were made in worker safety, the decrease in costs would more than pay for these investments. The same in true in most industries; most executives polled by Liberty Mutual said that for every $1 their company spent on workplace safety, they saved at least $3. In a recent poll of financial decision makers the participants perceived that on average for every dollar spent improving working place approximately $4.41 would be returned. The primary goal of healthcare is patient safety, but patient care cannot be successful absent the safety of healthcare workers.
10. Show workers that they are valued employees and that their safety and health is a top priority
Sterile processing is becoming increasingly complex and the costs of frequent employee turnover are often overlooked. Processing hundreds of types of instruments with very similar characteristics requires an extensive learning curve on the part of employees. In a 2008 survey, respondents indicated that it took between 3 to 12 months to train a sterile processing technician and that most employers spend two to three moths working with new employees with a training cost of over $40,000 (at 2008 $).
This sentiment was echoed by Nyla “Skee” Japp, president of the American Society of Healthcare Central Service Professionals who said that”
“I believe that the greatest challenge facing central service departments throughout the nation is turnover of staff.”
He went on to say:
“I see the constant turnover of staff as a waste of money. Training that is required for a CS/SPD technician costs a lot of money when the training is done correctly. The problem a manager faces by not training staff and having the staff understand the sterilization process is that the problems will continue on up to the patient, not to mention the customer service to the OR and surgeon.”
If employees feel valued then they will perform better and are much less likely to change jobs. Feeling appreciated is a strong motivator in the workforce, as significant as monetary rewards. An employer who fails to train their employees about how to work safely, fails to provide the engineering controls, continuous monitors and other measures to keep their workforce safe will not enjoy the respect and appreciation of their workforce and will face issues of retention, employee dissatisfaction and low motivation.