Occupational Health: Protecting Workers Against Chemical Exposures

By Kelly M. Pyrek

The Occupational Safety and Health Administration (OSHA) says that more U.S. workers are injured in the healthcare industry than any other. This sector has one of the highest rates of work-related injuries and illnesses, and in 2010, it reported 653,900 injury and illness cases. Also for that year, the latest year for which data are available, OSHA says the incidence rate for work-related nonfatal injuries and illnesses in healthcare was 139.9; by comparison, the incidence rate for nonfatal injury and illnesses in all private industry was 107.7. That's a lot of injuries and illness despite the fact that the General Duty Clause of the legislation that created OSHA requires employers to provide workers with a safe workplace that does not have any known hazards that cause or are likely to cause death or serious injury.

Healthcare professionals, especially those working in surgical services, environmental services and sterile processing, are exposed to a significant number of chemicals including those used to clean and disinfect the healthcare environment and those used to disinfect and sterilize surgical instruments and medical device. Other hazards include bloodborne pathogen transmissions caused by sharps injuries, as well as respiratory dangers associated with the inhalation of surgical smoke and other particulates.
The delterious health effects of chemical exposures to healthcare workers have been the focus of a number of studies in the literature. let's take a look at some aspects of common occupational health hazards, especially respiratory and chemical exposures.

Respiratory exposures are a continual challege. Surveillance data from four U.S. states found that work-related asthma among healthcare workers  represented 16 percent of total reported cases, exceeding their representation in the general workforce (Pechter, et al. 2005).

Delclos, et al. (2007) evaluated occupational risk factors for asthma in physicians, occupational therapists, nurses and respiratory therapists. A detailed questionnaire was mailed to a random sample (5,600) of all Texas physicians, nurses, respiratory therapists, and occupational therapists with active licenses in 2003. Information on asthma symptoms and nonoccupational asthma risk factors obtained from the questionnaire was linked to occupational exposures derived through an industry-specific job-exposure matrix. The final study population consisted of 3,650 professionals -- 862 physicians, 941 nurses, 968 occupational therapists and 879 respiratory therapists. Reported asthma was associated with medical instrument cleaning, general cleaning, use of powdered latex gloves between 1992 and 2000, and administration of aerosolized medications. The risk associated with latex glove use was not apparent after 2000. Bronchial hyperresponsiveness-related symptoms were associated with general cleaning, aerosolized medication administration, use of adhesives on patients, and exposure to a chemical spill. The researchers concluded that contribution of occupational exposures to asthma in healthcare professionals is not trivial, meriting both implementation of appropriate controls and further study.

As Delclos, et al. state, "This study found an approximately twofold increased likelihood of asthma after entry into a healthcare profession for tasks involving instrument cleaning and disinfection, general cleaning products used on indoor building surfaces, use of powdered latex gloves, and the administration of aerosolized medications. Significant associations were likewise found between bronchial hyperresponsiveness (BHR)-related symptoms and use of surface cleaners, aerosolized medication administration, adhesives, or solvents as products in patient care, as well as with a history of sustaining an acute exposure to a chemical or gas at work. Study findings are consistent with previously reported associations between asthma and occupational exposures in healthcare settings, and identify new relationships warranting further evaluation. The associations observed with a history of acute exposures to chemical spills or gas releases at work and with tasks involving use of respiratory irritants provide further support for irritant-induced asthma in this population."

Occupational exposure to chemicals is common and frequent in hospitals, but some researchers say that a significant portion of self-reported exposures are underestimated. In their study, Donnay, et al. (2012) observed a  large underestimation of self-reported exposure and measurement bias. Participants were interviewed on occupation with a specific questionnaire for hospital workers regarding tasks and cleaning/disinfecting agents. Two estimates of exposure were available: self-report and expert assessment. The expert assessment involved a standardized procedure to estimate intensity, frequency and probability of exposure for each job. The study focused on eight exposures: formaldehyde, glutaraldehyde, bleach/chlorine, alcohol, quaternary ammonium components, ammonia, sprays and latex gloves. In the survey of 1,571 adults, 176 hospital workers (327 occupations) with both self-reported and expert exposure assessments were studied. An underestimation of self-reported exposure was observed especially for formaldehyde (26.5 percent vs 32.7 percent), ammonia (7.4 percent vs 18.8 percent), alcohol (64.9 percent vs 93.0 percent) and quaternary ammonium components (16.6 percent vs 70.9 percent), compared to expert assessment.

Arif, et al. (2009) sought to identify occupational exposure risk factors associated with the development of new-onset asthma in nurses, and concluded that indeed, workplace exposures to cleaning products and disinfectants increased the risk of new-onset asthma. The researchers administered a cross-sectional survey to a sample of licensed Texas nurses (the response rate was 70 percent) and compared the responses to three other healthcare professional groups. Outcome variables were physician-diagnosed new-onset asthma after entry into the healthcare profession and symptoms associated with bronchial hyper-responsiveness (BHR). Occupational exposures were ascertained through a job-exposure matrix, grouped into four categories: cleaning-related tasks, use of powdered latex gloves, administration of aerosolized medications, and tasks involving adhesive compounds, glues and/or solvents.

After adjustment for age, sex, ethnicity, atopy, smoking, body mass index and seniority, Arif, et al. (2009) found that asthma was significantly greater among nursing professionals involved in medical instrument cleaning and exposure to general cleaning products and disinfectants. Use of powdered latex gloves during was associated with 1.6 times the odds of reported asthma. In univariate analysis, exposure to adhesives, glues and/or solvents was associated with a twofold increase in the odds of reported asthma, but not after adjustment for covariates. Similarly, the odds of BHR-related symptoms were significantly greater among nursing professionals exposed to general cleaning products and disinfectants and adhesives, glues and/or solvents used in patient care.

A detailed characterization of exposures to cleaning products among U.S. hospital cleaning staff was reported by Bello and Quinn (2009). They conducted workplace interviews, reviews of product Materials Safety Data Sheets and the scientific literature on adverse health effects to humans, reviews of physical/chemical properties of cleaning ingredients, and occupational hygiene observational analyses. They classified cleaning tasks into different exposure categories, a strategy that can be employed by epidemiological investigations of the impact of cleaning on health, and concluded that a combination of product evaluation and workplace exposure data is necessary to develop strategies for protecting workers from cleaning hazards. 

Bello and Quinn's study  identified cleaning products' ingredients of concern with respect to respiratory and skin irritation and sensitization; and assessed the potential for inhalation and dermal exposures to these ingredients during common cleaning tasks such as floor cleaning, mirror cleaning, toilet bowl cleaning, counter cleaning and floor-finishing tasks.

Bello and Quinn (2009) found that the products used for common cleaning tasks were mixtures of many chemicals, including respiratory and dermal irritants and sensitizers. Examples of ingredients of concern included quaternary ammonium compounds, 2-butoxyethanol, and ethanolamines. Cleaning workers are at risk of acute and chronic inhalation exposures to volatile organic compounds (VOC) vapors and aerosols generated from product spraying, and dermal exposures mostly through hands. The researchers explain that in their study, an ingredient was considered to be of concern if it occurred frequently in multiple cleaning products; it was likely to cause respiratory and skin irritation and sensitization;  it occurred at higher concentrations compared to other ingredients in the product; or had higher potential to become airborne compared to other mixture ingredients.

The researchers divided the exposure intensity into low, medium and high categories. Tasks classified in the low-exposure category include floor cleaning tasks. As Bello and Quinn (2009) explain, "Floor cleaning generates low concentrations of VOC in the air, mainly because floor products were more diluted compared to other products. Because quaternary ammonium compounds, an important group of chemicals of concern in floor cleaning products, are not volatile chemicals, the potential for their inhalation during floor cleaning is low. Additionally, because floor cleaning does not involve product spraying, the risk of inhalation to aerosol particles is low. Despite their longer duration compared to other tasks, considering their lower exposure intensity, floor cleaning tasks can be classified in the low inhalation exposure category."

Tasks classified in the medium-exposure category include: window and mirror cleaning, sink cleaning, counter cleaning, and toilet bowl cleaning. As Bello and Quinn (2009) explain, "The potential for inhalation exposures during these tasks is higher compared to floor cleaning tasks because: a) the intensity of VOCs of concern in the air is higher due to higher concentrations of volatile ingredients in the diluted products and b) product spraying may facilitate exposures to aerosols and other non-volatile ingredients, such as quats, commonly found in products used for these tasks. Workers performing these tasks are continuously exposed to VOCs and aerosols during the workday."

Tasks classified in the high-exposure category included  "combination tasks" which include patient room and bathroom cleaning tasks. As Bello and Quinn (2009) explain, "Due to the continuous application of many products one after another, the potential for inhalation exposures can be higher compared to when the tasks are performed separately. [These] tasks potentially generate higher airborne exposures. Because these tasks are done in small volume environments, it is possible that airborne VOC can increase rapidly in a short period of time exposing the worker to inhalation risks."

The potential for dermal exposure from these tasks was also studied by the researchers. They note, "According to the DREAM categories, cleaning tasks create moderate (such as in floor cleaning tasks) and high potential for dermal exposure (such as in mirror/window cleaning, sink cleaning and toilet bowl cleaning tasks). We identified the relative contribution of three dermal exposure routes for different tasks ... the 'emission' route contributes more to the overall exposure compared to 'transfer' and 'deposition' routes during mirror and toilet bowl cleaning. One possible explanation to this finding is related to the spraying activities that generate liquid particles with aerodynamic diameter >100 m that potentially reach the skin. In the case of sink cleaning, the 'emission' is lower because the potential for aerosol particles to reach the head and upper body parts here is lower compared to mirror and toilet bowl spraying. Transfer contributed more during floor cleaning, probably due to the continuous hand contact with the mop handle contaminated with cleaning solution. Overall, floor cleaning tasks were associated with the lowest potential for dermal exposures. Hands were identified as having the highest potential for dermal exposure for most of the tasks. Forearms were at the next highest risk of exposure during sink, toilet bowl and mirror cleaning while for floor cleaning, feet and lower legs were most prone to exposure."

From their study, Bello and Quinn (2009) established the following:

- Cleaning products contain complex mixtures of many chemicals that have a very wide range of volatilities and other chemical properties. They suggest, "When investigating ingredients using product MSDSs, health and safety professionals should review not only MSDSs of concentrated product forms, but also the ready to use forms. We found that many ingredients reported in the concentrated form were missing in the RTU form, because MSDSs are required to list only ingredients at concentrations greater than 1 percent in the product. This is important for identifying ingredients that are sensitizers in the workplace; given the fact that sensitization may occur even at trace concentrations."

- There is evidence of exposures to respiratory and dermal irritants and sensitizers from cleaning products. The researchers emphasize that "Quantitative workplace investigations are necessary to measure the degree of exposure intensity and relationship with irritation symptoms reported among cleaning workers."

- Cleaning tasks generate airborne exposures, and that volatile compounds identified in cleaning products covered a wide range of volatilities, from highly volatile ingredients such as ammonia and isopropyl alcohol, and relatively less volatile ingredients such as 2-butoxyethanol and mono-ethanolamine. As the researchers observe, "The worst exposure scenarios can happen when several cleaning tasks are performed in small and poorly ventilated spaces, such as bathrooms."

- Cleaning tasks create potential for dermal exposures, and that for all cleaning tasks, hands are at higher potential for dermal exposure compared to other body parts. As the researchers note, "Overall, our results suggest that dermal exposure prevention should focus mostly on hands and the activities that involve product spraying... The DREAM observational analyses applied here showed that dermal exposure can be an important route for chemicals in the body. Recent literature suggests that some chemical ingredients may be able to penetrate the skin and cause systemic respiratory effects. Dermal exposure should be evaluated in future studies of health effects of cleaning."

- Cleaning exposures are a function of the way that tasks are performed, as well as product formulations. As Bello and Quinn (2009) add, "A comprehensive approach to exposure prevention will account for the method with which a product is applied and the task requirements, as well as assessing of the chemical ingredients and implementation of safer alternatives to cleaning products."

Bello and Quinn's findings underscore the importance of minimizing occupational exposure to chemicals through the use of proper cleaning protocols as well as donning personal protective equipment (PPE). It is also critical to control exposures at the source, during a cleaning process and at the point of the worker's tasks, in order to keep healthcare workers and patients safe.

Kent L. Miller, MHL, CHESP, director of environmental services at Jackson Hospital & Clinic in Montgomery, Ala., says that some of the specific measures and recommended practices that his facility has found to be effective include not using spray bottles and always using proper PPE.
"Glove and goggle use [is critical] when pouring or dispensing chemicals, and workers with allergies should wear masks," Miller says. "If they dont don goggle and masks (where appropriate) they should sign off that they have been told of the dangers, or  they sign off at employment agreement to don them." Miller also emphasizes the importance of proper MSDS posting as well as training as part of the OSHA Right to Know. He recommends that environmental services professionals consult the Association for the Healthcare Environment (AHE)s Practice Guidance for Healthcare Environmental Cleaning (second edition) as well as AHE Recommended Practice: Carts, Closets, Equipment and Supplies.

PPE is also mandated by a number of Occupational Safety and Health Administration (OSHA) standards:

- OSHA standard 1910.132(a) says that, "Protective equipment, including personal protective equipment for eyes, face, head, and extremities, protective clothing, respiratory devices, and protective shields and barriers, shall be provided, used, and maintained in a sanitary and reliable condition wherever it is necessary by reason of hazards of processes or environment, chemical hazards, radiological hazards, or mechanical irritants encountered in a manner capable of causing injury or impairment in the function of any part of the body through absorption, inhalation or physical contact."

- OSHA standard 1910.132(d)(1) says that, "The employer shall assess the workplace to determine if hazards are present, or are likely to be present, which necessitate the use of personal protective equipment (PPE). If such hazards are present, or likely to be present, the employer shall: Select, and have each affected employee use, the types of PPE that will protect the affected employee from the hazards identified in the hazard assessment; communicate selection decisions to each affected employee; and select PPE that properly fits each affected employee

- OSHA standard 1910.132(d)(2) says that, "The employer shall verify that the required workplace hazard assessment has been performed through a written certification that identifies the workplace evaluated; the person certifying that the evaluation has been performed; the date(s) of the hazard assessment; and, which identifies the document as a certification of hazard assessment."

Training on proper PPE use is also mandated by OSHA. OSHA standard 1910.132(f)(1) says that, "The employer shall provide training to each employee who is required by this section to use PPE. Each such employee shall be trained to know at least the following: when PPE is necessary; what PPE is necessary; how to properly don, doff, adjust, and wear PPE; the limitations of the PPE; and the proper care, maintenance, useful life and disposal of the PPE. Additionally, OSHA standard 1910.132(f)(2) says that, "Each affected employee shall demonstrate an understanding of the training specified in paragraph (f)(1) of this section, and the ability to use PPE properly, before being allowed to perform work requiring the use of PPE."

"Environmental services professionals train their staff on proper use of chemicals and the use of PPE," says Miller. "In 'Management by Walking Around' practice, any violation of this brings one-on-one training by the supervisor, manager or director. The use of gloves for all cleaning is preferred and expected of all staff. This helps alleviate an dermal issues. Most healthcare institutions have or are working on eliminating the use of latex products; this has been occurring for several years. All of the healthcare organizations that I have worked at have eliminated latex gloves."

According to Delclos, et al. (2007), "In the 1990s, attention began focusing on respiratory hazards among healthcare workers, partly because of increasing concern over occupational latex allergy after passage of the 1992 Occupational Safety and Health Administration (OSHA) bloodborne pathogens standard, which resulted in a significant increase in the use of latex-containing personal protective equipment, such as powdered latex gloves. However, potential asthmagens in healthcare settings go beyond latex, and may include disinfectants and sterilants (e.g., glutaraldehyde, formaldehyde), pharmaceuticals (e.g., psyllium, antibiotics), sensitizing metals (e.g., in dental alloys), methacrylates, irritant aerosolized medications (e.g., pentamidine and ribavirin), and cleaning products."

One way to control and cut down on chemical-related occupational hazards and exposures is to explore alternatives to harsh chemicals. Bello and Quinn (2009) note that, "Given the uncertainty of disinfectant effectiveness in cleaning public areas, the risk of inducing bacteria resistance, and the health concerns related to the use of disinfectants, it is critical to further evaluate disinfectants' effectiveness for common cleaning activities and to develop workplace strategies for preventing workers from exposures to disinfectants. Such strategies may include purchasing of green cleaning products, identification of the areas where disinfection is needed, and following the necessary disinfection procedures in the cases when disinfection is necessary."

Miller acknowledges that the very chemicals that can help control hospital pathogens can pose dangers to the staff who handle them: "Bleach is necessary to use for C. difficile disinfecting, however it can cause respiratory issues with some staff, patients or visitors," he says. "Quaternary ammonium (quats) products have not been shown to create huge concerns; most are generally not that strong in odor or are destructive to the environment. Quats can build up on surfaces so there is a necessity to deep-scrub these surfaces on a scheduled basis. Phenolics can be a concern, just as bleach is. They cannot be used in nursery areas or where newborns are placed. They are also very destructive to surfaces. I have seen cases of phenolics removing floor finishes, etching stainless steel, and etching countertop surfaces."

Some advocate for safer, green cleaners, but the jury is out on how effective they are against hospital pathogens. "I am a firm believer in using sustainable products as much as you can," Miller says. "In fact, 60 percent of the products we use in our healthcare organization is sustainable. However I cannot see that a product that is sustainable, can also be effective against hospital pathogens. We need to be sure to kill all pathogens with hospital-approved disinfectants."

As the Massachusetts Nurses Association suggests in its position statement on "Exposure to Environmental Cleaning Chemicals in Healthcare Settings," healthcare facilities should seek alternatives to harsh chemicals when possible, because as an increasing number of  manufacturers and distribution companies recognize the problems associated with occupational and environmental exposure to chemical toxins, they are making available environmental cleaning products that are safer for humans.

The Massachusetts Nurses Association suggests the following:

- Alternatives to Pesticides: A process known as Integrated Pest Management (IPM) begins with steps that should be taken to remove the attractions for pests and pathways for pests before chemicals are used. Such steps include: improved sanitation practices, (empty refuse containers more frequently), structural repairs (holes in the wall) to block the pathways for entrance and the use of non chemical pesticide devices, such as vacuuming crumbs and utilizing traps. Chemical pesticides have a place in this process but only as the last resort. Pesticides should only be applied in hospitals by those who have been specifically trained to do so. 

- Alternatives to Antimicrobial Cleaning Products: All antimicrobials have a measure of hazard associated with them. This is evident by reviewing the MSDS that accompany the products. By their nature disinfectants and sterilants are developed to destroy living organisms. While few safer alternatives exist, educating and training workers in the safest application and handling, utilizing proper dilution as well as appropriate personal protective equipment when working with these chemicals can reduce exposure and adverse health effects. In many cases, cleaning is needed but antimicrobial products are not and the total amount of antimicrobials used can be reduced.

- Alternatives to Environmental Cleaning Agents: Safer cleaning chemicals exist and are in use today in many environmentally conscious healthcare facilities. Microfiber mops and cleaning cloths are recognized by the Environmental Protection Agency (EPA) as a meaningful alternative to conventional floor cleaning with wet mops and buckets. This process eliminates the ergonomic hazard of lifting heavy water buckets and the EPA emphasizes that it dramatically reduces the amount of water and chemical products required for routine cleaning of hospital rooms.

In its position paper, the Massachusetts Nurses Association makes the following suggestions for best practices:

- Evaluate the environmental cleaning and antimicrobial products currently used by reviewing the adverse health and environmental effects noted on the MSDS. Begin to use alternative products with less potential for adverse health effects and environmental pollution. This is the most important strategy for protecting the health of healthcare workers and patients, as well as the environment

- Include a person with expertise in occupational health and safety on any committee or group that selects environmental cleaning products, antimicrobials and/or pesticides.

- Provide hazard communication training that meets the requirements of the OSHA Hazard Communication Standard 1910.1200 (h)(3) --   address the physical and health hazards of the chemicals in the work area and the measures for workers to use to protect themselves from these hazards;  the process to access MSDS should be posted and available at all times.

- Develop and communicate methods for reporting any symptoms that workers and patients experience when environmental cleaning products are in use. Medical evaluation and treatment should be provided as necessary.

References:

Arif AA, Delclos GL and Serra C. Occupational exposures and asthma among nursing professionals. Occup Environ Med. 2009;66:274-278.

Bello A, Quinn MM, Perry MJ and Milton DK. Quantitative assessment of airborne exposures generated during common cleaning tasks: a pilot study. Environ Health. 2010; 9:76.

Bello A, Quinn MM, Perry MJ, Milton DK. Characterization of occupational exposures to cleaning products used for common cleaning tasks--a pilot study of hospital cleaners. Environ Health. 2009 Mar 27;8:11.

Delclos GL, Gimeno D, Arif AA, Burau KD, Carson A, Lusk C, Stock T, Symanski E, Whitehead LW, Zock JP, Benavides FG, Antó JM. Occupational risk factors and asthma among healthcare professionals. Am J Respir Crit Care Med. 2007 Apr 1;175(7):667-75.

Donnay C, Denis MA, Magis R, Fevotte J, Massin N, Dumas O, Pin I, Choudat D, Kauffmann F, Le Moual N. Under-estimation of self-reported occupational exposure by questionnaire in hospital workers. Occup Environ Med. 2011 Aug;68(8):611-7.

Massachusetts Nurses Association. Exposure to Environmental Cleaning Chemicals in Healthcare Settings. October 2007. Accessed at: http://www.massnurses.org/nursing-resources/position-statements/env-cleaning-chem

Pechter E, Davis LK, Tumpowsky C, Flattery J, Harrison R, Reinisch F, Reilly MJ, Rosenman KD, Schill DP, Valiante D, et al. Work-relatedasthma among healthcare workers: surveillance data from California, Massachusetts, Michigan and New Jersey, 19931997. Am J Ind Med 2005;47:265275.

Additional resource:
Healthcare-related standards for respiratory protection, bloodborne pathogens and other topics can be found on OSHA's website: http://www.osha.gov/SLTC/healthcarefacilities/index.html