Back to Basics is a weekly feature that highlights important but possibly overlooked information that any EHS professional should know. This week, we examine how to prepare for a winter’s worth of respiratory illnesses in the workplace.
Could you find yourself looking at a “tripledemic” of COVID-19, influenza, and respiratory syncytial virus (RSV) in the workplace this winter? Are you ready?
The threat is real. Workplace respiratory illnesses spiked last year, according to figures recently released by the Bureau of Labor Statistics (BLS). After a decrease in 2021, the number of workplace respiratory illness cases were up 35.4% to 365,000 in 2022.
The rate of respiratory illnesses also rose in 2022 from 27.8 cases per 10,000 full-time equivalent (FTE) workers in 2021 to 35.8 cases. All illnesses rose 26.1% in 2022 to 460,700 cases, helping drive an overall increase in nonfatal workplace injuries and illnesses to 2.8 million.
How might this winter compare with the last one? The Centers for Disease Control and Prevention (CDC) released its respiratory disease season outlook in September, predicting this year will be similar to last year in terms of the total number of hospitalizations from COVID-19, influenza, and RSV. An October update—the CDC’s most recent—reported sustained increases in RSV activity in the Southern United States.
RSV is a common respiratory virus that usually causes mild, cold-like symptoms, according to the CDC. Older adults and infants are more likely to develop severe RSV that requires hospitalization. A vaccine is available for Americans aged 60 or older to protect them from severe RSV. An annual flu vaccine and an updated COVID-19 vaccine are available for all adults.
The CDC tracks cases of the flu in its weekly U.S. influenza surveillance report and all respiratory illnesses (“influenza-like illnesses”) in its weekly ILINet surveillance report, as well as in weekly Respiratory Virus Updates.
There currently is no federal infectious disease standard. However, the Occupational Safety and Health Administration (OSHA) has an infectious disease rulemaking for healthcare and other “high-risk” workplaces—one of the agency’s six economically significant rulemakings. The agency expects to issue a notice of proposed rulemaking in March 2024.
The infectious disease rulemaking would establish an occupational health standard for exposures to diseases that include chickenpox and shingles (varicella disease), measles, methicillin-resistant Staphylococcus aureus (MRSA), and tuberculosis (TB), as well as new and emerging infectious diseases like COVID-19, pandemic influenza, and severe acute respiratory syndrome (SARS).
Respiratory infections in the workplace, including COVID-19 and influenza, can have a major impact on businesses, according to the National Institute for Occupational Safety and Health (NIOSH). NIOSH has a collection of employer resources for preventing and responding to respiratory infections in the workplace. Prevention measures include cleaning and disinfection and ventilation and engineering controls like upper-room ultraviolet germicidal irradiation (UVGI).
Seasonal flu
Influenza viruses infect the nose, throat, and sometimes the lungs, causing mild to severe illness and sometimes death. Symptoms include fever, sore throat or cough, runny or stuffy nose, and muscle or body aches. Flu viruses in the United States typically circulate during the fall and winter. However, several other respiratory illnesses also circulate during “flu season,” according to the CDC.
The CDC retroactively characterizes the severity of a flu season based on the percentage of outpatient visits for influenza-like illnesses, percentage of hospitalizations, and percentage of deaths resulting from the flu. The 2019 to 2020 and 2022 to 2023 flu seasons were moderate-severity flu seasons.
The CDC’s 10 employer tips for preventing the spread of the flu at work are:
- Encourage employees to get a seasonal flu vaccine each fall.
- Consider hosting a flu vaccine clinic at the workplace.
- Encourage sick workers to stay at home without fear of any reprisals, developing or reviewing sick leave policies, if necessary.
- Advise employees to stay home if they’re sick until at least 24 hours after their fever (a temperature of 100 degrees Fahrenheit, or 37.8 degrees Celsius, or higher) is gone (without the use of fever-reducing medicines).
- Employees who appear to have flu symptoms upon arrival at work or who become sick during the workday should be separated from others and asked to go home.
- Develop flexible policies allowing employees to work from home, if feasible, and create leave policies to allow workers to stay home to care for sick family members or care for children if schools close.
- Employees who are well but who have a sick family member at home with the flu may come to work as usual, but those employees should monitor their health during the workday and notify their supervisor and go home if they become sick.
- Promote prevention by providing tissues, no-touch trash cans, hand soap, and/or hand sanitizer.
- Provide workers with up-to-date information on flu risk factors and prevention measures.
- Provide resources and education for employees who may be at high risk for serious flu complication, such as pregnant women or adults with a chronic medical condition like asthma, heart disease, or diabetes.
OSHA has offered similar guidance for non-healthcare employers during flu season:
- Promote vaccination.
- Encourage sick workers to stay home.
- Promote hand hygiene and cough etiquette.
- Keep the workplace clean.
OSHA also recommends addressing travel concerns, reconsidering business travel to areas with high rates of illness. Workers who become ill while traveling or on temporary assignment should notify their supervisors, according to CDC and OSHA recommendations.
OSHA recommends that workers get an annual flu vaccine to protect themselves, their families, and coworkers. A flu vaccine may make the flu less severe if a worker becomes infected. OSHA notes that flu season typically peaks between December and February and that healthcare workers face higher risk of exposure.
Good hand hygiene, cough and sneeze etiquette, and staying home when sick are critical components of prevention, according to OSHA.
The agency also encourages employers to improve workplace ventilation to minimize the inhalation of influenza, COVID-19, and other respiratory viruses that may be circulating.
COVID-19 guidelines
OSHA updated its “Guidance on Mitigating and Preventing the Spread of COVID-19 in the Workplace” on June 10, 2021. The June 2021 guidance recommended that employers:
- Offer employees time off to get vaccinated.
- Maintain physical distancing, and provide surgical masks or other face coverings.
- Implement the CDC’s building ventilation recommendations, consulting the American Society of Heating, Refrigerating, and Air-Conditioning Engineers’ (ASHRAE) guidelines.
- Perform routine workplace cleaning and disinfection.
- Suggest that unvaccinated customers, guests, and visitors wear non-respirator face coverings.
- Provide unvaccinated and otherwise at-risk workers with face coverings or surgical masks.
- Instruct infected employees and those who have had close contact with an infected individual to stay home.
In its guidelines, OSHA acknowledged that some workplaces may have mixed vaccination status among the workforce. The agency offered additional recommendations for higher-risk work settings that include close contact on production or assembly lines, in break rooms, in changing rooms/locker rooms, and in employer-provided housing and transportation.
The agency’s recommendations for higher-risk workplaces with mixed-vaccination-status workforces include:
- Staggering break times or providing temporary break areas and restrooms to prevent groups of unvaccinated or otherwise at-risk workers from congregating during breaks and ensuring unvaccinated or otherwise at-risk workers maintain at least 6 feet of distance from others at all times, including on breaks;
- Staggering workers’ arrival and departure times to prevent bunches of unvaccinated or otherwise at-risk workers in parking areas and locker rooms and near time clocks; and
- Providing visual cues, such as floor markings and signs, as reminders to maintain physical distancing.
Building ventilation, air filtration, portable air cleaners
Adequate ventilation and air filtration can lower indoor concentrations of infectious disease particles. Properly maintained heating, ventilation, and air conditioning (HVAC) systems can limit building occupants’ exposures to both infectious particles and wildfire smoke. Upgraded systems can improve both ventilation and air filtration.
An HVAC system’s filters are rated according to their Minimum Efficiency Reporting Value (MERV). HVAC system filters can range from MERV 2 to 16. Beyond MERV 16, high-efficiency particulate air (HEPA) filters can capture even more particles. Filters rated MERV 13 or higher can remove airborne particles introduced into a building’s systems from outdoor air—these include particles from desert dust storms, vehicle traffic, and wildfires. Highly rated filters can also capture infectious disease particles recirculated through a building’s air.
The ASHRAE’s Control of Infectious Aerosols standard (ASHRAE 241-2023) established recommendations for reducing infectious disease transmission risks by limiting exposure to infectious aerosols. Standard 241 is a consensus industry standard, which covers aspects of air system design, installation, operation, and maintenance.
The ASHRAE also maintains a collection of one-page guidance documents covering issues ranging from ventilation in industrial settings to in-room air cleaners and emerging environmental health issues.
Portable air cleaners or purifiers with high-efficiency particulate air (HEPA) filters can further reduce the concentration of infectious particles or particulate matter. The free-standing, plug-in portable air cleaners with HEPA filters capture infectious airborne particles in the rooms where they’re placed, including COVID-19, influenza, and RSV.
The CDC also has developed and recently updated “Ventilation in Buildings” guidelines. The CDC recommends that systems make five or more air changes per hour (ACH) of clean air to help reduce the concentration of infectious particles.
Steps recommended by the CDC to improve the air circulation in buildings include:
- Ensuring that, at a minimum, existing HVAC systems provide at least the minimum outdoor air ventilation suggested in the system’s ventilation design specifications.
- Consider increasing the introduction of outdoor air beyond the code-minimum requirements.
- Use fans to increase the effectiveness of open windows.
- Rebalance or adjust HVAC systems to increase total airflow to occupied spaces when possible.
The CDC also recommended upgrading HVAC system filters to MERV 13 or better. It also suggested using portable air cleaners or built-in HEPA fan/filtration systems or even UVGI (also known as GUV) as supplemental treatment. UVGI systems deactivate airborne viruses like SARS-CoV-2, the virus that causes COVID-19.
The Lancet COVID-19 Commission’s Task Force on Safe Work, Safe School, and Safe Travel produced a set of guidelines for building owners to reduce SARS-CoV-2 infection risks in schools and workplaces. Strategies recommended in the task force’s report “The First Four Healthy Building Strategies Every Building Should Pursue to Reduce Risk from COVID-19” included verifying that building systems are performing as designed, increasing outdoor air ventilation, upgrading air filtration, and deploying portable air cleaners where needed.
This year’s respiratory disease season may be similar to last year’s but be mindful that last year saw a spike in workplace respiratory illnesses, according to BLS data.