Middle Eastern Respiratory Syndrome Coronavirus (MERS-CoV) - Control and Prevention

Control and Prevention

Fig 1
Acceptable respiratory protection devices for protection against MERS-CoV include a properly fit-tested, NIOSH-approved filtering face piece respirator (N95 or higher level), half- or full-face air-purifying respirator (APR), or a powered air-purifying respirator (PAPR) equipped with high-efficiency particulate arrest (HEPA) filters. A N95 filtering face piece respirator is shown.

Photo Credit: CDC/Debora Cartagena

Preventive measures for protecting workers from exposure to MERS-CoV depend on the type of work performed and knowledge of exposure risk, including potential for MERS-CoV contamination of the work environment. Adaptation of infection control strategies based on a thorough hazard assessment is necessary for implementing infection prevention and control measures, including engineering and administrative controls, safe work practices, and personal protective equipment (PPE).

OSHA has developed the following interim guidance to help prevent worker exposure to MERS-CoV and persons with the disease.

General guidance for workers and employers
  1. Standard & Transmission-Based Precautions

    Employers should follow recognized good infection control practices (including standard precautions) to prevent or minimize transmission of infectious agents (i.e., MERS), and must comply with applicable requirements in the Bloodborne Pathogens (29 CFR 1910.134), Personal Protective Equipment (29 CFR 1910.132), general requirements) and the Respiratory Protection (29 CFR 1910.134) standards, among other OSHA requirements.

    Standard precautions include hand hygiene and use of PPE to avoid direct contact with laboratory specimens/samples (e.g., gloves, gown, mask, and eye protection). Standard precautions also include safe waste management as well as cleaning and disinfection of surfaces and equipment.

    Practice good hand hygiene protocols to avoid exposure to droplets, infected blood and body fluids, contaminated objects, or other contaminated environmental surfaces. Hand hygiene consists of washing with soap and water or using alcohol-based hand rubs containing at least 60% alcohol.1 Soap and water is best for hands that are visibly soiled. Perform hand hygiene before and after any contact with a patient with suspected or confirmed MERS, after any contact with potentially infectious material, and before putting on and upon removal of PPE, including gloves.

    Implement transmission-based precautions for contact- and airborne-transmissible diseases that are appropriate for each worker's tasks and potential exposure(s). OSHA's guidance incorporates these precautions. The Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) provide more information about infection control using standard and transmission-based precautions.

  2. Cleaning & Disinfection

    Protect workers from exposure when tasked with cleaning surfaces and equipment potentially contaminated with MERS-CoV. Employers are responsible for ensuring worker safety from harmful levels of chemicals used for cleaning and disinfection of areas potentially contaminated with MERS-CoV. For airborne exposures where OSHA has adopted a permissible exposure limit (PEL) (e.g. EtO), feasible engineering controls, such as ventilation, and administrative controls must be used to reduce the exposure to or below the PEL, and these controls are recommended for harmful exposures even when OSHA has not adopted a PEL.  In cases where engineering and administrative controls are not implemented or do not bring the exposure down to safe levels, PPE, such as chemical-resistant or -impermeable garments or a respirator with N95 particulate/chemical combination cartridge must be used.

    At this time, there is no EPA-approved list of disinfectants effective against MERS-CoV. EPA does not categorize disinfectants as hospital- or commercial-grade or keep a list of EPA-registered antimicrobial products registered for use in healthcare facilities.2 As a result, products effective at inactivating the virus must be determined based on data associated with inactivating similar or hardier (i.e., more difficult to inactivate) viruses. MERS-CoV is a coronavirus and highly susceptible to inactivation by many commonly used disinfectants. Currently, OSHA recommends following SARS disinfection practices (see section D-10 in the linked document) for environmental areas contaminated with MERS-CoV.3

    The CDC advises the use of EPA-registered chemical germicides that provide low or intermediate level disinfection for SARS during general use (surface and noncritical patient-care equipment) because these products inactivate related viruses with similar physical and biochemical properties. CDC's Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008 provides information on the effectiveness of germicides on coronaviruses.

  3. Personal Protective Equipment

    Select and provide workers with appropriate PPE to prevent exposure to MERS-CoV, blood or body fluids that may contain MERS-CoV, and other sources of infectious material.

    The precautions required determine the combination of PPE used. While the CDC currently recommends standard, contact and airborne precautions, the role of large-particle droplets in transmission of the virus has not been determined. Airborne precautions typically afford a higher level of protection than those for large-particle droplets; but, airborne precautions may not afford adequate protection of skin surfaces if MERS-CoV is transmissible via large-particle droplets. At this time, OSHA's PPE recommendations include additional protection of skin surfaces to ensure protection against large particle droplets.

    Acceptable respiratory protection devices for protection against MERS-CoV include a properly fit-tested, NIOSH-approved filtering face piece respirator (N95 or higher level), half- or full-face air-purifying respirator (APR), or a powered air-purifying respirator (PAPR) equipped with high-efficiency particulate arrest (HEPA) filters. Work tasks, including cleaning and decontamination activities, that involve an increase in moisture and spray may adversely affect disposable N95 respirators and certain other respirators. In such instances, a supplied-air respirator (SAR) may be an alternative to improve worker protection. Loose-fitting PAPRs and SARs may also improve worker comfort when wearing respirators for long periods.

    The OSHA Respiratory Protection standard (29 CFR 1910.134) requires medical clearance and fit testing to ensure appropriate respiratory selection and use. Fit testing is required for types of respirators requiring a tight seal around the face. Personnel who cannot wear fitted respirators because of facial hair or other fit limitations should wear loose-fitting PAPRs. OSHA's Respiratory Protection e-Tool provides detailed information on establishing a respiratory protection program.

    When the potential exists for exposure to blood or other potentially infectious materials, workers must use PPE required by the Bloodborne Pathogens standard (29 CFR 1910.1030). OSHA's Bloodborne Pathogens and Needlestick Prevention Safety and Health Topics page provides information on the standard.

  4. Infectious waste

    Worker protection from exposure to infectious agents, including MERS-CoV, is necessary when work tasks involve handling, treatment, transport, and disposal of medical, laboratory and other potentially contaminated waste. Mishandled contaminated waste may pose a risk to workers.

    Follow applicable waste disposal requirements for all infectious waste, including packaging requirements found in OSHA's Bloodborne Pathogens standard (29 CFR 1910.1030). Comply with the U.S. Department of Transportation's Hazardous Materials Regulations (49 CFR Part 172) if transporting waste off-site for treatment and disposal. State and local requirements may also apply.

  5. Reporting Illness

    Ensure that supervisors and all potentially exposed workers are aware of the symptoms of MERS.

    Workers potentially exposed to MERS-CoV who develop symptoms of MERS within the 14-day post-exposure period should seek medical evaluation.

    Report the possible case to the appropriate state health department and to the CDC.

    If the exposed worker was admitted as an in-patient to a hospital, report the case to OSHA.

    Workers may continue working during the 14-day post-exposure period if there are no symptoms of fever or respiratory illness.

While MERS-CoV appears to be limited in its ability for human-to-human transmission, OSHA's Protecting Workers during a Pandemic Fact Sheet may provide useful guidance about principles of worker protection in the event of a MERS outbreak with community transmission (i.e., outside of a hospital or other healthcare facility).

Worker Training

Train all workers with reasonably anticipated occupational exposure to MERS (as described in this document) about the sources of MERS-CoV exposure, the hazards associated with that exposure, and appropriate workplace protocols in place to prevent or reduce the likelihood of exposure. Training should include information about how to isolate individuals who may have MERS or other infectious diseases, and how to report possible cases. Training should also include safe handling and proper packaging, treatment, transport and disposal of waste contaminated with MERS-CoV.

Workers required to use PPE must be trained. This training includes when to use PPE; what PPE is necessary; how to properly don (put on), use, doff (take off) PPE; how to properly dispose of or disinfect, inspect for damage and maintain PPE; and the limitations of PPE. Applicable standards include the PPE (29 CFR 1910.132), Eye and Face Protection (29 CFR 1910.133), Hand Protection (29 CFR 1910.138), and Respiratory Protection (29 CFR 1910.134) standards. The OSHA web site offers a variety of training videos on respiratory protection.

When the potential exists for exposure to blood or other potentially infectious materials, workers must receive training required by the Bloodborne Pathogens (BBP) standard (29 CFR 1910.1030), including information about how to recognize tasks that may involve exposure and the methods to reduce exposure, including engineering controls, work practices, and PPE. Further information on OSHA's BBP training regulations and policies is available for employers and workers on the OSHA Bloodborne Pathogens and Needlestick Prevention Safety and Health Topics page.

OSHA's Training and Reference Materials Library contains training and reference materials developed by the OSHA Directorate of Training and Education (DTE) as well as links to other related sites. The materials listed for Bloodborne Pathogens, PPE, Respiratory Protection and SARS may provide additional material for employers to use in preparing training for their workers.

OSHA's Personal Protective Equipment Safety and Health Topics page also provides information on training in the use of PPE.

If You Think You Have Been Exposed

Any worker who thinks he or she may have been exposed to MERS-CoV, including through travel, assisting an ill traveler or other person, handling a contaminated object, or cleaning a contaminated environment (such as an aircraft) should take the following precautions:

  • Notify your employer immediately.
  • Monitor your health for 14 days. Watch for fever (temperature of (≥ 38°C/100.4°F or higher), cough, shortness of breath and other symptoms consistent with MERS.
  • Seek medical attention if you develop any of these symptoms.
  • Before visiting a healthcare provider, alert the clinic or emergency room in advance about your possible exposure to MERS-CoV so that staff can implement precautions to prevent spreading it to others.
  • When traveling to a healthcare provider, limit contact with other people.
  • Avoid all other travel.

If you are abroad, contact your employer for help with finding a healthcare provider. The U.S. embassy or consulate in the country where you are visiting can also provide names and addresses of local physicians.

Physicians, employers, and/or workers may contact their state or local health departments to notify them of any symptomatic workers or suspected exposure incidents.

In addition to the general guidance specified above, detailed recommendations follow for protecting workers at risk for potential exposure to MERS-CoV. Organized by job type, the guidance provides prevention and control strategies specific for each worker.

Information for workers (by job type):

Healthcare Workers

In addition to the general guidance, applicable to all workers, provided at the beginning of this tab, OSHA recommends the following controls for Healthcare Workers.

Employers of healthcare workers are responsible for following applicable OSHA requirements, including OSHA's Bloodborne Pathogens (29 CFR 1910.1030), Personal Protective Equipment (29 CFR 1910.132), and Respiratory Protection (29 CFR 1910.134) standards. For additional information on OSHA requirements, visit the Standards section.

  1. Engineering Controls

    Engineering controls are the first line of defense in healthcare facilities to shield healthcare workers, patients and visitors from individuals with suspected/confirmed MERS. This includes physical barriers or partitions in triage areas to guide patients, curtains separating patients in semi-private areas, and airborne infection isolation rooms (AIIRs) with proper ventilation.

    Place persons under investigation (PUIs) for MERS in an AIIR if available at the healthcare facility. AIIRs are single patient rooms with negative pressure that provide a minimum of 6 air exchanges (existing structures) or 12 air exchanges (new construction or renovation) per hour. Ensure that the room air exhausts directly to the outside, or passes through a HEPA filter, if recirculated.

    If an AIIR is not available, isolate the patient in an examination room with the room exhaust filtered through a HEPA filter, if possible. Keep the door closed. In this situation, also place a surgical mask on the patient, if tolerated, to reduce the possibility of transmission through respiratory secretions. Note: A surgical mask on a patient should not be confused with PPE for a worker; the mask acts to contain potentially infectious respiratory secretions at the source (i.e., the patient).

    Isolation tents or other portable containment structures may serve as alternative patient-placement facilities when AIIRs are not available and/or examination room space is limited. Ensure that the room air exhausts directly to the outside, or passes through a HEPA filter, if recirculated.

    The CDC/HICPAC Guidelines for Environmental Infection Control in Healthcare Facilities contains additional information on negative-pressure room control for airborne infection isolation.

  2. Administrative Controls

    Isolate suspected and confirmed cases of MERS-CoV to prevent transmission of the disease to other individuals. If possible, isolating suspected cases separately from confirmed cases may also help prevent transmission. CDC has developed interim guidance for healthcare providers who are coordinating the home care and isolation or quarantine of people confirmed or suspected to have MERS.

    Restrict the number of personnel entering the room of a patient with suspected/confirmed MERS. This may involve training healthcare workers in appropriate use of PPE so they can perform tasks such as housekeeping and meal service to reduce the need for environmental and food service workers to enter areas where suspected or confirmed MERS patients are isolated.

    Minimize aerosol-generating procedures (AGPs), performing only those that are necessary for clinical diagnosis and care of a patient.

    Minimize the number of staff present when performing AGPs.

  3. Work Practices

    The CDC recommendations include following standard, contact, and airborne precautions, as appropriate, based on work tasks and potential exposures.

    Perform as many tasks as possible in areas away from a patient with suspected/confirmed MERS (e.g., do not remain in an isolation area to perform charting; use closed-circuit television systems to communicate with patients in an isolation area when a worker does not need to be physically present).

    Work from clean to dirty (i.e., touching clean body sites or surfaces before touching dirty or heavily contaminated areas) and limit opportunities for touch contamination (e.g., adjusting glasses, rubbing nose, or touching face with gloves that have been in contact with suspected/confirmed MERS patients or contaminated/potentially contaminated MERS-CoV contaminated surfaces). Also, prevent touch contamination by avoiding unnecessary touching of environmental surfaces (such as light switches and door handles) with contaminated gloves.

    Ensure that there are systems in place to differentiate clean areas (e.g., where PPE is put on) from potentially contaminated areas (e.g., where PPE is removed); to handle waste and other potentially infectious materials; and to clean, disinfect, and maintain reusable equipment and PPE.

    Train and retrain workers on how to follow the established protocols.

    See the general guidance for cleaning and disinfection above for recommendations on disinfection of environmental surfaces and noncritical patient-care equipment potentially contaminated with MERS-CoV.

    Follow standard practices for high-level disinfection and sterilization of semi-critical and critical medical devices contaminated with MERS as described in the CDC Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008.

  4. Personal Protective Equipment

    Healthcare workers must use proper PPE when exposed to a patient with confirmed/suspected MERS or other sources of MERS-CoV (See OSHA's PPE standards, 29 CFR 1910 Subpart I). This includes:

    • Clean, non-sterile gloves, unless otherwise clinically indicated (nitrile).
    • Fluid-resistant shoe and boot covers (high enough to cover lower leg).
    • Fluid-resistant gowns to protect the skin and/or clothing (should fully cover the torso, and sleeves should fit snuggly at the wrist).
    • Head and neck cover (e.g., surgical hood) to minimize skin contact.
    • Disposable goggles or face shield to protect the eyes and mucous membranes.
    • Respirator at least as protective as a disposable N95 filtering face piece to protect the mouth and nose as well as respiratory tract from airborne transmission of the virus.

    The suggested sequence to follow for donning (putting on) PPE for respiratory pathogens is: first, boot covers; then, gown; followed by respirator (properly adjusted to fit); then, surgical hood; face shield; and gloves last.

    Healthcare workers should pay close attention when removing PPE to prevent contamination of clothing and skin during the process. The recommended sequence to follow for doffing (taking off) PPE is: first, gloves; then, boot covers; face shield; then, gown; followed by respirator and surgical hood. Workers should not remove respirators until after leaving a patient's room and closing the door.

    After removing PPE, always wash hands with soap and water, if available. Ensure that hand hygiene facilities (e.g., sink or alcohol-based hand rub) are readily available at the point of use (e.g., at or adjacent to the PPE doffing area).

  5. Further Information

    CDC provides detailed information about infection control and prevention for MERS-CoV in healthcare settings: Interim Infection Prevention and Control Recommendations for Hospitalized Patients with Middle East Respiratory Syndrome Coronavirus (MERS-CoV); Guidelines for Environmental Infection Control in Healthcare Facilities; and Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings.

    CDC has also developed the Healthcare Providers Preparedness Checklist and the Healthcare Facility Preparedness Checklist to assist the healthcare industry in preparing for handling patients with suspected MERS. These checklists summarize key preventive steps that hospitals and healthcare providers can take to plan for MERS-CoV infection control.

    The CDC provides up-to-date, practical, and effective information and resources on infection control on its Healthcare-associated Infections (HAIs) web page. Some of this information may be applicable to control and prevention of MERS-CoV infections.

    To meet the urgent need for up-to-date information and evidence-based recommendations for the safe care of patients with suspected/confirmed MERS-CoV infection, WHO has also published the interim guidance, Infection prevention and control during health care for probable or confirmed cases of Middle East respiratory syndrome coronavirus (MERS-CoV) infection.

Medical Transport Workers

Workers involved in pre-hospital or inter-facility transport of patient(s) with suspected/confirmed MERS must be protected from exposure to MERS-CoV. These workers, including emergency medical service (EMS) personnel and other emergency responders, also may have potential exposure to the disease through patient contact or MERS-CoV-contaminated environments if a MERS outbreak affects the U.S.

Employers of medical transport workers are responsible for following applicable OSHA requirements, including OSHA's Bloodborne Pathogens (29 CFR 1910.1030), Personal Protective Equipment (29 CFR 1910.132), and Respiratory Protection (29 CFR 1910.134) standards. For additional information on OSHA requirements, visit the Standards section of this web page.

In addition to the general guidance, applicable to all workers, which is provided at the beginning of this tab, OSHA also recommends the following controls for medical transport workers.

Guidelines Applicable to Both Air Medical Transport and EMS Workers

  1. Engineering controls

    Place a surgical mask on the patient, if tolerated, to reduce the possibility of transmission through respiratory secretions. Note: A surgical mask on a patient should not be confused with PPE for a worker; the mask acts to contain potentially infectious respiratory secretions at the source (i.e., the patient).

  2. Administrative Controls

    Sharing of information during transfer of patient care from the medical transport team to the healthcare provider is critical for effective infection prevention and control. When transporting a patient with suspected/confirmed MERS, transport workers should convey this information to the receiving facility in advance, if possible, or immediately upon arrival.

    Standardizing infection control practices (including selection and use of PPE) between hospital facilities, transport organizations (e.g., EMS), air ambulance service providers, and others may also improve consistent implementation of controls across workplaces involved in patient transport and care.

  3. Work Practices

    The CDC recommendations include following standard, contact, and airborne precautions, as appropriate, based on work tasks and potential exposures.

    Minimize the amount of time workers spend enclosed in an ambulance, aircraft, or other vehicle with a patient with suspected/confirmed MERS. Perform as much work as possible outside of areas where close contact with sources of MERS-CoV is likely. For instance, complete administrative tasks that do not require interaction with the patient, such as charting or pre/post-transport radio and phone calls, outside of the vehicle.

    Work with state and local law enforcement and other public safety organizations to ensure that a safe, unimpeded, direct route is available when transporting a patient with suspected/confirmed MERS between locations or facilities.

    Decontaminate vehicles as soon as possible after transporting a patient with suspected/confirmed MERS. See the general guidance on cleaning and disinfection provided above.

    Do not use compressed air or water sprays for cleaning aircraft or ambulances, as these techniques may re-aerosolize infectious material.

  4. Personal Protective Equipment

    Employers must ensure workers use proper PPE when exposed to a patient with confirmed/suspected MERS or other sources of MERS-CoV (See OSHA's PPE standards, 29 CFR 1910 Subpart I). Follow proper protocol for donning and removal of PPE, described in the Healthcare Workers section above.

    Remove and discard gloves and gowns in accordance with procedures for handling infectious waste, described in the general guidance section after patient care is completed or when items are soiled or damaged.

Air Medical Transport Workers

The CDC has published recommendations to protect workers who may be required to transport patients with MERS by air in its Guidance on Air Medical Transport for Middle East Respiratory Syndrome (MERS) Patients. It provides detailed controls (e.g., engineering and administrative, work practices and PPE) to assist air medical transport service providers in using specialized and/or specially equipped aircraft to transport MERS patients while ensuring the safety of patients and transport personnel.

The NIOSH web page, Air Crew Safety and Health – Communicable Diseases, provides more information and resources about protecting cabin crew and other passengers from travelers with infectious disease.

The CDC web page, Quarantine and Isolation -- Airline Guidance for Managing Ill Passengers/Crew, may also provide helpful guidance for airlines on general infection control.

Also refer to the Guidelines Applicable to Both Air Medical Transport and EMS Workers.

Note on air medical transport workers: The health and safety of air medical transport workers may be under the jurisdiction of the Federal Aviation Administration (FAA), and not OSHA, depending on the activities in which these workers are engaged and hazards to which these workers are exposed. For more information, see discussion of the MOU between FAA and OSHA, in the OSHA Standards section.

EMS Workers

  1. Engineering Controls

    Vehicles that have separate driver and patient compartments and can provide separate ventilation to these areas are preferred for transport of suspected/confirmed MERS patients.

    Close the door/window between the driver/patient compartments before bringing a patient with suspected/confirmed MERS on board.

    If a vehicle without separate compartments and ventilation is used, the outside air vents in the driver compartment should be open, and the rear, exhaust ventilation fans turned on at the highest setting to provide a gradient of negative pressure in the patient care compartment.

  2. Administrative Controls

    Refer to the Guidelines Applicable to Both Medical Air Transport and EMS Workers.

  3. Work Practices

    The CDC recommendations include following standard, contact, and airborne precautions, as appropriate, based on work tasks and potential exposures.

    Clean non-patient-care areas of the vehicle according to standard employer protocols.

    Clean and disinfect patient-care compartments (including stretchers, railings, medical equipment, control panels, and adjacent flooring, walls and work surfaces contaminated or potentially contaminated with MERS-CoV) in accordance with recommendations for disinfection specified in the general guidance above.

  4. Personal Protective Equipment

    Use the same PPE listed for healthcare workers throughout transport of a patient with suspected/confirmed MERS, except workers need not use fluid-resistant shoe and boot covers and head and neck covers.

    If the driver compartment cannot be closed off from the patient-care compartment, drivers also need to wear N95 (or higher) respirators. Employers should monitor the driver's use of respirators to ensure that the respirator does not restrict the worker's ability to operate a vehicle safely.

    If the driver assists with direct patient care, including moving patients on stretchers, the driver should wear all other recommended PPE for EMS Workers.

    Personnel who clean the patient-care compartment should wear nonsterile gloves, disposable gowns and eye protection.

  5. Further Information

    OSHA's Emergency Preparedness and Response page provides more information for emergency response and recovery workers and their employers.

    NIOSH provides emergency response resources to assist emergency responders in preparing for critical events, including potential exposure to biological agents and infectious diseases, such as MERS.

Laboratory Workers

Laboratory workers who handle clinical specimens from patients with suspected/confirmed MERS or samples of MERS-CoV as part of research and development work must be protected from exposure.

Follow recognized good biosafety practices to prevent or minimize transmission of infectious agents (i.e., MERS). Laboratories should already be using standard precautions as specified in the general guidance above, and should be following standard laboratory practices. These practices should continue when working with MERS-CoV samples/specimens. This includes clinical and microbiological laboratories performing routine diagnostic, analytical, or other research-related tests on serum, blood, urine, sputum (respiratory), and stool specimens.

Employers of laboratory workers are responsible for following applicable OSHA requirements, including OSHA's Bloodborne Pathogens (29 CFR 1910.1030), Personal Protective Equipment (29 CFR 1910.132), and Respiratory Protection (29 CFR 1910.134) standards. In addition to OSHA requirements that are broadly applicable to occupational exposure to MERS-CoV and related hazards, such as chemicals used for cleaning and disinfection, laboratory employers must also follow specific requirements that apply to labs. For additional information on OSHA requirements, visit the Standards section of this web page.

Laboratory employers should routinely review standard laboratory practices and safety and health procedures with lab workers; train and test the competency of workers in appropriate implementation of these procedures and practices; and ensure consistent adherence to them.

Laboratory personnel working with samples suspected/confirmed to contain MERS-CoV should immediately report to their supervisor any incidents or accidents involving potential or actual exposure to MERS-CoV, as well as development of symptoms consistent with MERS.

Employers should implement appropriate protocols for handling, storing, and shipping specimens and ensure adherence by all laboratory workers. Packaging, shipping, and transport of specimens suspected or known to be contaminated with MERS-CoV may be regulated by the Bloodborne Pathogens standard (29 CFR 1910.1030), the U.S. Department of Transportation's Hazardous Materials Regulations, CDC and USDA permitting requirements for biological select agents and toxins, and state and local requirements.

Laboratories should ensure that their facilities and precautions meet the appropriate Biosafety Level (BSL) for the type of work conducted (including the specific biological agents – in this case, MERS-CoV) in the lab. The CDC's Biosafety in Microbiological and Biomedical Laboratories (BMBL), 5th Edition provides detailed guidance on BSLs in Section IV - Laboratory Biosafety Level Criteria. Increasing BSL levels involves more worker training, higher levels of containment of samples and other sources of pathogens, specially-designed air handling systems, additional worker PPE, and other stricter controls. For example, at BSL-2, access to laboratories and other controlled work areas is limited when work is occurring and certain procedures are conducted in biosafety cabinets or other containment equipment. At BSL-3, in addition to controlling access to laboratories and work areas, all work involving infectious materials is conducted in biosafety cabinets or other containment equipment.

The following procedures may be conducted at BSL-24:

  • pathologic examination and processing of formalin-fixed or otherwise inactivated tissues
  • molecular analysis of extracted nucleic acid preparations
  • electron microscopic studies with glutaraldehyde-fixed grids
  • routine examination of bacterial and fungal cultures
  • routine staining and microscopic analysis of fixed smears
  • final packaging of specimens for transport to diagnostic laboratories for additional testing (specimens should already be in a sealed, decontaminated primary container)

Perform activities involving manipulation of untreated specimens in BSL-2 facilities following BSL-3 practices.

In addition to the general guidance, applicable to all workers provided at the beginning of this tab, OSHA recommends the following controls for laboratory workers:

  1. Engineering Controls

    To maximize worker protection, perform as much work as possible in a properly maintained and certified biosafety cabinet (BSC). Class I BSCs use negative pressure and high-efficiency particulate arrest (HEPA) filters to contain agents and protect workers and the environment. Class II and III BSCs provide higher levels of containment and filtration that also protect samples or other products in the BSC from contamination.

    Ensure that all procedures involving manipulation of untreated specimens or that have the potential to generate aerosols (e.g., vortexing or sonication of specimens in an open tube, etc.) are conducted in a BSC while following BSL-3 practices.4 Use appropriate physical containment devices (such as sealed centrifuge rotors or safety carriers with gaskets) for centrifugation.

    The OSHA Fact Sheet, Laboratory Safety Biosafety Cabinets (BSC), provides guidance on training and effective use of BSCs.

  2. Administrative Controls

    Train all laboratory personnel on any additional procedures developed by the employer for safely handling specimens from patients with suspected/confirmed MERS. This includes training on the communication procedures in effect between the clinical and laboratory staff to ensure timely notification and proper labeling of suspected/confirmed MERS-CoV contaminated specimens.

    Use administrative controls that maximize the protectiveness of engineering controls, including BSCs. For example, maintain chemical reagents involved in research or diagnostic work below their lower explosive limits, especially in BSCs.

  3. Work Practices

    Use work practices that maximize the protectiveness of engineering controls, including BSCs. For example, if a BSC does not operate continuously, turn it on and allow it to operate for several minutes before use to allow airflow to stabilize. Similarly, wait a few moments before beginning work after inserting arms into a BSC to allow the protective air curtain around the arms to stabilize.

    Use technical procedures that minimize the formation of aerosols and droplets. As a corollary, avoid procedures that generate aerosols and droplets (e.g., pipetting, vortexing tubes) and perform any necessary aerosol-generating procedures in containment (e.g., inside a BSC) and/or while using appropriate precautions, including worker PPE.

    See general guidance for recommendations on disinfection of environmental surfaces and noncritical patient-care equipment potentially contaminated with MERS-CoV.

    Use an autoclave to inactivate infectious material in all waste prior to disposal. Adhere to applicable federal, state and local regulations when disposing of laboratory waste.

  4. Personal Protective Equipment

    All laboratory workers working with MERS-CoV must wear appropriate PPE (29 CFR 1910.132). The BSL provides guidance for selecting appropriate PPE for the tasks that are conducted. This may include disposable nonsterile gloves, laboratory coat/gown, and eye protection when handling specimens at BSL-2. The lab coat or solid-front gown should have a knit or grip cuff. Use double gloves that extend over the sleeve of the lab coat or gown.

    At BSL-3, including when conducting procedures that may generate aerosols, use a NIOSH-approved N95 (or higher) respirator as part of a respiratory protection program that meets the requirements of the Respiratory Protection standard (29 CFR 1910.134).

    When using a BSC, remove the outer pair of gloves before exiting the BSC, and don a new pair each time reentering the BSC.

  5. Further Information

    The CDC guidance Interim Laboratory Biosafety Guidelines for Handling and Processing Specimens Associated with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) - Version 2 provides more specific guidelines on the appropriate protection needed for activities involving MERS-CoV as well as packing, shipping and transport of MERS-CoV specimens.

    Biosafety in Microbiological and Biomedical Laboratories (BMBL), 5th Edition provides guidance on protecting workers in laboratory environments. The following sections may be particularly relevant to employers and workers whose workplaces may contain MERS-CoV:

    Section VII - Occupational Health and Immunoprophylaxis

    Section VIII - E – Viral Agents Agent Summary

    The WHO resource, Laboratory Biosafety Manual - Third Edition, contains additional practical guidance on biosafety techniques for use in laboratories at all levels.

Airline Workers

Exposure to communicable diseases (such as MERS) that are not common in the U.S. is possible during flights with international travelers and stops in other countries. At this time, airline worker exposure to MERS-CoV is not likely, as MERS has typically been associated with transmission in hospitals and other healthcare settings. However, airline personnel may be at some risk for exposure to infectious diseases, including MERS, during air travel.

The general guidance outlined at the beginning of this tab provides generic recommendations and OSHA requirements for protections and controls applicable to all workers with potential risk of exposure to MERs-CoV. In general, the safety and health of aircraft cabin crewmembers and flightcrew members are under the jurisdiction of the Federal Aviation Administration (FAA) and not covered by OSHA standards while they are on aircraft in operation. However, under a policy statement issued by FAA and a Memorandum of Understanding (MOU) between the FAA and OSHA, Occupational Safety and Health Standards for Aircraft Cabin Crewmembers, aircraft cabin crewmembers are covered by OSHA's Bloodborne Pathogens, Occupational Noise, and Hazard Communication standards while they are on aircraft in operation (which occurs from the time the aircraft is first boarded by a crewmember, preparatory to a flight, to the time the last crewmember leaves the aircraft after completion of that flight, including stops on the ground during which at least one crewmember remains on the aircraft, even if the engines are shut down). These include flight attendants, workers assigned to clean and restock the cabin, and other workers assigned to perform duty in an aircraft cabin when the aircraft is in operation. For more information, see the discussion of the MOU between FAA and OSHA, earlier in this document.

In addition to the general guidance, OSHA recommends the following controls for airline workers.

  1. Engineering Controls

    Place a surgical mask on the ill travelers or crew members, if tolerated, to reduce the possibility of transmission through respiratory secretions. Note: A surgical mask on an ill individual should not be confused with PPE for a worker; the mask acts to contain potentially infectious respiratory secretions at the source (i.e., the ill individual).

    Minimize ventilation downtime on airplanes parked at the gate. When the airplane is operating, the ventilation system brings in fresh air, filters the air, and circulates the air within the cabin. All these actions reduce the potential transmission of airborne infectious disease.

  2. Administrative Controls

    Ensure that Universal Precautions Kits (UPKs) are stocked on board commercial airplanes and available to workers to ensure a timely response to a patient with a suspected infectious disease. The number of UPKs required depends on the type of aircraft and the number of flight attendants on board as specified in the Standards and Recommended Practices of the International Civil Aviation Organization. Typically, UPKs include:

    • instructions for cleaning up vomit and other body fluids
    • biohazard bags
    • a large, absorbent towel or other absorbent material
    • dry powder that can convert a small liquid spill into a granulated gel
    • disposable scoops with scraper
    • germicidal disinfectant for surface cleaning
    • skin wipes
    • face/eye protection (separate or combined)
    • nonsterile gloves (disposable)
    • an impermeable, full-length, long-sleeved gown that fastens at the back5

    Airline flight crews should notify ground and cleaning crews in the event that a passenger with suspected MERS has disembarked a commercial aircraft. This will allow crews who clean and disinfect the aircraft to protect themselves effectively.

    The CDC has issued recommendations for aircraft crewmembers to follow for reporting to CDC ill travelers (with symptoms) traveling from countries in and near the Arabian Peninsula and South Korea: Middle East Respiratory Syndrome (MERS) Interim Guidance for Airline Crew: Report Ill Travelers on Flights Arriving to the United States.

    Visit the CDC web page, Guidance for Airlines on Reporting Onboard Deaths or Illnesses to CDC, for other information on reporting requirements.

    OSHA also advises following guidance on CDC's Infection Control Guidelines for Cabin Crew Members on Commercial Aircraft page, which contains information on clean-up and post-flight measures.

    For cleaning crews, the International Air Transport Association (IATA) provides Air Transport and Communicable Diseases for protecting workers cleaning and disinfecting the aircraft after patient transport.

  3. Work Practices

    The CDC recommendations include following standard, contact, and airborne precautions, as appropriate, based on work tasks and potential exposures.

    Do not use compressed air or water sprays to clean potentially contaminated surfaces of aircraft (e.g., surfaces with which a potentially infectious passenger may have had contact), as these techniques may re-aerosolize infectious material.

    When cleaning a commercial passenger aircraft after a flight with a suspected MERS patient, sanitize passenger lavatory surfaces and frequently touched surfaces in the passenger cabin where the traveler sat in accord with the General Guidance, Cleaning and Disinfection, under the Control and Prevention section. Include the armrests, seat backs, tray tables, light and air controls in rows immediately around the row the person was located. Also, disinfect adjacent walls and windows.

    The CDC has developed Infection Control Guidelines for Cabin Crewmembers on Commercial Aircraft to help cabin crewmembers protect themselves, passengers, and other crewmembers from an ill traveler with a possible contagious infection, like MERS. These guidelines include sanitation procedures, procedures for management of an ill traveler, clean-up protocols, and post-flight procedures.

  4. Personal Protective Equipment

    Airline crewmembers generally do not need to use PPE. However, in some situations, such as when interacting with an ill traveler or performing cleaning tasks, airline crewmembers may wish to use clean, nonsterile gloves and other items from the UPK. Any PPE should be used in accord with CDC's Infection Control Guidelines for Cabin Crew Members on Commercial Aircraft.

    Provide nonsterile gloves to airport ground personnel, including airline cleaning crews, as well as workers conducting passenger screening tasks (e.g., border and immigration inspections, security screening).

    Remove, discard and replace soiled or damaged gloves while performing cleaning and disinfection of the aircraft.

Mortuary Workers

Mortuary and death care workers who have contact with human remains known or suspected to be contaminated with MERS-CoV must be protected from exposure to infected blood and body fluids, contaminated objects, or other contaminated environmental surfaces.

Employers of mortuary and death care workers are responsible for following applicable OSHA requirements, including OSHA's Bloodborne Pathogens (29 CFR 1910.1030), Personal Protective Equipment (29 CFR 1910.132), and Respiratory Protection (29 CFR 1910.134) standards. For additional information on OSHA requirements, visit the Standards section.

Prompt cremation of the remains of individuals who have died of MERS can help prevent worker exposure to MERS-CoV.

Follow recognized good biosafety practices to prevent or minimize transmission of infectious agents (i.e., MERS). To protect workers from MERS-CoV exposure, OSHA recommends suspension of post mortem or autopsy procedures on patients with suspected/confirmed MERS. This recommendation considers the potential for very high viral load (i.e., the number of viral particles in the body) at death and sources of exposure to workers performing autopsy procedures. If deemed necessary and appropriate, OSHA recommends strict adherence to basic safety procedures used for any autopsy on human remains, the general guidance applicable to all workers provided at the beginning of this tab, and the controls described below.

  1. Engineering controls

    Perform autopsies on human remains infected or potentially infected with MERS-CoV in autopsy suites that have adequate air-handling systems. This includes systems that maintain negative pressure relative to adjacent areas and that provide a minimum of 6 air exchanges (existing structures) or 12 air exchanges (new construction or renovation) per hour. Ensure that room air exhausts directly to the outside, or passes through a HEPA filter, if recirculated. Direct air (from exhaust systems around the autopsy table) downward and away from workers performing autopsy procedures. CDC's Guidelines for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings provides guidelines for AIIR use and recommendations for air exchange rates, which are similar to what should be followed in autopsy suites. Section VIII - Infection Control for Laboratory and Pathology Procedures of CDC's Infection Control in Healthcare, Home, and Community Settings for SARS also provides guidance applicable to pathology work, including autopsies, for coronaviruses.

    Use a BSC for the handling and examination of smaller specimens and other containment equipment whenever possible.

    Equipment, such as saws, should be equipped with vacuum shrouds to capture aerosols.

  2. Administrative Controls

    Restrict the number of personnel entering the autopsy suite. This may involve training mortuary workers, such as medical examiners or autopsy technicians, to perform environmental services tasks (e.g., cleaning and decontamination) in lieu of additional workers entering such areas.

    Minimize aerosol-generating procedures (AGPs), performing only those that are necessary to perform the autopsy or prepare remains for cremation.

    Minimize the number of staff present when performing AGPs. Exclude those who may be necessary for other procedures but not specifically the AGP.

  3. Work Practices

    Follow standard safety procedures for preventing injuries to/through the skin during autopsy. Use caution when handling needles or other sharps, and dispose of these items in puncture-proof containers.

  4. Personal Protective Equipment

    All mortuary workers and death care workers who have contact with human remains known or suspected to be contaminated with MERS-CoV must wear appropriate PPE (see OSHA's PPE standards, 29 CFR 1910 Subpart I). This includes:

    1. Workers Performing Autopsies:

      Wear typical autopsy PPE, including a scrub suit worn under an impermeable gown or apron, goggles or face shield, double surgical gloves interposed with a layer of cut-proof synthetic mesh gloves, and shoe covers.

      Because of the sustained likelihood of aerosol generation during various steps of autopsy procedures, use respiratory protection as specified in the general guidance section applicable to all workers.

      Remove PPE before leaving the autopsy suite and follow appropriate disposal requirements. After removing PPE, always perform good hand hygiene practices as described in the general guidance section.

    2. For Other Workers Handling Human Remains:

      Wear latex or nitrile, nonsterile gloves when handling potentially infectious materials.

      If there is a risk of cuts, puncture wounds or other injuries that break the skin, wear heavy-duty gloves over the latex/nitrile gloves.

      Wear a clean, long-sleeved fluid-resistant or impermeable gown to protect the clothing.

      Use a plastic face shield or a surgical mask and goggles to protect the face, eyes, nose and mouth from potentially infectious body fluids. If there is a risk of aerosol generation while handling human remains, use respiratory protection as specified in the general guidance section applicable to all workers.

      See the OSHA Fact Sheet, Health and Safety Recommendations for Workers Who Handle Human Remains, for more guidelines to ensure worker safety when handling human remains.

Updated Information

CDC's Health Alert Network (HAN) is its primary method for sharing cleared information about urgent public health incidents with public information officers; federal, state, territorial, and local public health practitioners; clinicians; and public health laboratories. Employers can sign up for HAN e-mails to obtain the latest information available on MERS and other infectious diseases.

The WHO web site is another resource to consult for updates on existing MERS outbreaks as well as for general information, technical guidance, and updates on MERS and MERS-CoV.


1 Airport Cooperative Research Program, "Infectious Disease Mitigation in Airports and on Aircraft" , ACRP Report, 91, Transportation Research Board of the National Academies (2013).

2 U.S. Environmental Protection Agency, "Pesticide Labeling Questions and Answers – Antimicrobial Claims."

3 Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, "Supplement I: Infection Control in Healthcare, Home, and Community Settings."

4 U.S. Department of Health and Human Services, "Biosafety in Microbiological and Biomedical Laboratories, 5th ed", p. 225.

5 Code of Federal Regulations, Title 49, "Transportation," U.S. Department of Transportation (49 CFR 172).