Occupant Safety and Health  

the WBDG Secure/Safe Committee


Modern buildings are generally considered safe and healthy working environments. However, the potential for indoor air quality problems, occupational illnesses and injuries, exposure to hazardous materials, and accidental falls beckons architects, engineers, and facility managers to design and maintain buildings and processes that ensure occupant safety and health. Notably, building designs must focus on eliminating or preventing hazards to personnel, rather than relying on personal protective equipment and administrative or process procedures to prevent mishaps.

Protecting the health, safety, and welfare (HSW) of building occupants has expanded beyond disease prevention and nuisance control to include mental as well as physical health (see Productive) and protecting the ecological health of a place (see Sustainable) through the creation of spaces that enable delight and the realization of human potential.

Using computational fluid dynamics to study threats to occupants from indoor air contamination

Threats to occupants from indoor air contamination can be studied using Computational Fluid Dynamics.

Therefore, the design team should apply an integrated approach, including work process analysis and hazard recognition to develop solutions that provide healthy built environments, having no undue physical stressors, as well as meeting other project requirements. In addition, consideration of HSW issues should be an integral part of all phases of a building's life cycle: planning, design, construction, operations and maintenance, renovation, and final disposal.

  • Provide designs that eliminate or reduce hazards in the work place to prevent mishaps and reduce reliance on personal protective equipment.
  • Prevent occupational injuries and illnesses.
  • Prevent falls from heights.
  • Prevent slips, trips, and falls.
  • Ensure electrical safety from turn-over through Operations and Maintenance. Modifications must be in conformance with life safety codes and standards and be documented.
  • Eliminate exposure to hazardous materials (e.g., volatile organic compounds (VOCs) and formaldehyde, and lead and asbestos in older buildings).
  • Provide good indoor air quality (IAQ) and adequate ventilation.
  • Analyze work requirements and provide ergonomic work places to prevent work-related musculoskeletal disorders (WMSD).
  • Perform proper building operations and maintenance.


Provide Designs that Eliminate or Reduce Hazards in the Work Place to Prevent Mishaps

  • Provide designs in accordance with good practice as well as applicable building, fire, safety, and health codes and regulations. See Standards and Code Organizations found at the end of this section.
  • Conduct preliminary hazard analyses and design reviews to eliminate or mitigate hazards in the work place.
  • Use registered design professionals and accredited safety professionals to ensure compliance with safety standards and codes.
  • Provide engineering controls in place rather than rely on personal protective equipment or administrative work procedures to prevent mishaps.
  • Integrate safety mechanisms, such as built-in anchors or tie-off points, into the building design, especially for large mechanical systems.
  • Design a means for safely cleaning and maintaining interior spaces and building exteriors.
  • Provide for receiving, storing, and handling of materials, such as combustibles, cleaning products, office supplies, and perishables.

Prevent Occupational Injuries and Illnesses

  • Consider work practices, employee physical requirements, and eliminating confined spaces when designing buildings and processes.
  • Design for safe replacement and modifications of equipment to reduce the risk of injury to operations and maintenance staff.
  • Comply with applicable regulatory requirements such as the Occupational Safety and Health Administration (OSHA) standards. All OSHA standards are available in the 29 Code of Federal Regulation) (1926—Construction, and 1910—General Industry).
  • Provide proper ventilation under all circumstances, and allow for natural lighting where possible. See High-Performance HVAC and Natural Ventilation.
  • Mitigate noise hazards from equipment and processes.
  • Designate safe locations for installation of RF equipment such as antennas on rooftop penthouses.

Prevent Falls from Heights

  • Provide guardrails and barriers that will prevent falls from heights in both interior and exterior spaces.
  • Provide fall protection for all maintenance personnel especially for roof-mounted equipment such as HVAC equipment and cooling towers.
  • Provide certified tie-off points for fall arrest systems.

Prevent Slips, Trips, and Falls

  • Provide interior and exterior floor surfaces that do not pose slip or trip hazards.
  • Select exterior walking surface materials that are not susceptible to changes in elevation as a result of freeze/thaw cycles.
  • Provide adequate illumination, both natural and artificial, for all interior and exterior areas. See Daylighting and Energy Efficient Lighting.
  • Comply with all regulatory and statutory requirements such as the Americans with Disabilities Act. See WBDG Accessible Branch.

Ensure Electrical Safety

  • Ensure compliance with NFPA 70 National Electrical Code® (NEC).
  • Provide adequate space for maintenance, repair, and expansion in electrical rooms and closets.
  • Provide adequate drainage and/or containment from areas with energized electrical equipment.
  • Evaluate all areas where ground fault circuit interruption (GFI) and arc fault interruption (AFI) devices may be needed.
  • Consider response of emergency personnel in cases of fires and natural disasters.
  • Label all electrical control panels and circuits.
  • Install non-conductive flooring at service locations for high voltage equipment.
  • Specify high-visibility colors for high voltage ducts and conduits.

Eliminate Exposure to Hazardous Materials

  • Identify, isolate, remove, or manage in place hazardous materials such as lead, asbestos, etc.
  • Consider use of sampling techniques for hazardous substances in all phases of the project to include planning, design, construction, and maintenance.
  • Consider occupant operations and materials in designing ventilation and drainage systems.
  • Incorporate integrated pest management (IPM) concepts and requirements into facility design and construction (e.g., use of proper door sweeps, lighting, trash compactors, etc.) and require the use of IPM be performed by qualified personnel during all phases of construction and after the facility is completed. This should include not only interior pest management, but landscape and turf pest management as well. See Sustainable O&M.
  • Provide adequate space for hazardous materials storage compartments and segregate hazardous materials to avoid incompatibility.
  • Substitute high hazardous products with those of lower toxicity/physical properties.
Diagram of a typical ventilation system design for fume hood systems in laboratories. The diagram shows outside air intake moving through the supply fan duct system and then moving into the exhaust hood and then onto the exhaust fan and exhaust stack.

Typical ventilation system design for fume hood systems in laboratories. Air may be supplied through single- or dual-duct constant air volume (CAV) or variable air volume (VAV) systems.

Provide Good Indoor Air Quality and Adequate Ventilation

  • Consider ventilation systems that will exceed minimum ASHRAE standards.
  • Recognize and provide specially designed industrial ventilation for all industrial processes to remove potential contaminants from the breathing zone.
  • Design separate ventilation systems for industrial and hazardous areas within a building.
  • Consider the use of carbon monoxide (CO) monitoring equipment if there are CO sources, such as fuel-burning equipment or garages, in the building.
  • Specify materials and furnishings that are low emitters of indoor air contaminants such as volatile organic compounds (VOCs). See Green Products.
  • Consider the indoor relative humidity in the design of the ventilation system.
  • Avoid interior insulation of ductwork.
  • Locate outside air intakes to minimize entrainment of exhaust fumes and other odors. (e.g., vehicle exhaust, grass cutting and ground maintenance activities, industrial pollutant sources, cooling tower blow-offs, and sewage ejector pits).
  • Ensure the integrity of the building envelope, including caulks and seals, to preclude water intrusion that may contribute to mold growth.
  • Prevent return air plenums/systems from entraining air from unintended spaces.
  • Provide air barriers at interior walls between thermally different spaces to prevent mold and mildew.

Provide Ergonomic Workplaces and Furniture to Prevent Work-Related Musculoskeletal Disorders (WMSD)

  • Design work places that make the job fit the person. See WBDG Functional /Operational Design Objective.
  • Select furnishings, chairs, and equipment that are ergonomically designed and approved for that use.
  • Design equipment and furnishings reflective of work practices in an effort to eliminate repetitive motions and vibrations as well as prevent strains and sprains.
  • Consider using worker comfort surveys in the design phase to help eliminate work-related musculoskeletal disorders.
  • Accept the principle that one size does not fit all employees. See Accessible—Beyond Accessibility to Universal Design.
  • Consider providing break areas to allow the employees to temporarily leave the work place.
  • Minimize lighting glare on computer monitor screens. Provide task lighting at workstations to minimize eye fatigue. See Energy Efficient Lighting.

Perform Proper Building Operations and Maintenance

Proper preventative maintenance (PM) not only improves the useful life of the systems and building structures, but it can lend to good indoor air quality and prevent "sick building" syndromes. See Sustainable O&M Practices.

  • Ensure all maintenance and operation documentation, especially an equipment inventory, is submitted to the building owner/operator prior to building occupancy.
  • Follow manufacturer recommendations for proper building operations and maintenance.
  • Include safety training of operator personnel as part of the construction contractor's deliverables.
  • Require the use of integrated pest management (IPM) for all pest management services, interior and exterior of the building.
  • Require building maintenance personnel to maintain the HVAC air infiltration devices and condensate water biocides appropriately.
  • Monitor chemical inventories to identify opportunities to substitute green products.
  • Consider incorporating continuous commissioning  into your building maintenance program. Federal mandate for continuous commissioning are found in EPAct 2005 and EISA 2007.

Related Issues

Health and Safety of Telecommuting Employees: In January 2000, the Department of Labor said that employers would not be held liable for health and safety violations occurring in the homes of telecommuting employees. See "Department of Labor CPL 02-00-125." The Department of Labor stated that it would not hold employers responsible for health and safety violations that occur in home workplaces other than home offices, for example, fireworks being manufactured in the home, or other activities involving the use of hazardous materials.

example of of cotton-pleated filter

Cotton-pleated filters are possible safe, cost-effective alternatives to conventional fiberglass filters.

Contamination of HVAC Systems: Potential exposure of building occupants to molds from contaminated HVAC systems, especially during maintenance and renovation projects, remains a serious concern. Reaction to exposure can range from negligible to severe among building occupants and can frequently be very difficult to definitively identify as a causal factor for occupants' symptoms. Special care must be exercised in HVAC design, especially, to prevent excessive humidity in system components.

Fiberglass is used extensively in building construction, especially for insulation and sound attenuation in HVAC systems. Considerable concern exists regarding the potential adverse health effects of inhaling fiberglass fibers. A number of studies are currently investigating the long-term effects of inhalation exposure to fiberglass. At a minimum, fiberglass exposed to the air stream in an HVAC system will shed particles and serve as a matrix for collecting dust and dirt that act as a substrate for microbial growth.

Contamination of domestic hot water systems, cooling towers, and condensate pans: continues to result in infections of building occupants on a regular basis. The results of such infections can range from mild to fatal and affect one or many employees. They invariably result in employee apprehension and media attention. Mechanical engineers must be vigilant to avoid system designs that may promote the growth of legionella sp.

Relevant Codes and Standards

Ensure Electrical Safety

Eliminate Exposure to Hazardous Materials

Provide Good Indoor Air Quality (IAQ) and Adequate Ventilation

Provide Ergonomic Work Places to Prevent Work-Related Musculoskeletal Disorders (WMSD)

Perform Proper Building Operations and Maintenance

Additional Resources


Federal Agencies and Programs

Standards and Code Organizations

Associations and Organizations