Shelter in Place

Shelter in place is an emergency protective action in which people stay inside a building, or move to a designated safe area within it, instead of evacuating. It is used when going outside would be more dangerous than staying in, such as during a hazardous chemical release, severe weather or certain security threats.

Many people think of emergency response only in terms of evacuation. In some emergencies, though, leaving the building exposes people to the very hazard they are trying to escape. A workplace emergency plan that covers both evacuation and shelter in place helps employees respond correctly in the first few critical minutes.

What Is Shelter in Place?

Sheltering in place means using a building as a temporary barrier between people and an outside hazard. Depending on the emergency, it may involve moving to an interior room, closing doors and windows, shutting down ventilation systems and waiting for an all-clear from emergency officials or site leadership.

The CDC has described sheltering in place for chemical emergencies as making a shelter out of the building you are in until help arrives. Shelter-in-place periods for chemical releases are usually short, often lasting a few hours, because outdoor air eventually clears or emergency responders control the source.

Shelter in place is different from a lockdown, although the terms are sometimes confused. A lockdown is a response to an active security threat inside or near the building, such as an armed intruder, and focuses on securing doors and keeping people out of sight. Shelter in place usually refers to environmental or weather hazards outside the building.

When Is Shelter in Place Used?

• Chemical releases: an outdoor release of toxic gas or vapor from a nearby facility, pipeline, rail car or truck, or from a process on your own site.
• Severe weather: tornadoes, hurricanes and other high-wind events where the safest place is a sturdy interior space away from windows.
• Radiological incidents: public health agencies advise getting inside and staying inside during a radiation emergency.
• Wildfire smoke or other poor air quality events: when officials advise staying indoors to limit exposure.
• Security threats outside the building: when law enforcement advises people to stay inside, away from the area of a threat.

Shelter in Place and OSHA Requirements

OSHA does not have a standard titled "shelter in place." Instead, shelter in place is typically addressed as part of an emergency action plan (EAP). Under 29 CFR 1910.38, an employer must have an EAP whenever an OSHA standard requires one. The plan must be in writing, kept in the workplace and available to employees for review, although an employer with 10 or fewer employees may communicate the plan orally.

At a minimum, an EAP under 1910.38 must include:

• Procedures for reporting a fire or other emergency.
• Procedures for emergency evacuation, including type of evacuation and exit route assignments.
• Procedures for employees who remain to operate critical plant operations before they evacuate.
• Procedures to account for all employees after evacuation.
• Procedures for employees performing rescue or medical duties.
• The name or job title of every employee who may be contacted for more information about the plan.

The standard also requires an employee alarm system that uses a distinctive signal for each purpose, designated and trained employees to assist in a safe and orderly evacuation, and review of the plan with each covered employee when the plan is developed, when the employee is first assigned, when the employee's responsibilities change and when the plan changes. Because the "type of evacuation" can include sheltering in place, many employers write shelter-in-place procedures directly into their EAP.

Facilities that handle hazardous chemicals may also have shelter-in-place obligations or expectations under other programs, such as process safety management, HAZWOPER emergency response planning or community emergency planning with local authorities.

How to Shelter in Place at Work Step by Step

Procedures should be tailored to your building and hazards, but a chemical release shelter-in-place response often follows these steps, based on public health guidance:

1. Sound the alert. Use a distinct alarm, announcement or mass notification message that clearly means "shelter in place," not "evacuate."
2. Bring people inside. Move employees, contractors and visitors indoors quickly. Ask visitors to stay rather than leave.
3. Close the building. Shut and lock exterior doors and windows.
4. Shut down air handling. Turn off heating, ventilation and air conditioning systems, exhaust fans and other systems that bring in outside air. Designate trained people to do this.
5. Move to the shelter room. Go to a pre-selected interior room with as few windows and doors as possible. For most chemical releases, a room above ground level is preferred because some gases are heavier than air and collect in low areas. For tornadoes, the opposite applies: go to the lowest level.
6. Seal the room if directed. Close the door and, where your plan calls for it, seal gaps around doors, windows and vents with plastic sheeting and duct tape.
7. Account for everyone. Take a headcount and report missing people to the emergency coordinator.
8. Monitor official information. Use a radio, phone alerts or internal communications for updates, and keep phone lines open for emergencies.
9. Wait for the all-clear. Stay inside until site leadership or emergency officials say it is safe, then ventilate the building and follow any further instructions.

Planning for Shelter in Place

• Assess your hazards. Identify chemical, weather and other threats that could affect your site, including nearby facilities and transportation routes. A risk assessment helps decide which scenarios need shelter-in-place procedures.
• Select shelter areas. Choose rooms large enough for the people expected to use them, with minimal windows and exterior openings.
• Stock supplies. Keep items such as a first aid kit, flashlights, a battery-powered radio, drinking water, plastic sheeting, duct tape and scissors in or near shelter areas.
• Know your HVAC controls. Label shutoff switches and train designated employees on how and when to use them.
• Plan communications. Decide how you will alert employees, contact emergency services, account for workers and receive the all-clear.
• Coordinate with local authorities. Learn how local emergency management will notify your site of community-wide shelter-in-place orders.
• Train and drill. Practice shelter in place, not just fire evacuation, so employees can tell the difference between the two alarms.

Examples of Shelter in Place

• A warehouse near a rail line receives a community alert about a chlorine leak from a derailed tank car. Employees move to a second-floor interior training room while maintenance staff shut down the HVAC units.
• A manufacturing plant activates its tornado warning procedure, and employees move to reinforced interior restrooms on the ground floor until the warning expires.
• An office building is advised by local police to keep people inside during a nearby police operation, and managers keep employees away from exterior windows and doors until cleared.

Common Mistakes to Avoid

• Using the same alarm for evacuation and sheltering: employees may run outside into a hazard.
• Forgetting the ventilation system: leaving air handlers running can draw contaminated air into the building.
• Choosing the wrong room: basement shelter areas may be unsuitable for heavier-than-air chemical releases.
• No accountability process: without a headcount, missing workers may not be noticed.
• Never practicing: plans that exist only on paper often fail under stress.

How SMS360 Helps

The SMS360 Document Library gives teams one controlled place to store emergency action plans, shelter-in-place procedures, floor maps and contact lists, so employees and supervisors can find the current version quickly, including from a mobile device. Version control and review reminders help keep emergency procedures up to date as buildings, hazards and responsibilities change.

Frequently Asked Questions

What is the difference between shelter in place and evacuation?

Evacuation means leaving the building to get away from a hazard inside it, such as a fire. Shelter in place means staying inside to stay protected from a hazard outside, such as a toxic gas release or a tornado. A complete emergency plan explains when each one applies and uses distinct alarms for each.

Does OSHA require a shelter-in-place plan?

OSHA does not have a separate shelter-in-place standard. However, when an OSHA standard requires an emergency action plan, 29 CFR 1910.38 requires the plan to cover emergency procedures, including the type of evacuation. Employers whose hazards call for sheltering in place typically include those procedures in their EAP.

Which room is best for sheltering in place?

For chemical releases, public health guidance recommends an interior room with as few windows and doors as possible, ideally above ground level because some chemicals are heavier than air. For tornadoes and high winds, go to the lowest level in an interior space away from windows.

How long does sheltering in place last?

For most chemical releases, sheltering in place lasts a few hours or less. Employees should stay inside until site leadership or emergency officials announce that it is safe to leave, and the building should be ventilated afterward.