P&P C-37A

Issue Date: 4/16/90
Revised: 11/08/00

AUTHORITY: California Labor Code Sec. 6307, 6313, 6800 and California Government Code Sec. 8574.9.

POLICY: It is the policy of the Division of the Occupational Safety and Health to develop and implement a statewide emergency action plan for responding to Significant Events anywhere in the State of California. Regional and District Emergency Response Investigation Teams will assist federal, state and local Incident Command Systems in managing and investigating Significant Events such as catastrophic incidents, accidents, uncontrolled releases of hazardous substances or natural disasters.



1. Definition

A Significant Event is an incident in which any of the following has occurred or is imminent:

a. Fatal injury to more than one person;

b. A catastrophe as defined in P&P C-170 & 170A, i.e., the inpatient hospitalization, regardless of duration, of three (3) or more employees resulting from an employment injury, illness or exposure caused by a workplace hazard or condition.

c. An uncontrolled release of hazardous materials which has caused, or has the potential to cause, multiple fatalities or serious injuries, illnesses or exposures to three (3) or more employees or three (3) or more members of the general public;

d. Major structural damage to places of employment, that if not controlled, has the potential to cause multiple fatalities or serious injuries, illnesses or exposures to three (3) or more employees or three (3) or more members of the general public; or

e. Any other incident which the Chief, or Deputy Chief for Field Operations, determines constitutes a Significant Event.

2. Emergency Involving Radioactive Materials or Sources of Radiation

a. A Significant Event does not include an incident which solely involves radioactive materials or sources of radiation.

b. The Division shall refer all such incidents to the Radiological Health Unit in the California Department of Health Services (CDHS) for investigation. However, the Division will investigate an incident involving a combination of radioactive materials or sources and non-radioactive chemicals or physical hazards, but only when all radioactive materials or sources have been removed, or adequately controlled at the site, and the area has been deem to be safe from radioactive exposures by personnel from the Radiological Health Unit (CDHS).


1. Imminent Hazard

The Division shall respond to a Significant Event as an imminent hazard.

2. District and Regional Emergency Response Investigation Teams

a. Organization

Each District and Region shall establish and maintain a District Emergency Response Investigation Team (DIT) and a Regional Emergency Response Investigation Team (RIT) which shall contribute to the formation of a Northern and Southern California Inter-Regional Response Group (IRRG) to respond to Significant Event investigations when more than a single RIT is needed.

b. Emergency Response Procedures

Each DIT, RIT and IRRG Team Leader and Team Member shall comply with all procedures set forth in the Division's Emergency Response Field Manual and with the Division's Internal Incident Command System, as specified in the Field Manual.

3. Division Resources and Support

a. Emergency Access

The Deputy Chief for Field Operations shall maintain a current list of telephone numbers for personnel, agencies, organizations and emergency services that may needed to assist in the investigation of a Significant Event.

b. Administrative Services

Administrative Services shall provide appropriate support to District and Regional Emergency Response Investigation Teams during a Significant Event.

c. Management and Compliance Personnel

The Division shall provide qualified management and compliance personnel at the site of a Significant Event through the DIT, RIT or IRRG.

d. Other Division Resources

The Division shall provide all necessary resources to conduct a thorough investigation, including technical support from other units of the Division, such as the Pressure Vessel, Elevator, High Hazard, Research and Standards and Legal Units.

4. State and Federal Incident Command System

During Significant Events, Division personnel shall work within the authority of the California Incident Command System (ICS) and/or the Federal On-Scene Coordinator and Federal Regional Response Team (OSC/RRT) and provide advice, support and assistance to the ICS, OSC/RRT or other agencies.

5. Hazardous Materials Incidents

Division personnel shall conduct activities during a hazardous materials incident in accordance with the provisions of the California Hazardous Material Incident Contingency Plan to prevent occupational safety and health exposures and enforce appropriate safety and health regulations.

6. Communication

Division personnel shall establish and maintain effective coordination and communication with all agencies, employers, employees, employee representatives and with the print and electronic news media.

7. Employee Status

a. Division personnel shall consider all persons, excluding Federal employees or employees under Federal direction and control, who perform any hazardous material emergency response and/or remedial activity associated with a Significant Event at any location, who may be exposed to a hazard, to be employees.

b. Division personnel shall consider volunteers, whether members of an organization, or members of the general public acting independently, who may be exposed to a hazard resulting from a Significant Event, to be employees of the entity having the authority to control access and to permit work and entry into a site.

8. Laboratory Support

Existing contracted laboratory services may be insufficient to support the investigation of Significant Events. Each Regional Manager shall develop and maintain a list of laboratories capable and willing to provide supplemental laboratory support to the Division on an emergency contract basis.


See P&P C-37B.


See the DOSH Emergency Response Field Manual.