Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at

November 14, 1990

Catherine C. Bobenhausen, CIH
Malcolm Pirnie, Inc.
Post Office Box 751
White Plains, New York 10602

Dear Ms. Bobenhausen:

This is in response to your August 17, letter requesting clarification of several emergency response provisions of the Occupational Safety and Health Administration's (OSHA) Hazardous Waste Operations and Emergency Response Standard (29 CFR 1910.120). The answers to your questions are as follows:

1. Question: What are the limits of the phrase "immediate release area"?

Answer: "Immediate release area" is the area, process, or machine which is creating the hazardous spill. In your example, workers in different areas of the plant would be considered outside the "immediate release area." This term is not meant to be used exclusively to determine whether a situation is an emergency under this standard. The key factor which must be considered on a case-by-case basis is the actual or estimated exposure or degree of danger to responders, other workers, neighbors, etc. In order to determine this, factors such as the size of the spill/release, the material spilled and the location of the incident (e.g., confined space) play a significant role. While it may be obvious, it is crucial that planning take place prior to any emergency incident. An employer must determine all likely potentials for emergencies using worst-case assumptions and plan response procedures accordingly.

2. Question: Would the standard be applicable if an employee who happens to be present when an incidental spill occurs, but who does not normally work in that area, helps cleanup the spill?

Answer: Employees responding to incidental spills must have the proper equipment and training under other OSHA standards such as the Hazard Communication Standard (29 CFR 1910.1200).

3. Question: How does OSHA define an "uncontrolled release" of a hazardous substance?

Answer: Uncontrolled release is the release of a hazardous substance from its container. If not contained, stopped, and removed, the release would pose a hazard to the employees in the immediate area or in areas in the path of the release, or from its by-products or its effect (such as toxic vapors, fire, over-pressurization, toxic gases, or toxic particulate).

4. Question: Can maintenance personnel from any area of the plant respond to clean up a spill without being subject to the emergency response provisions of 29 CFR 1910.120?

Answer: Maintenance personnel who may respond to an emergency or potential emergency are covered by the emergency response training under 29 CFR 1910.120. For maintenance personnel who only respond to incidental spills, training under other OSHA standards (e.g., Hazard Communications Standard) would be necessary.

5. Question: How is "incidental release" interpreted?

Answer: Incidental release is one that does not cause an imminent health or safety hazard to employees and does not have to be cleaned-up immediately to prevent death or serious injury to employees.

6. Question: What is meant by the phrases "no potential safety or health hazard" and no "chemical exposure"?

Answer: Your letter does not provide us with the specific sections of the standard you are referencing. A general answer is there is virtually no likelihood that employee(s) could be injured or exposed to a hazardous substance in the event of an uncontrolled release.

Please feel free to contact us again if we can be of further assistance.


Gerard F. Scannell
Assistant Secretary