US Dept of Labor

Occupational Safety & Health AdministrationWe Can Help

Standard Interpretations - Table of Contents
• Standard Number: 1910.120

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

January 26, 1993

(Name Withheld)

Dear (Name Withheld):

Your letter of April 17, concerning the Occupational Safety and Health Administration's (OSHA's) Hazardous Waste Operations and Emergency Response regulation, 29 CFR 1910.120, was forwarded to OSHA's [Directorate of Enforcement Programs] for response. We regret the delay in responding to your letter.

You requested clarification and guidance on how training requirements in the Hazardous Waste Operations and Emergency Response regulation (HAZWOPER) apply to plant maintenance personnel, including those with refrigeration system duties.

Generally, the emergency response provisions in 29 CFR 1910.120 paragraph (q) apply to employers who use refrigeration systems utilizing anhydrous ammonia as a cooling agent. Employers must determine if there is a potential for release of ammonia in their facility which could result in an emergency situation, due to the nature of anhydrous ammonia and the refrigeration units in which it is used. Employees who would be expected to participate in an emergency response must be trained in accordance with the requirements described in paragraph (q)(6).

The employer must also meet the requirements of the Hazard Communication Standard, 29 CFR 1910.1200, the Storage and Handling of Anhydrous Ammonia standard, 29 CFR 1910.111, standards for personal protective equipment and other OSHA standards.

We will answer your specific questions in the order that you addressed them:

  1. Plant maintenance personnel may have years of experience and possess a tremendous amount of working knowledge, but have no formal training, but have worked several years safely.

    If there is a potential for a release of ammonia which could result in an emergency situation and plant maintenance personnel would be expected to respond, these employees must receive training in accordance with 29 CFR 1910.120(q)(6). Their previous work experience and informal training may satisfy part of the requirements in the first two levels of training, outlined in 29 CFR 1910.120(q)(6)(i)-(ii). Hazardous materials technicians may not merely demonstrate "sufficient experience" as stated in the first two levels of training, but must have training in addition to the listed competencies. Several years of work without an accident is not sufficient; in this case, formal training in emergency procedures would be necessary.

    Training must be based on the duties to be performed by an employee during an emergency. Employers may choose to train their employees only in the hazards of ammonia. However, employees trained in this limited manner would only be able to respond to spills that involve ammonia. Employers may broaden their employees limited training at a later date if they expect their employees to respond to releases of other hazardous substances.

  2. The response agencies in some communities may not be equipped to help ammonia people.

    When employers feel that community emergency responders are unequipped to handle a release of ammonia, employers should either hire contractors that are in compliance with 29 CFR 1910.120 or find some other means of responding to the release. If employers use their own employees to respond they must ensure that their employees are fully trained and equipped to handle the burden of responding to a release.

    Employers always have the option of not using their own employees to respond to an emergency. They may instruct their employees not to respond, evacuate the work place and call an outside HAZMAT team for assistance. In this case, an Emergency Action Plan must be developed in accordance with 29 CFR 1910.38(a), as stated in 29 CFR 1910.120(q)(1).

    Facilities must notify the Local Emergency Planning Committees (LEPC's) or State Emergency Response Commissions (SERC's) of quantities of "extremely hazardous substances" at or above the designated threshold quantity, as per the Superfund Amendments and Reauthorization Act of 1986 (SARA). The regulation issued by the U.S. Environmental Protection Agency, 40 CFR Part 355, specifies that 500 pounds is the threshold planning quantity for ammonia.

    Community emergency responders, such as fire fighters and police, must work with the SERC or LEPC and, therefore, should be aware of plants that use refrigeration systems utilizing 500 pounds or more of anhydrous ammonia as a cooling agent. You may contact the Emergency Planning and Community Right-to-know Act (EPCRA) Hotline for more information on SARA at [1-800-424-9346 OR TDD at 1-800-553-7672].

  3. What role must the plant operator undertake to assure that outside contractors, [that work] on site doing maintenance, are trained and to what level must they be trained?

    Both contractors and their clients are responsible for complying with OSHA's regulations. Clients must ensure that contractors are notified of conditions which may lead to emergencies.

    OSHA considers providers of personnel, who send their own employees to work at other facilities, to be employers whose employees may be exposed to hazards. Since the contractor maintains a continuing relationship with the employees, but it is the client who creates and controls the hazards (in this case the refrigeration unit) there is a shared responsibility for assuring that employees are protected from work place hazards. The client has the primary responsibility for such protection, but the contractor employer also has a responsibility under the Occupational Safety and Health Act.

    The contractor would be required to provide training and to ensure that employees are provided with medical surveillance if it is necessary. The client would be responsible for providing site-specific training, such as the facility's places of refuge and decontamination areas, and would have the primary responsibility to control potential exposure conditions. It is further the responsibility of both employers to ensure that the client employer is fulfilling its responsibility and is in compliance with the standards. Written contracts between the parties should clearly describe the responsibilities of both parties in order to ensure that all requirements of the regulation are met.

    An employer must comply with the Process Safety Management (PSM) standard at worksites where one or more facilities (i.e. building, container or equipment) contain one or more of the covered processes. Processes involving threshold quantities, or greater, of a toxic or reactive chemical concentration listed in PSM's Appendix A are covered by the standard. With exceptions which are specified in 1910.119(a), processes involving threshold or greater quantities and flammable liquids and/or gases are covered by the PSM standard. When determining whether or not there is a threshold quantity, the amount of each toxic or reactive chemical concentration listed in Appendix A is considered by itself and the amount of flammable liquids and/or gases is considered collectively.

    The PSM standard requires that contract employers ensure that their employees are trained in the work practices necessary to safely perform their job, and are instructed in the known potential fire, explosion or toxic release hazards related to their job. The host employer is required to provide to the contract employer process information and to evaluate periodically the performance of a contract employer in fulfilling these training requirements.

  4. And, finally, how does plant management evaluate the quality of contractor's programs under [29 CFR] 1910.119 as they themselves have no real experience in this program?

    OSHA suggests that the employer review 29 CFR 1910.119 and the standard's preamble to understand specific OSHA requirements. Many employers have found it advantageous to obtain some training, hire an outside consultant, or designate a manager to ensure compliance with regulations. OSHA has published a compliance directive on 29 CFR 1910.119, CPL 2-2.45A, which you may request from the OSHA publications office at the following phone number: [1-800-321-OSHA (6742)]. The employer may also contact its State or Area OSHA office or OSHA Consultation Services to discuss the standard's requirements. (Please see the enclosed booklets.)
We hope this information is helpful. If you have any further questions please contact the [Office of Health Enforcement at 202-693-2190.]


Roger A. Clark,
[Directorate of Enforcement Programs]

[Corrected 4/15/03]

Standard Interpretations - Table of Contents

Thank You for Visiting Our Website

You are exiting the Department of Labor's Web server.

The Department of Labor does not endorse, takes no responsibility for, and exercises no control over the linked organization or its views, or contents, nor does it vouch for the accuracy or accessibility of the information contained on the destination server. The Department of Labor also cannot authorize the use of copyrighted materials contained in linked Web sites. Users must request such authorization from the sponsor of the linked Web site. Thank you for visiting our site. Please click the button below to continue.