U.S. Department of Labor

Assistant Secretary for
Occupational Safety and Health
Washington, D.C. 20210

DOL Seal

August 27, 2010

Dear Sir or Madam:

I am writing today to inform you of the hazards associated with the practice of cleaning fuel gas piping systems using natural gas. On February 7, 2010, a devastating explosion at the Kleen Energy power plant in Middletown, Connecticut took a massive human toll, killing six workers and injuring another fifty. This explosion was triggered by the ignition of pressurized natural gas that was being used to clear newly constructed fuel pipes. After a comprehensive inspection of the incident, OSHA recently issued citations with proposed penalties totaling more than $16.5 million. This tragedy could have been easily avoided by the exercise of common sense, adherence to OSHA standards and industry-accepted safety procedures, and following internal safety rules.

As an employer, you are responsible for eliminating or controlling hazards that may kill or injure your employees in these facilities. It is the responsibility of all employers, particularly those operating in high hazard industries, to ensure the safety and health of their employees at the worksite. None of the major employers at the Kleen Energy site on February 7, 2010, took appropriate action to eliminate or reduce hazards associated with fuel system gas blows, despite knowing of the potential fire and explosion hazards associated with such operations. The employers had reviewed and approved safety procedures for conducting these operations. OSHA's investigation, however, determined that many of these precautions were not followed.

The practice of using natural gas blows to clean piping systems is inherently dangerous. The United States Chemical Safety Board, which also investigated the blast, recommended that employers be prohibited from releasing flammable gas to the atmosphere for the purpose of cleaning fuel gas piping.1 There are feasible alternatives to cleaning gas fuel piping with natural gas; these alternatives include the use of non-flammable, non-explosive media to clean the pipes. OSHA strongly recommends the use of non-flammable, non-explosive alternative media when it is necessary to use gas to clean piping.

If you, as an employer involved in building or renovating gas powered electrical generation plants, nevertheless elect to use a gas blow procedure using natural gas, you must evaluate and address all potential hazards before and during the blows, and take effective action to eliminate employee exposure to those hazards.

Specifically, you should vent the natural gas vertically and above all structures, eliminate all ignition sources, remove all non-essential workers from the site, and monitor potentially hazardous atmospheres during and after completion of the blows. At a minimum, the following requirements apply to these operations:

29 CFR 1926.20(b)(2) - The employer must provide a competent person able to recognize construction workplace hazards, including those associated with natural gas blows.

29 CFR 1926.21(b)(2) - The employer must train employees to recognize construction workplace hazards, including those associated with natural gas blows.

29 CFR 1926.352(c) - The employer must ensure that welding, cutting or heating at construction sites is not conducted in the presence of flammable compounds, including natural gas.

29 CFR 1926.403(b)(2) - The employer must ensure that listed, labeled, or certified equipment at construction sites is used in accordance with instructions included in the listing, labeling, or certification (prohibit the use of equipment that can ignite natural gas).

Section 5(a)(1) of the Occupational Safety and Health Act - The employer must keep its workplace free from recognized hazards causing or likely to cause death or serious physical harm. The hazards of natural gas blows are well-recognized in the power plant construction industry. This letter provides individual employers with direct knowledge of the hazards.

It is imperative that you carefully evaluate all aspects of natural gas fuel system blows and follow through with the implementation of all needed safety procedures. If you are a subcontractor at such a site and are not directly involved in the gas blows, you must nevertheless ensure that your employees are fully protected.

It is your responsibility to comply with the law and to fully protect workers at these sites. Any failure to adhere to the law and industry-accepted safety standards in the course of a fuel system gas blow will be pursued vigorously by Federal or State OSHA agencies to the fullest extent of the law. The intent of this letter is to ensure your knowledge of the inherent dangers of fuel system gas blows as well as the safety requirements OSHA expects to be observed. If OSHA finds violations of these requirements, it will strongly consider citing for willful violations that carry a maximum $70,000 civil penalty. If any employee dies as a result of an explosion associated with a gas blow, in addition to any civil penalties proposed, OSHA will consider referring the incident to the Department of Justice for criminal prosecution pursuant to the criminal provisions of the Occupational Safety and Health Act of 1970.

States operating State Plans will consider similar action under State law. Federal OSHA and States that operate their own OSHA-approved State plans are responsible for enforcing occupational safety and health laws and standards throughout the nation. Twenty-seven States and territories operate OSHA-approved State Plans. If you are building or renovating a gas powered electrical plant in any of these States, the State will enforce similar requirements in the private and public sectors. Contact and background information on State standards and enforcement programs may be found at http://www.osha.gov/dcsp/osp/index.html.

I am calling on you today to prevent further needless deaths. If you are a small business, OSHA State On-site Consultation Programs are available to assist you in complying with OSHA standards. If you have further questions, please contact your local OSHA Area, State Plan Office or your State On-site Consultation Program. More information is available at www.osha.gov.



David Michaels, PhD, MPH


1 The Board's full recommendation is found here: http://www.csb.gov/UserFiles/file/FINAL%20Urgent%20Recommendation.pdf (PDF)