August 19, 1998

Mr. Mike Lodge
Procedair Industries
625 President Kennedy
Montreal, Quebec, Canada H3A 1K2

Dear Mr. Lodge:

Thank you for your letter of June 1 written as a follow-up to your conversation with Walter Siegfried regarding insulation of metal pipes. Your question was "At what temperature should metal pipe be insulated to avoid burning of the skin on contact?" Mr. Siegfried advised you that there is no specific OSHA standard nor guidelines from which to make this determination. This letter is to confirm that fact and provide you with additional information that might be helpful.

OSHA does consider exposed heated surfaces, if there is a potential for injury, to be a hazard and will issue citations if employees can come into contact with such surfaces. While there are not any OSHA standards, except those that are applicable only to specific industries, which address exposed heated surfaces, there are several OSHA general standards which address such hazards. Those standards are:

1910.261(k)(11):

Steam and hot-water pipes. All exposed steam and hot-water pipes within 7 feet of the floor or working platform or within 15 inches measured horizontally from stairways, ramps, or fixed ladders shall be covered with an insulating material, or guarded in such manner as to prevent contact.

1910.262(c)(9):

Steam pipes. All pipes carrying steam or hot water for process or servicing machinery, when exposed to contact and located within seven feet of the floor or working platform shall be covered with a heat-insulating material, or otherwise properly guarded.

1910.23(c)(3):

Regardless of height, open-sided floors, walkways, platforms, or runaways above or adjacent to dangerous equipment, pickling or galvanizing tanks, de-greasing units, and similar hazards shall be guarded with a standard railing and toe board.

1910.147: The control of hazardous energy (lockout/tagout) standard covers hazardous energy, including thermal, during the servicing and maintenance of machines or equipment. Thermal energy may be dissipated or controlled, and it is the result of mechanical work, radiation, or electrical resistance. This standard addresses practices and procedures that are necessary to disable machinery or equipment and to prevent the release of potentially hazardous energy while maintenance and servicing activities are performed.

1910.132(a):

Protective equipment, including personal protective equipment for eyes, face, head, and extremities, protective clothing, respiratory devices, and protective shields and barriers, shall be provided, used, and maintained in a sanitary and reliable condition wherever it is necessary by reason of hazards of processes or environment, chemical hazards, radiological hazards, or mechanical irritants encountered in a manner capable of causing injury or impairment in the function of any part of the body through absorption, inhalation or physical contact.

The personal protective equipment standard would apply to hot surfaces where the hazards have not been eliminated through engineering or administrative controls. This standard requires employers to assess the workplace to determine if hazards that require the use of PPE are present or are likely to be present. The employer must select and have affected employees use properly fitted PPE suitable for protection against these hazards, as well as provide employee training and conduct periodic inspections to assure procedures are being followed. Suitable thermal protection would be necessary to provide employees with thermal insulation from hazardous hot pipe surfaces.

Section 5(a)(1) of the OSHAct:

Each employer shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.

The private sector has specifically addressed the issue of exposed heated surfaces. The national consensus standard, "Standard Guide for Heated System Conditions that Produce Contact Burn Injuries (C 1055-92)," issued by the American Society for Testing Materials (ASTM) ¹ addresses this issue. The standard establishes a means by which the engineer, designer, or operator can determine the acceptable surface temperature of an existing system where skin contact may be made with a heated surface. Personal injury resulting from contact with heated surfaces can be prevented by proper design of insulation systems or the usage of other protective measures. A copy of that standard has been enclosed for your information.

Also, ANSI A13.1-1975, "Scheme for the Identification of Piping Systems," issued by the American Society of Mechanical Engineers², is enclosed. This standard specifies the identification of the contents of piping systems on the basis of legends and color to warn personnel of outstanding hazards inherent in the materials involved.

Finally, enclosed is an article, "Preventing Burns from Insulated Pipes."³ It answers the question: "What is an acceptable temperature to ensure that no skin burn will occur if a surface is touched?" The article is based on guidelines given by the National Insulation Manufacturers Association (NIMA) and gives the amount of insulation needed to ensure that the acceptable temperature is not exceeded.

Thank you for your interest in safety and health. If you have further questions, please contact the [Office of General Industry Enforcement at (202) 693-1850].

Sincerely,

John B. Miles, Jr.
Director
[Directorate of Enforcement Programs]

[Corrected 1/27/2009]

¹ "Standard Guide for Heated System Surface Conditions that Produce Contact Burn Injuries (C 1055-92)." American Society for Testing and Materials, Philadelphia, PA.[ back to text ]

² Scheme for the Identification of Piping Systems, ANSI A13.1-1975, American National Standards Institute. New York, NY: American Society of Mechanical Engineers.[ back to text ]

³ "Preventing Burns from Insulated Pipes," Chemical Engineering, Vol. 88, No. 15 (July 27, 1981), pp. 58-64.[ back to text ]