There is really no excuse for exposure to unguarded heating process equipment that endangers factory and plant workers — the U.S. Occupational Safety and Health Administration is quite clear about that. Not enough is being done to raise awareness about injuries and how they come about.

Industrial injuries happen all the time, and it would be unwise to shrug these off merely because they have not happened in one’s own plant before. Insurance companies certainly make it known that customers need to take risk assessments but may be scant on details of what exactly needs to be assessed.

Plant owners and managers need to understand that once an injury occurs, the process of denying an insurance claim and any consequent court action is purely reactive and based on the premise that the possibility of injury should have been foreseen. There is little proactive effort on their part other than their published guidelines and the publicity given to previous cases.

21 Types of OSHA-Compliant Lockout/Tagout Devices Protect Workers from Unguarded Hazards

OSHA requires that control of hazardous energy be performed according to a six-step procedure: preparing for shutdown, shutting down equipment, isolating all energy sources to the equipment, fitting locks and tags, releasing stored energy and verifying that equipment is isolated.

An effective example of a lockout procedure is to fully isolate an energy source ahead of maintenance work, which would entail identifying the energy source, isolating it, and then locking and tagging it to prove the equipment is isolated. These locks should not be removed until the work is completed, and each engineer has signed off that work is completed.

There are many kinds of lockout devices available on the market, each of which is suitable for a different application. OSHA-compliant devices include lockout hasps, cable lockouts, valve lockouts, gas cylinder lockouts, pneumatic lockouts, plug lockouts and circuit breaker lockouts. 

For further information please visit PASS Ltd.'s dedicated OSHA lockout/tagout website,, which provides a guide to lockout equipment in 21 product categories.

The OSHA standard for the control of hazardous energy (lockout/tagout) for general industry — also known as 29 CFR 1910.147 — outlines specific actions and procedures for addressing and controlling hazardous energy during servicing and maintenance of machines and equipment.

The first place to look at is OSHA’s website on its page entitled “Control of Hazardous Energy – Lockout/tagout,” particularly the fact sheet and the section entitled “What can be done to control hazardous energy?” These address the practices and procedures necessary to disable machinery or equipment, thereby preventing the release of hazardous energy while employees perform servicing and maintenance activities.

OSHA warns that injuries may include electrocution, burns, crushing, cutting, lacerating, amputating or fracturing body parts. In the specific case of process heating, OSHA cites the example of a steam valve that may be automatically turned on, burning workers who are repairing a downstream connection in the piping.

LOTO to Prevent Burns During Steam Generation

OSHA will offer specific advice — offered as standard interpretations — to companies that take precautionary steps to investigate their injury risk. For instance, in a letter to Comtec International in 2007, OSHA addressed its steam generation scenario. 

The scenario described a steam generation facility that produces and distributes steam at 135 psi gauge to a number of facilities for heating, humidity control and processes, with access to valves, traps and system components provided through a number of steam vaults, or pits, located at points along the distribution grid.

Comtec asked whether, with the steam system charged and at steady-state condition, there was an engulfment hazard for entrants who operate components such as valves on the pressurized steam system within the steam pit.

OSHA replied that its Permit-Required Confined Spaces (PRCS) standard requires that the hazard be isolated and defines isolation as “the process by which a permit space is removed from service and completely protected against the release of energy and material into the space by such means as: blanking or blinding; misaligning or removing sections of lines, pipes, or ducts; a double block and bleed system; lockout or tagout of all sources of energy; or blocking or disconnecting all mechanical linkages.”

Lockout/tagout, if applicable, is probably the cheapest and quickest of all these methods. Replying to a question about whether the steam system pressure/temperature double-valve isolation is required for above-ground work, OSHA explained that section 1910.147 is a performance-oriented standard and, as such, does not contain specific temperature or pressure criteria.

Rather, the lockout/tagout (LOTO) standard applies in cases where energy (e.g., thermal energy) may be released in quantities or rates that could injure employees during the servicing and maintenance of machines or equipment.

Continued verification of isolation is required if there is a possibility that hazardous energy may reaccumulate. The likelihood of hazardous energy reaccumulating is greater when a single valve is used for control purposes rather than a double-block-and-bleed form of isolation.

OSHA encourages the use of a double-block-and-bleed isolation method for LOTO purposes as it is a recognized best practice. With respect to the lockout/tagout standard, the use of double valve isolation is not required since the standard’s energy control provisions differ from the permit-required confined spaces isolation requirements.

Adding Pipe Insulation to Prevent Steam and Hot Water Piping Burns

In another interpretation, OSHA replied to a question from Procedair Industries regarding the temperature at which metal pipe should be insulated to avoid burning of the skin on contact, advising that there is no specific OSHA standard nor guidelines from which to make this determination.

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

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.

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.

Failure to LOTO Before Servicing Cooling Fans Leads to Death

Despite the availability of OSHA guidance, injuries and deaths continue to occur, and the focus of subsequent investigations will invariably include possible breaches of LOTO standards. As recently as December 2011, a worker was killed at Action Electric under a contract with a steel mill in Cartersville, Georgia, to replace seventeen fans at the cooling bed during a shutdown.

An Action lead electrician and an apprentice went into the cooling bed basement to discuss replacing the last three fans. While discussing their work, a counterweight that provided movement to the racks on the cooling bed fell from an upright position to the down position when the steel mill maintenance technician initiated the mill lockout procedures.

When the counterweight fell, the apprentice was fatally struck from behind and it narrowly missed the lead electrician. As a result of an inspection by the Occupational Safety and Health Administration (OSHA), Action was issued a serious citation in May 2012.

OSHA alleged that Action violated 29 CFR 1910.147 by failing to train its employees on the purpose and function of an energy control program and by failing to affix personal LOTO devices on the group lockbox before the employees began servicing work on the fans.

Action successfully contested the applicability of 1910.147 LOTO standards because at the time of the accident the employees were not servicing the fans and the counterweight was not connected to or associated with the operation of the fans.

Don't Forget PPE: Vacuum Dryer Boilout 

Similarly, back in 2000 when an employee at BF Goodrich Hilton Davis (BFG) suffered 47 percent body burns when emptying the boilout from a vacuum dryer, OSHA cited LOTO standard violations amongst others. Although it succeeded in defending against the LOTO violation, it was found to have failed to provide employees with personal protective equipment (PPE) to prevent thermal and chemical burns.

In conclusion, whatever is found to cause injury or death, the foregoing investigation will almost invariably raise the question of whether LOTO standards were violated.

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