According to OSHA's lockout/tagout compliance directive, employers must provide effective initial training, effective retraining as needed and certification of training. This certification should include each employee's name and the dates the training took place.
Retraining of authorized and affected employees (for a review of employee-ype definitions, see Process Heating, April 2003, page 22) is required:
- Whenever there is a change in employee job assignments.
- Whenever a new hazard is introduced due to a change in machines, equipment or process.
- Whenever there is a change in the energy control procedures.
- Whenever a periodic inspection by the employer reveals inadequacies in the company procedures or in the knowledge of the employees.
In 29 CFR 1910.147(c)(4)(i), OSHA mandates that all employers develop and document procedures and techniques to be used for the control of hazardous energy. Only those that OSHA certifies as qualifying for an exception are exempt from this requirement. To receive an exemption, eight conditions must exist:
1. The machine or equipment has no potential for stored or residual energy or re-accumulation of stored energy after shutdown that could endanger employees.
2. The machine or equipment has a single energy source that can be identified readily and isolated.
3. The isolation and locking out of that energy source will completely de-energize and deactivate the equipment.
4. The machine or equipment is isolated from that energy source and locked out during servicing or maintenance.
5. A single lockout device will achieve a locked-out condition.
6. The lockout device is under the exclusive control of the authorized employee doing the servicing or maintenance.
7. The servicing or maintenance does not create hazards for other employees.
8. The employer, in utilizing this exception, has had no accidents involving the unexpected activation or re-energization of the machine or equipment during servicing or maintenance.
It is critical to note that each circumstance is different, and each is open to interpretation by OSHA. For instance, a letter of interpretation from OSHA to a safety consultant who asked to apply the exception, reads in part:
...Specifically, you want to apply the exception listed under 29 CFR 1910.147(c)(4)(i) and believe that the company has met all eight of the "exceptions."
The OSHA standard 29 CFR 1910.147...covers the servicing and maintenance of machines and equipment in which the unexpected energization or start up of the machines or equipment, or release of stored energy could cause injury to employees. Since the natural gas, which is used to heat the oven, poses a potential thermal energy hazard for employees who are performing maintenance or servicing activities, the provisions of 29 CFR 1910.147 are applicable. Further, the exception [rule] is inapplicable to the situation that you have described. Since it appears that the oven has at least two energy sources, and it is unlikely that a single lock-out device can be used to effectively lock-out the oven, at least two of the eight conditions which are essential to the application of the exception are not met.
29 CFR 1910.147(b) defines "energy source" as, any source of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other energy. Since the natural gas is used to heat the oven, it is an energy source. Since natural gas, if unexpectedly released and ignited, would produce potentially hazardous thermal energy, an eenergy control procedure is required to address the potential hazards associated with the natural gas.
Every heat processing application, by its nature, will have thermal energy sources, so do not rely on exceptions, hoping to "get away" with less strenuous record keeping.
Next time, I will discuss lockout vs. tagout and bring you a roundup of the types of devices that can be used to control hazardous energy sources.