It is important to note that OSHA has determined lockout to be a surer means of ensuring de-energization of equipment than tagout, so locks are the preferred method to ensure employee safety. On occasions when a lock cannot be utilized, you need to implement a tagout program. For example, you may have a piece of equipment that uses a plug inserted into a wall receptacle where no electrical control panel exists. In a case like this, you need to implement a tagout program.
According to OSHA's 29 CFR 1910.147 (c)(5)(ii)(C)(2), "Tagout devices, including their means of attachment, shall be substantial enough to prevent inadvertent or accidental removal. Tagout device attachment means shall be of a non-reusable type, attachable by hand, self-locking, and non-releasable with a minimum unlocking strength of no less than 50 pounds and having the general design and basic characteristics of being at least equivalent to a one-piece, all environment-tolerant nylon cable tie."
And, OSHA's 29 CFR 1910.147 (c)(5)(iii) states, "Tagout devices shall warn against hazardous conditions if the machine or equipment is energized and shall include a legend such as the following: 'Do Not Start. Do Not Open. Do Not Close. Do Not Energize. Do Not Operate.'"
OSHA wants to be sure that the tagout program is as safe as a lock-out program would be. In 29 CFR 1910.147(c)(3)(ii), the standard states, "In demonstrating that a level of safety is achieved in the tagout program which is equivalent to the level of safety obtained by using a lockout program, the employer shall demonstrate full compliance with all tagout-related provisions of this standard together with such additional elements as are necessary to provide the equivalent safety available from the use of a lockout device. Additional means to be considered as part of the demonstration of full employee protection shall include the implementation of additional safety measures such as the removal of an isolating circuit element, blocking of a controlling switch, open-ing of an extra disconnecting device, or the removal of a valve handle to reduce the likelihood of inadvertent energization."
The lockout/tagout standard also requires that lockout and tagout devices be capable of withstanding the environment to which they are exposed. Devices that are not exposed to harsh environments need not be capable of withstanding such exposure.
And, tagout devices that have reusable, nonlocking, easily detachable means of attachment (such as string, cord or adhesive) are not permitted.
Next time, I will talk about group lockout/tagout, a procedure that typically is used for complex equipment such as that utilized in the chemicals and petrochemicals industries.