26/07/2013

Maximising Lock-Out/Tag-Out Safety

Lock-out/tag-out (LO/TO) procedures exist to prevent workers being killed or injured by the machinery they may be working on. But a poor choice of equipment can make this process cumbersome and ineffective. Kieran MacCourt of Master Lock Europe explains why using only dedicated LO/TO equipment is essential to help manage risk effectively.

In any situation where people trust their lives to their equipment, it would be surprising not to insist on the highest possible quality standards. Yet when it comes to LO/TO safety padlocks, although high-quality products designed for industrial safety use are available, it is still not unusual for firms to opt for cheaper, shop-bought alternatives - an economy which may unwittingly be placing their workers in extreme danger.

The concept of LO/TO is deceptively simple: turning off the source of energy for a machine or process and physically locking it. Yet while the idea might be simple, implementing it reliably often is not. Inadequate equipment and human nature can conspire to create a lethal combination in the workplace.

Choose the Right Equipment

The easy availability of the familiar padlock in any hardware store creates a tempting ‘quick fix’ solution for LO/TO. But far from making the workplace safer, this kind of ad-hoc lock and key control introduces real dangers. Low quality locks not designed for demanding industrial environments are often difficult to use and wear-out quickly, making it much more likely that, eventually, the essential physical lock-out of dangerous machinery will be skipped.

General purpose padlocks have comparatively simple locking mechanisms and few key combinations, meaning that the chances of keys other than the original being able to unlock it are surprisingly high. A recent survey carried out by Master Lock in an Australian mine, revealed that out of a batch of thirty shop-bought padlocks used for LO/TO purposes, no fewer than thirteen keys opened more than one lock; and three keys opened more than two! General purpose locks are usually supplied with more than one key, and there are usually no restrictions on the creation of duplicate keys. Having multiple, viable keys in circulation increases risks logarithmically.
 
Not being clearly identifiable as safety devices introduces another element of danger. Best practice dictates that any device used for lock-out purposes should be singularly identifiable as such and be the only device used for this purpose. An unmarked locking device gives no indication of its purpose, thereby increasing the chances that it might be mistaken for a device placed in error and subsequently removed.

Designing-out Operational Inefficiencies Helps Reduce the Human Factor

The natural human tendency to follow the path of least resistance represents perhaps the biggest threat to any safety procedure. Busy workers do not like to be delayed; shift managers and company bosses want to minimise downtime and get production moving again. In LO/TO any deviation from the ‘one worker, one padlock, one key’ concept introduces an element of risk. But for operational reasons, the use of multiple locks and keys is often unavoidable.

Situations requiring several different energy sources to be locked-out simultaneously require workers to carry around numerous keys, the frustration of which may increase the temptation to cut-corners during routine maintenance tasks. The risk of a key being mislaid is also high, meaning duplicate keys need to be kept on site: more keys means more danger. 

A big advantage of using purpose-made safety padlocks is that they can be managed in a keying hierarchy. Each employee is assigned a unique key code, allowing more than one kind of ‘keyed-alike’ device or different colour codes to be used, but all requiring just a single personal key to open. Within groups of locks, it is possible to have master keys which will open subsets of locks to allow a shift leader to manage locks within their own area of responsibility with a single key, while preventing access to others or the need for duplicate keys.

Moving away from a system based on generic locks with physical keys to one based on dedicated devices and personal key codes, allows flexibility while remaining robust. Some lock manufacturers maintain databases of customer’s individual keying schemes so that they can ensure that no duplicate keys are in circulation within the organization, and that every key change or addition is properly tracked and audited.

It is never possible to totally eliminate risk in industrial environments, but with the right equipment and procedures, it is certainly possible to reduce that risk dramatically. LO/TO procedures make a big difference to workplace safety, but it is important to remember that the padlock hanging on the circuit breaker is the end result of a robust LO/TO system, not the beginning.

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