The main reason we perform lockout/tagout procedures is simple – we’re preventing potentially hazardous energy sources from injuring those working in an environment.
What is Hazardous Energy?
When a lot of us think of energy, we’re most likely to think of electricity. We all know it powers our machinery, appliances, lighting and all kinds of other things, and we also know that electrical energy can be extremely dangerous as well.
Electrical energy isn’t the only form of energy though, and there are various different energy forms that can all be deemed hazardous.
Hazardous energy is basically defined as an energy source reaching such a level of build-up that it can cause injury to those working around it. Most energy sources have fail-safes to guard against these eventualities, but in the case of lockout/tagout, hazardous energy is much more dangerous.
Hazardous Energy and Lockout/Tagout Procedures
Lockout/tagout procedures are used as a means of preventing the hazardous energy found in various forms from reaching a level that might be extremely dangerous.
By preventing energy from becoming a danger, the working environment becomes much safer, and allows maintenance/service teams to work comfortably on equipment without fear of the machinery hurting them.
Every year hundreds, if not thousands of deaths take place because lockout/tagout is not correctly enforced, and hazardous energy is allowed to become an extreme danger. By implementing a lockout/tagout procedure that adheres to all rules and regulations, you stop this from occurring, make sure employees are protected and stop nasty accidents and fines from being thrown your way.
Hazardous Energy Forms
As we’ve said previously, hazardous energy is present in many different forms. This section is designed to give you more information about each of these energy sources, and it is absolutely imperative you know about all of them and assess which might be a danger in your particular working environment.
Potential Energy
This energy form can be one of the most overlooked. Potential energy is basically energy that is stored, and can be present inside everything from compressed springs to electrical transformers. When left unchecked, this type of energy can be converted into various other kinds of energy, leading to a hazardous working environment.
As part of the lockout/tagout procedure, it is important to not only power down a machine and lock it out to prevent access, but it is also extremely important for the potential, stored energy that may be present to be fully locked out or – ideally – siphoned away altogether.
The basic rule to follow is to make sure there is absolutely no way for a machine to be powered on when someone is working on it, and that there is also no way for potential energy to damage anybody working on the machine as part of a maintenance/servicing procedure.
Kinetic Energy
Kinetic energy is basically potential energy that has been given the chance to move. The term kinetic actually means ‘of, relating to, or resulting from motion’ and in the case of hazardous energy, kinetic energy being allowed to manifest can result in de-energised machinery suddenly moving, and ultimately result in a potentially nasty accident.
Kinetic energy is very different from other energy sources because it can be directly affected by factors such as gravity. For example, a large press used in an industrial setting could be subjected to gravity at some point, and the press could be pushed down when someone is under it, even if the usual energy source is powered down.
Steps to negate kinetic energy include the use of devices that fit in machinery and stop their movement. We can’t stress enough how important it is that this energy form isn’t simply glossed over – accidents can and will happen thanks to the potential kinetic energy present within machinery, and it is important you treat this hazardous energy form with the respect it deserves.
Flammable Energy
We all know how dangerous fire is, but we also know how unpredictable it can be. Fire can come from seemingly nowhere, and in dangerous environments where flammable substances such as gasses, chemicals or other types of potentially flammable items are used, the risk of flammable energy becoming a hazard is vast.
For example, the presence of a particular solvent used in a machine could suddenly combust, which could present a massive fire risk to both the building and employees. Another example might result in a machine suddenly exploding, which has been known to happen when steps have not been taken to prevent the combustion of flammable energy.
In order to prevent this from becoming a hazard, you must assess, and take steps, to lock out or remove flammable energy in the form of gasses, liquids, solid chemicals and vapours. Don’t neglect any of them – lives could be on the line.
Chemical Energy
This type of energy refers to a potential change that can take place as a result of a chemical substance going through a chemical reaction, bringing about some form of transformation.
Chemical energy is extremely, extremely dangerous. Chemical reactions are behind a lot of the dangers we can potentially face in working environments ranging from something like getting acid on the skin to fire reacting with an invisible gas and causing a massive explosion.
It is therefore important when conducting lockout/tagout procedures that any potentially damaging chemical reactions are known about, and steps are taken to fully prevent them from ever taking place.
Electrical Energy
Electrical energy actually has to be created to be present, and comes about as a use of mechanical, thermal or chemical energy. Once it has been created, electrical energy becomes dangerous and – although it is usually kept in check – countless accidents have happened over the years because of electricity.
In a working environment, electricity is most likely to be used to power a piece of machinery. It is important during your lockout/tagout procedure that the power source is turned off, all electrical energy residues are removed and the system is fully locked out to prevent re-energisation.
Generally electrical energy comes from sources such as open busbars, motors and generators, and the energy can also be classed as ‘potential’ because it has the power to flow and be stored.
Thermal Energy
Thermal energy refers to any incident where energy can be transferred from one body to another as a result of a temperature difference. Thermal energy therefore refers to both cold and extremely hot temperatures, and in terms of lockout/tagout, it is important that thermal energy is taken into account.
For example, a super-heated piece of machinery would have to be left to cool down during maintenance, as otherwise there’s a severe risk of burns.
Sources of this energy include mechanical work, radiation, chemical reactions and electrical resistance.
