New legislation makes workplace safety everyone's responsibility. And it's a troublesome balancing act. Everyone wants their workplace to be safe. -But How? And how much will it cost? And how far do we go? And how will we know when it's safe?
There are heaps of laws, standards, regulations, codes of practice and opinions. It can certainly be confusing.
Everybody is asking questions about what is required. In truth, the requirements vary with each situation, but the method of attacking the problem can be applied to most cases. We try to demystify some of the most commonly asked questions in this series of FAQ.
In line with public expectation, modern laws, standards & corporate requirements have re-defined the whole idea of safety. Where it was mostly concerned with avoiding injury to a machinery operator, safety is now considered to be:
Australian regulations state that safety issues need to be considered for all plant and machinery during each stage of it's life cycle including:
Current Australian legislation on machinery safety implicates all stakeholders. Those required to contribute to machinery safety include (but are not limited to):
Your legal obligations apply whether or not your are aware of them -the law states that ignorance is no excuse. The onus is on every individual to find out what their responsibilities are.
There are many things that can contribute to safety;
(We always carry a spare wheel in our car. A twin engine plane is considered safer than a single engine one)
Managing safety for machinery involves examining what can occur if a component fails to operate properly. The simplest way to avoid difficulty is if there is a "spare" available to perform the function.
There are various ways to assess and evaluate the safety requirements of machinery. Safety Standards document recognized methods of ensuring that a safety issue has been properly examined and addressed.
Australian laws require employers to provide a safe work environment. Injury, death or damage in the workplace can result in massive fines and/or jail. The actual detail of the law is covered by various state and federal government legislation. The laws can be applied at any time but are often only applied after an incident. When this happens, it is assumed that the machinery was unsafe - all that remains is the blame - how, why and who was culpable.
In order to apply reasoned argument to safety issues, authorities generally refer to the appropriate Australian Standards. These are used by industry, government, legal and safety experts to ensure the most appropriate care and precautions are taken.
There are various Standards bodies throughout the world who document procedures for all types of jobs and equipment. They are updated from time to time as new information and better technology is introduced. Australian Standards are developed by Standards Australia.
For Australian machinery/plant/equipment, there are various Australian Standards. You should check to see which ones are relevant. If machinery/plant/equipment is to be sold or used overseas, there may also be requirements in the destination country.
Europe is often considered the leader in formulationg standards to be globally acceptable. The European Union (EU) has had to "harmonise" many standards and now other international organisations (including Standards Australia) are beginning to consider where global specifications may be adopted. Progress is being made. Many international standards are now closely related, however Standards Australia remains the peak body for local reference.
Safety of machinery is covered by AS 4024.1 (2006).
This standard is applicable to all machinery.
Pneumatic systems are covered by AS 2788 (2002). There are many electrical standards covering different topics. Check to see what may be relevant. A good place to start is AS/NZS 3000:2000 (Electrical Installations).
Machinery with more specific dangers are covered by more specific standards. Some of these include;
In the past, standards often "preached" an exact specification. Nowadays, most standards aim to be less rigid. Throughout the world, they are being written to encourage the acheivement of compliance by following a procedure of analysis and problem solving.
Safety standards should be applied by reading the methodology and considering all of the processes in the context of each individual workplace situation. The idea is to:
No. Safety laws in Australia are made by the federal, state and (ocasionally) local governments. Standards are developed to help people comply with the law. They are often used in legal situations to help define correct procedures and laws can refer to standards for explanation of the correct way to fulfil your obligations. As such, they do have a role to play in the application of the law
There is a standard for pneumatic systems (AS 2788, 2002) however it doesn't deal specifically with safety or the use of pneumatic components.
In AS 4024.1 (2006), pneumatic components are often treated the same as electrical, hydraulic, mechanical or electronic components. This makes the text simpler and allows the theory to be applied "across-the-board". It is worth noting that pneumatic components differ in several ways from other equipment:
Power presses are amongst the most dangerous of machinery. Any machine which can squash metal with many tonnes of force in a fraction of a second needs to be treated extremely carefully.
This is why a specific standard applies to power presses. AS 1219 (1994) details many important requirements for press safety. This is referred to as a "C" type standard which means it should be applied to all press machinery in addition to the more general "A" & "B" type standards which are also applicable.
Therefore press safety is covered in a general manner by AS 4024.1, and a more specific manner by AS 1219. Presses are generally classified as "Category 4" machinery under AS 4024.1.
For more info on pneumatic requirements specified in AS 1219 (1994) click here (opens new window - you may have to "allow blocked content" by clicking at the top of the page) or refer to AS1219.
Many presses operate by releasing a brake and using a clutch to engage a flywheel. Generally this is done by applying air to override a spring. A valve is used to apply the air in order to stroke the press. This valve is the critical link in the control of the press. Regardless of what other mechanical, electrical or electronic precautions are on the press, if this valve passes air, the press will stroke. For this reason, a special valve is used.
A press safety valve should have 2 valve elements which are operated simultaneously (built-in redundancy). The air flow path should be in series to the press and in parallel for the exhausting air. This means that both valve elements should operate to apply air - but either valve element can exhaust air. (For an explanation of safety valve flowpaths, click here - opens new window - you may have to "allow blocked content" by clicking at the top of the page.) In addition, if both elements don't operate simultaneously, this indicates a problem, and should prompt the inhibition of further operation of the press. This is achieved by monitoring the operation of both valve elements, and halting further press activation if any anomaly is detected. This is referred to as "locking out" the press.
The design and operation of press valves is required to meet some quite specific stipulations. More details are available by careful reference to applicable standards. eg AS 1219 and AS 4024.1.
For more info on pneumatic requirements specified in AS 1219 (1994) click here (opens new window - you may have to "allow blocked content" by clicking at the top of the page) or refer to AS1219.
At home, you wouldn't dismantle an electrical appliance without unplugging it from the power point. Similarly, workplace machinery should be able to be isolated from all energy sources. This includes electrical, hydraulic, pneumatic and any other source of energy the machine may have (including stored energy like electrical capacitors, mechanical flywheels, pneumatic reservoirs etc)
The requirements for isolation will vary in different circumstances but may include the need for:
Pneumatic energy can be problematic because of the time it takes to exhaust air pressure. This needs to be taken into account when isolation is considered.
The circumstances will vary with each application, but general considerations for pneumatic energy isolation include:
Risk Assessment is a tool consisting of a number of steps to help ensure that:
Hazards in the workplace should be eliminated where possible. Where a hazard can't be eliminated, it should be controlled or reduced by (in order):
A Safety Control System is anything that has a bearing on safety. It includes all the components & procedures and their installation and operation. The Safety-Related Parts of a Control System is not limited to electrical switches or logic devices -it incorporates pneumatic, hydraulic and mechanical devices involved in performing safety functions.
Redundancy is where a component's function is duplicated so the system has a "back-up" which can perform the safety function in the event of a fault. This concept of having a "spare" always available is considered one of the best ways to guard against potential problems.
Monitoring is a way to confirm that a component is performing it's required function. It is important to be aware if there has been a problem in a safety device.
"Dynamic monitoring" is where the mechanical parts that perform the monitoring function move with the motion of the normal operation of the component being monitored. This is done to help ensure that monitoring is occurring with every cycle of the component.
Yes. Conventional monitoring is generally used in electrical applications. This is standard "fault" monitoring. In applications involving mechanical or fluid power functions, it is important to include "diminished performance monitoring" which acknowledges that a valve or component can become "sluggish" or "sticky" whilst still being operational. This indicates that a full operational failure is more likely and can also effect overall stopping time for a safety application.
"Overall Stopping Time" is the time it takes for the Safety Control System to halt the hazardous motion of a machine. It is the total response time of all the components and circuitry involved in stopping the machine (usually measured in milliseconds).
"Validation" is a process to confirm that the Safety Control System will meet the assessed safety requirements of a machine. It involves verifying the design and performance specifications of all parts of the Safety Control System and documenting the results.
Unexpected or Unintended Start-up is where machinery commences operation from an event like component failure, external influence, accidental start command or power restoration after interruption. This can potentially be extremely dangerous.
Energy Isolation is often used to prevent unexpected Start-Up. Proper design of safety components and their controls can reduce the chances of other failures or accidents resulting in unexpected or unintended Start-up.
"LOTO" stands for Lock-Out/Tag-Out. This involves literally locking and tagging machinery (often isolating energy supply in the process) as a way of ensuring machinery is not inadvertently started when it has been shut down for maintenance or other reasons.
"Fluid Power" can include any "fluid" source of energy but is mainly used in industry to refer to hydraulic and pneumatic (compressed air) power sources.
In a pneumatic system (unlike electric or hydraulic), the power medium (compressed air) is exhausted out into the atmospheric air when not required. This means that the system is not de-energised until the air is exhausted. It also means that the time taken to exhaust pneumatic devices affects safety functions including speed-of-operation and stopping times.
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