machinery safe use an introduction

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Safe Use of Machinery -An IntroductionNOVEMBER 2012


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More information

www.mbie.govt.nz

0800 20 90 20

Information, examples and answers to yourquestions about the topics covered here canbe found on our website www.mbie.govt.nz or by

calling us free on 0800 20 90 20.

Ministry of Business, Innovation and Employment (MBIE)Hikina Whakatutuki Lifting to make successful

MBIE develops and delivers policy, services, advice and regulation to support economic growth and theprosperity and wellbeing of New Zealanders.

MBIE combines the former Ministries of Economic Development, Science + Innovation, and the

Departments of Labour, and Building and Housing.

Disclaimer

This document is a guide only. It should not beused as a substitute for legislation or legaladvice. The Ministry of Business, Innovation andEmployment is not responsible for the results ofany actions taken on the basis of information inthis document, or for any errors or omissions.

ISBN 978-0-478-40155-4 (online)ISBN 978-0-478-41302-1 (print)

Published November 2012Reprinted April 2013

Crown Copyright 2013

The material contained in this report is subject to Crown copyright protectionunless otherwise indicated. The Crown copyright protected material may bereproduced free of charge in any format or media without requiring specicpermission. This is subject to the material being reproduced accurately andnot being used in a derogatory manner or in a misleading context. Where thematerial is being published or issued to others, the source and copyrightstatus should be acknowledged. The permission to reproduce Crown copyright

protected material does not extend to any material in this report that isidentied as being the copyright of a third party. Authorisation to reproducesuch material should be obtained from the copyright holders.


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Acknowledgement

The Ministry of Business, Innovation and Employment (MBIE) would like to acknowledgeWorksafe Victoria for the use of content and images from the guidance publicationMachinery and Equipment, An Introduction, July 2007, 1st edition.

The MBIE would like to thank Dulux NZ, Myriad Engineering Ltd and Ferndale FurnitureLtd for allowing us to take photographs in their workplace and use them in this guidanceto illustrate good practice for safe use of machinery.


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Contents Introduction ....................................................................................................... 5

Duty holder responsibilities ................................................................................ 5

Responsibilities in the workplace ....................................................................... 6

1. Identifying machinery hazards ..................................................................... 9

1.1 Mechanical hazards ...................................................................................... 9

1.2 Non-mechanical (other) hazards ................................................................ 10

1.3 Access hazards ........................................................................................... 11

1.4 Control of access hazards ........................................................................... 11

2 Control of machinery hazards ..................................................................... 13

2.1 The hierarchy of controls ............................................................................ 13

2.2 Control of mechanical hazards - isolation ................................................... 16

2.3 Lock out tag out: removing and controlling energy sources during

access ............................................................................................................... 20

2.4 Minimisation - other mechanical hazard risk control options ...................... 23

2.5 Control of non-mechanical hazards............................................................. 26

3 Where to from here .................................................................................... 28

3.1 Ministry of Business, Innovation and Employment call centre .................... 28

3.2 Guidance material....................................................................................... 28

3.3 MBIE publications ....................................................................................... 29

3.4 Worksafe Australia ..................................................................................... 29


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ILLUSTRATIONS

Figure 1 Interlocking gates ................................................................................. 8 Figure 2 Common mechanical hazards and controls .............................................. 9

Figure 3 Extraction systems ..............................................................................10 Figure 4 Using a temporary mobile platform ........................................................12

Figure 5 Centre lathe .......................................................................................14 Figure 6 CNC Lathe ..........................................................................................14 Figure 7 Fences, barriers, guards and interlocked gates ........................................15 Figure 8 Dimensions of barriers .........................................................................17

Figure 9 Fixed guard on a saw ..17

Figure 10 Interlocked guard on refurbished machine ..............................................18

Figure 11 Captive key systems ........................................................................... 19

Figure 12 Examples of tag out and lock out devices ...............................................21 Figure 13 A two-handed control option........... ................ ............. ............. ...........23

Figure 14 Light curtains.....................................................................................24

Figure 15 Use of appropriate personal protective equipment ...................................27


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Introduction

Safe Use of Machinery - An Introduction aims to assist employers and employees tounderstand the hazards associated with the use of machinery in the workplace. It alsogives guidance on how to safely use machinery to comply with the duties and obligationsunder the Health and Safety in Employment Act 1992 ( HSE Act) and the Health andSafety in Employment Regulations 1995 .

Employers can use this guide to:

identify machinery hazards in the workplace eliminate or reduce the likelihood of those hazards causing harm.

Too many serious harm accidents and fatalities occur because employers do not havebasic machine guarding in place. Even though the principles of machine guarding arewell known, people are still being maimed and killed because machines are poorlyguarded.

These guidelines provide advice for anyone interested in machinery safety, includingdesigners, manufacturers, suppliers, employees, and Health and Safety Representatives.

Section 4 in this document details relevant guidance material and standards.

The Safe Use of Machinery project on the Ministry of Business, Innovation andEmployment ( MBIE) website has information and a detailed list of guidance and Ministrypublications about safe use of machinery and machine guarding - www.dol.govt.nz/safe-use-machinery/index.asp.

Duty holder responsibilities

Designing, manufacturing, and supplying machinery

Under Section 18A of the Health and Safety in Employment Act 1992 , a person whohires, leases, sells, or otherwise supplies to another person plant to be used in a place ofwork has specific duties.

People who hire, lease or loan plant must find out whether the plant is to be used in aplace of work and if so its intended use. They must ensure that the machinery and/orplant has been designed, made, and maintained to be safe for its intended use.

People who sell or supply plant that can be used in a place of work must take allpracticable steps to ensure that the plant has been designed and made, and maintained,to be safe for any known intended use or any use of the plant that could be reasonablyexpected.

Similarly, designers, manufacturers, and suppliers of plant and personal protectiveequipment have duties explained in Regulations 66 to 69 of the Health and Safety inEmployment Regulations 1995 .

Health and safety legislation imposes responsibilities on people to ensure the safety ofothers. It also protects users of plant and equipment.

One way that purchasers and hirers of plant and equipment can meet their duties is to

include conditions requiring safe plant or equipment in the purchase contract.
http://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asp


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Examples of conditions in a purchase contract which could promote safety are: Goods shall conform to all relevant New Zealand safety legislation. Goods shall conform with requirements of the following standards: (e.g. AS 4024:

Safety of Machinery (series).

Responsibilities in the workplace

The HSE Act applies to all people at work and others persons in, or in the vicinity of,a place of work. Responsibilities for duty holders are outlined in this section.

The HSE Act creates a number of duties for most people connected with places of work.There are a number of Regulations, Codes of Practice and industry best practice guidancedocuments that support the HSE Act.

The HSE Act and its regulations are the law. Codes of practice, guidelines and otherguidance material published by MBIE are considered best practice.

The employer

Employers are responsible for the health and safety of employees and of any otherpeople who may be affected by the actions or inactions of employees.

An employer is required to take all practicable steps to ensure that work undertaken issafe.

Employers shall have an effective method for identifying hazards to employeesat work and must take all practicable steps to ensure that those hazards are controlled.

Employers shall also take all practicable steps to ensure that employees are adequatelytrained and/or supervised to be able to work safely.

The employee

An employee is defined by the HSE Act as any person of any age who is employed by anemployer to do any work for hire or any reward under a contract of service that is anemployment agreement.

An employee is responsible for their own health and safety and must also ensure thattheir actions or inactions do not harm other people. Employees have a responsibility tofollow the safe work procedures that have been put in place by their employer.

Employees should bring to the attention of their supervisor any illness, ailment or othercondition which may prevent or limit their ability to work with machinery. This isimportant for their safety and the safety of others. It will also assist supervisors withplanning and work allocation.

The self-employed

Self-employed is defined as someone working not as an employee in one or more of thefollowing types of work: providing goods or services for hire or reward under a contractfor services, or carrying on a business as a sole trader, or a partnership.

A self-employed person is responsible for his/her own health and safety and must ensure

that their actions or inactions do not harm other people. A self-employed person is


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responsible for undertaking relevant training and having the capability to safely completetheir work.Person who controls a place of work

In relation to a place of work, a person who controls a place of work means a person whois:

the owner, lessee, sublessee, occupier, or person in possession, of the place orany part of it, or

the owner, lessee, sublessee, or bailee, of any plant in the place.

Employee participation

Involving employees in hazard management is a requirement of the HSE Act. It is also anexcellent process for implementing hazard controls. This can be done by delegatinghealth and safety responsibilities to staff, analysing job safety, holding toolbox meetingsand electing health and safety representatives.

Employee and health and safety representative participation in workplace health and

safety ensures workers are able to provide input and raise potential safety concernsabout their work and workplace. Although hazards associated with machinery can bereadily identified, the ways in which people can gain access to, or may be exposed to,hazards require a detailed understanding of how they do their job. The people who carryout the work generally have a good understanding of how injuries could occur in the workthat they do, e.g. product might back up in the machine and require clearing, and thiscould be hazardous if the machine is still running.

Employers must provide reasonable opportunities for employees to participate effectivelyin on-going processes for the improvement of health and safety in a place of work.Where there are 30 or more employees, or where an employee or union representingemployees requests it, the employer must develop, implement and maintain a system of

employee participation in health and safety.

Where agreement cannot be reached on the system of employee participation, there aredefault provisions set out in the HSE Act in Schedule 1a, Part 3.

Where employee health and safety representatives are elected, they are entitled to paidleave to attend approved training courses.

A trained employee health and safety representative may issue a hazard notice to anemployer where they believe there is a hazard in the place of work, they have brought itto the employers attention and the issue has not been resolved.

Employers and employees must deal with each other in good faith while seekingagreement on, developing and maintaining a system of employee participation.

Principal

A principal is a person or a company that engages any other person or company, otherthan as an employee, to do any work for gain or reward.

A principal to a contract is responsible for the health and safety of employees ofcontractors and subcontractors. This responsibility extends to any contractor orsubcontractor who is a self-employed individual. A principal might also have employeeswho will be owed separate duties because of this employer/employee relationship.


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Putting work out to contract doesnt remove any of the principals health and safetyobligations. Legal responsibilities cannot be transferred to another party.

The legal responsibilities of a principal are set out in Section 18 of the HSE Act.

The steps that should be followed by a principal to ensure good health and safetyoutcomes when work is contracted out are:

scope the work to identify the key health and safety issues before the work is putout to tender or the contract is formalised

pre-qualify the contractor to ensure that they are competent to safely completethe required work

negotiate health and safety requirements when the contractor is selected set out health and safety expectations in the contract documents monitor the contract to ensure that health and safety expectations are met complete a review after the contract and apply lessons to future contracted work.

For further details refer to the MBIE guidance A Principals Guide to Contracting to meetthe Health and Safety in Employment Act 1992 and its summary, Health and Safety in

Contracting Situations.

Fig 1: Interlocking Gates - robotic arms and some other machinery can reach over theirbase, move with remarkable speed and high force, and can cause injury if controls toseparate people from moving plant are not implemented.


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1 Identifying machinery hazards

The key to hazard management is an effective hazard identification process. Hazards canbe identified by:

Physical inspections inspecting the machinery and assessing where someone

could get injured or be caught in the machinery Task analysis identify the hazards involved in each task of the job. This shouldalso include what happens when a blockage occurs or the machine needs cleaningor maintenance

Process analysis identify hazards at each stage of the production process. Analysis of accident investigation identify hazards and causal factors from

investigations involving similar types of work.

In this guidance the hazard types have been divided into mechanical and non-mechanical.

1.1 Mechanical hazards

Trapping Closing nipsbetween platenmotions. In -running nipsbetween pairs ofrevolving parts. In -running nips ofthe belt and pulleytype.

Entanglement Projections onrevolving parts. Revolving drumsand cylinders uncased. Revolving shafts,spindles, mandrels,and bars.

I mpact Automatic guidedvehicles. Moving robot armsand assemblies. Product moving ona conveyor.

Contact Abrasive wheels. Cutting edges ofendless-band cuttingmachines. Reciprocatingknives and saws.

P rojectile Breakage of high -speed cutting tools. Disintegration ofabrasive wheels. Ejection of partswith force.

O ther Hot metal parts. Ionising radiation,such as x-rays. Radiation such asmicrowaves,ultraviolet light, laserbeams and radiowaves.

Fig 2: Common mechanical hazards and associated risks for machinery can be identifiedby use of the mnemonic TIPECO .


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1.3 Access hazards

Operators and employees must be provided with safe access in, on and aroundmachinery. A stable work platform that is suitable to the nature of the work must besupplied. It should allow the operator to maintain good posture relative to the work

performed. It must also provide sure footing, a safe working environment, and fallprevention if working at height.

When thinking about safe access to machinery, think about how, who, when and what: Who will be working on or around the machinery? Are people required to work in enclosed areas where the atmosphere could be

harmful, such as pits, tanks or storage vessels? What equipment or materials need to be carried to undertake the task? Where and when is access required for operation, maintenance and cleaning? How will people gain safe access (walkway, gantry, elevated work platform or

ladder)? What work will be carried out during access? Will people be near or exposed to an unidentified mechanical or non-mechanical

hazard at the time of access? Has consultation occurred with employees or contractors regarding how they

intend to gain access, and what equipment and work platform or structure is bestsuited for the intended task?

1.4 Control of access hazards

Confined space

Larger machinery and equipment may contain enclosed areas that present difficult orrestricted means of access. In confined space oxygen levels may be depleted or displaced

and there may be a build-up of harmful levels of gas, vapour or dust.For further information, refer to the MBIE publication Safe Working in a Confined Space .

Working at height

Providing people with a suitable work platform for the task being undertaken reduces therisk of injury from falling from machinery.

Safe access at height may require use of: fixed or permanently installed access platforms mobile elevating work platforms (MEWPs) temporary platforms.

For further information, refer to MBIEs Best Practice Guidelines for Working at Height inNew Zealand .


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Fig 4: A worker uses a temporary mobile platform to access a machine for cleaning. Theplatform has guardrails on three sides.


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2 Control of machinery hazards

Where exposure to machinery hazards cannot be eliminated or substituted for machineryof improved design, control(s) must be applied to the hazards that prevents or reducesthe likelihood of injury or harm. Sections 7 10 of the HSE Act requires hazards to beeliminated. If elimination is not practicable, hazards should be isolated and if this is notpracticable, hazards are to be minimised.

2.1 The hierarchy of controls

Elimination is changing processes and machinery so operators are no longer exposed tosignificant hazards. This could include replacing noisy machinery with a quieter processor changing the process to get rid of a hazardous machine.

Isolation is preventative and places the hazard out of reach of the operator. These areusually group controls such as fixed guards, interlocked guards or presence sensingsystems.

Minimisation controls, such as personal protective equipment (PPE), can preventinjuries, but is not as effective as isolation, as it relies more on employee behaviour,maintenance programs and supervision.

Minimisation uses systems of work to reduce the potential harm by providing aframework of expected behaviours. Examples are rotation of staff to reduce exposure toa hazard, personal protective equipment, or a documented safe system of work such as

lock out - tag out. These types of controls rely on extensive instruction, information,training and supervision. In terms of time and on-going administration by managers andemployers to ensure the desired behaviour occurs, controls based on minimisation can bemore expensive and the least effective form of hazard control.Minimisation controls can be used in support of isolation controls that deal with a hazardat its source and should not be considered as the sole means of control. Minimisationrequires constant monitoring and reinforcement.

Hazard management should consider the operations of people: who installs or dismantles machines who operate machines and equipment who provide maintenance or repair services who provide cleaning services.


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Fig 5: A centre lathe can cause serious injury and death through ejecting parts or toolswith great force.

Fig 6: Replacing a centre lathe with a CNC lathe (Computer Numeric Control)dramatically reduces the risk of injury by isolating the dangerous parts from theoperator.


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Figure 7: Fences, barriers, guards and interlocked gates separate people from thehazardous action of machinery.


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2.2 Control of mechanical hazards isolation

Isolation is a simple and effective method of controlling hazards of machinery. Isolationmeans a persons reach into machinery is limited by barriers achieved by distance,barrier or time.

Distance separation means a person cannot reach the hazard due to distance.Barrier separation means an effective barrier or guard denies access and controlsejection of parts, products or waste.Time separation means at the time of access, the machinery is disabled.

Workers ability to reach into a machine upwards, over, around, along or into machineryneeds to be taken into account when developing hazard controls. The potential to reacharound barriers into the hazardous area can be limited by design factors including theheight, distance and depth of barriers.

Reach is limited by the arms, and, in the case of openings, by fingers and hands also.Less often, hazards may be reached by a lower limb. The distance a person can reachdetermines the minimum height of certain kinds of guards, or the minimum distance ofbarriers from the machines they are intended to fence. For more detail see MBIEpublication The Ergonomics of Machine Guarding and also AS 4024.1802: Safety distancesto prevent danger zones being reached by the upper limbs and AS 4024.1802: Safetydistances and safety gaps - Safety distances to prevent danger zones being reached by thelower limb.

Examples of means of isolation include: physical barriers and guards such as fences, screens or fixed panels of various

materials various forms of guarding and interlocking. Refer to the Australian standard AS

4024, Safety of Machinery, part 1601: Design of controls, interlocks and guarding Guards General requirements for the design of fixed and movable guards and part1602: Interlocking devices associated with guards- Principles for design andselection.

making the hazard inaccessible by reach (where the distance between a personand the hazard forms an effective barrier).

When considering the suitability of distance guarding, also consider the safe accessrequirements of maintenance people who need to gain access by ladder, scaffold orelevated work platform.

While machinery overhead may be out of reach from the floor, hazard assessment mustconsider the possibility that people will stand on ladders, furniture, or parts of machines,

and reach into danger. Therefore it is not practicable to provide a height which willensure a hazard is safe by position. Hazard management must take into account themeans by which a person can raise themselves above floor level, so that machinerynormally out of reach can be reached.


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Fig 8: A barrier should be high enough to prevent reach over to the hazard, haveopenings too small to allow reach into the hazardous area. Barriers may allow an openingunderneath big enough for a broom but too small for a person to reach under into thehazardous area .

Guarding

A guard can perform several functions: it can deny bodily access, contain ejected parts,tools, off-cuts or swarf, prevent emissions escaping or form part of a safe workingplatform.

Where access is not anticipated, a fixed guard can be permanently applied by bonding

agent, welding or secured with one-way screws. If access is generally not required, apermanently fixed barrier is the preferred option.

Where access to the hazard is infrequent, the installation of a fixed guard that can beremoved by use of a tool may be an acceptable control, where the tool to remove thebarrier or guard is not normally available to the operator.

Fig 9: The guard on the saw protects the operator from the exposed blade.


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Fig 10: Hazardous moving parts on an older style press are isolated with a removablefixed guard.

Tunnel guards provide a tunnel, aperture or chute in which material can be insertedinto the machinery, but due to the restrictive design and depth of the opening, fingers,hands, arms or the entire person is prevented from intruding into the danger area.

Where frequent cleaning is required, the guard may be constructed of mesh thatprevents intrusion of body parts but allows for hosing. Food production workplaces thatuse conveyors in areas where hygiene or food safety is an integral part of the operationshould use fixed mesh guarding of conveyor end rollers.

Interlocked guarding works when the act of moving the guard (opening, sliding orremoving) to allow access stops the action of the hazardous mechanism.

Interlock guarding works by: mechanically disconnecting the drive mechanism (applies a brake or disengages a

clutch or geared mechanism) isolating the power source of the drive mechanism (stops the motor) a combination of mechanical and power disconnection.

Interlocked guarding is generally achieved via mechanical or electrical means, but mayalso include hydraulic or pneumatic control systems.

The energy stored in moving parts (momentum) can cause the mechanism of themachine to run on for some time after the source of driving energy has been removed.

For access panels or doors supporting an interlocking device that allows access tomechanical parts that move for periods after the energy source is removed, a separatemechanism to delay release of the retaining or locking mechanism may be incorporated.

If the dangerous part of a machine is accessible, the interlock shall prevent the machinefrom starting. If access to the dangerous part is required while the machine is running,the interlock shall stop the machine before the dangerous part is accessible.


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Power operated guards are used where one operation closes the guard and initiates,for example, the power stroke of a press. Guards must enclose the dangerous part of amachine before the power stroke begins. Guards should operate with the minimum offorce to prevent the guard from causing a trapping hazard. If guard closure is stopped,by the presence of an arm for example, the power stroke will not start.

Captive or trapped key systems rely upon a single key that is shared between thecontrol panel (on switch) and the access gate lock of the physical barrier to the dangerarea. Removal of the key from the control panel can only occur when the switch is in theoff position, and the gate will only release the key when in the locked position.

Captive key systems do not provide full isolation of the power source, but may providelimited temporary access under controlled conditions.

Effective supervision, instruction and training are required as administrative controls toensure that only one key is available for the system, and the key is not removed fromthe access gate or guard by a second operator while a person is exposed to the danger

area of the machine. Operations such as maintenance, repair, installation service orcleaning may require all energy sources to be isolated and locked out to avoid accidentalstart-up.

Fig 11: Captive key systems: The key cannot be removed unless it is in the off position.The same key is used to unlock the access gate. Only one key per system is retained bythe locking mechanism.


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2.3 Lock out tag out: Removing and controlling energy sourcesduring access

People performing tasks such as maintenance, repair, installation, service, and cleaningare highly vulnerable, and have a higher risk of being killed or injured through

inadvertent operation of machinery they are working in, on or around.

Accidental start-up or movement of a machine mechanism can occur if control levers orbuttons are bumped or knocked, if a short circuit of the control system occurs, whenhydraulic or air pressure is released, or when undoing retaining bolts.

It is essential that people who work in, on or around machinery are not exposed tohazards due to accidental start-up or movement of the mechanism.

The following is an overview of the lock out tag out process: shut-down the machinery identify all energy sources and other hazards

identify all isolation points isolate all energy sources de-energise all stored energies lock out all isolation points lock out tag machinery controls, energy sources and other hazards test by trying to reactivate the plant without exposing the tester or others at risk failure to reactivate ensures that isolation procedures are effective and all

stored energies have been dissipated.

For more information refer to Australian Standard AS 4024.1603 Design of controls,interlocks and guards - Prevention of unexpected start-up .

Identifying energy sources

Energy sources for ignition should be identified. Energy sources include: electricity(mains); battery or capacitor banks; fuels; heat; steam; fluids or gases under pressure(water, air steam or hydraulic oil); stored energy; gravity; radiation.

If original designer and installer as built diagrams of machinery installations are notavailable, new diagrams and photographs showing location and details of variousisolation points of machinery should be developed as part of the isolation procedures.Isolation points may include switches, valves, energy lines, pipes, power sources.

These diagrams and photographs can then be used, along with written procedures, forinformation and training.

De-energise stored energies

The lockout system must ensure all energy in the system is discharged and themachinery cannot reignite or continue moving.

Any or all of the following steps are necessary to guard against energy left in themachinery after it has been isolated from its energy sources:

inspect the machinery to make sure all parts have stopped moving install ground wires release the tension on springs or block the movement of spring-loaded parts block or brace parts that could fall block parts in hydraulic and pneumatic systems that could move from pressure

loss


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bleed the lines and leave vent valves open drain process piping systems and close valves to prevent the flow of hazardous

material if a line must be blocked where there is no valve, use a blank flange purge reactor tanks and process lines dissipate extreme cold or heat, or provide protective clothing if stored energy can accumulate, it must be monitored to ensure it stays below

hazardous levels.

Isolation procedures

Isolation procedures in each workplace vary in detail because of differences inmachinery, power sources, hazards and processes.

Activating operational stop buttons, emergency stop devices or interlock devices is notequivalent to the isolation of power sources or the release of stored energy.

Working on energized equipment

Sometimes machinery needs energy for a specific task for example when making fineadjustments or troubleshooting and a part of the machine needs to keep working. Inthese cases energy should only be supplied to parts that are vital to the maintenanceprocess.

How to minimise the risks

Work on energised machinery must only be carried out by workers who are: qualified to do the work authorised by the employer to do the work provided with and follow written safe work procedures, for example, permit to

work. This may also include extra supervision.

Isolation devices for lock out

A wide range of devices is available for locking out energy sources and other hazardsthat could pose a risk to people working on machinery.

Tag and lock. Multiple locks. Valve lock and tag.

Fig 12: Examples of tag out and lock out devices.

For further information, refer to MBIE documents: Guidance Notes for Electrical Interlocking for Safety in Industrial Processes Guide to health and safety in the timber processing industry.


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One person one lock

If more than one person is working on the same item of machinery, each person shouldattach their own lock to prevent the isolator being opened while their specific task is inprogress.

One lock one key

Each person working on the machinery should have their own lock, key and tag. Thereshould be no duplicate key available for any lock, except a master or duplicate key foruse in an emergency that is secured and not readily available.

Multiple energy sources

If more than one energy source or hazard has to be locked out to enable safe shut-downof the machinery, the single key to each lock out device should be held by the sameperson.

Tag out

A tag on its own is not an effective isolation device. A tag should only be attached to themachinery once the operator (or whoever) has locked out the energy source.

How to release machines safely from lockout

Before releasing a machine to production operations, the staff who put in place thelockout must follow these steps:

1. Remove all non-essential items (for example tools, spare parts etc.).2. See that all equipment parts are in the correct place for the machinery to operate,

including guards and safety devices.

3. Inspect for obstructions, incomplete work, etc. Where necessary carry out a teaminspection using trained workers to check specifics, for example hydraulics,pneumatics.

4. Repair or replace safeguards or safety devices before removing lockouts.5. Remove each lockout device using the correct removal steps.6. See that everyone is physically clear of the machinery before energy is switched

back on.7. Develop and follow a special lockout procedure where staff are not available to

clear their personal locks because of sickness, absenteeism, etc.


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2.4 Minimisation - other mechanical hazard risk control options

Simultaneous two-handed operation

A two handed control system ensures the safety of the operator, but will not protect

others near the machine so would only be acceptable where it can be shown that is notpracticable to use other safe guarding methods.

Where a machine has only one operator, the use of simultaneous two-handed operationbuttons can serve as a hazard control. This ensures that operation of the hazardousmechanism cannot occur until both hands are clear of the danger area.

The two buttons must be pushed at the same time and are located at a distance fromeach other that prevents simultaneous operation by one hand or arm.

The controls should also be a hold-to-run type so that on release of hand or arm pressureto one control the dangerous motion of the machine will stop immediately.

Fig 13: A two-handed control option may be suitable to ensure that a machine cannotoperate until both hands of the operator are clear of the hazard area .

Presence sensing systems

If physical guards are not reasonably practicable, then a presence sensing system can be

used as a control to isolate hazards.

Presence sensing systems are capable of providing a high degree of flexibility with regardto access.

Presence sensing systems detect when a person or object is in the identified danger area,and stops or reduces the power or speed of the mechanism at the time of entry toprovide for safe access.

Presence sensing systems can rely on foot pressure pads, infra-red sensing, light beamsor laser scanning. The most appropriate type of sensing device will depend on theoperating environment and access requirements.


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Electro-sensitive Safety Systems - Electronic Systems for Machine Operator Safety and IEC61496 Safety of machinery - Electro-sensitive protective equipment provide guidance ondesign specification, rat ings on integrity and reaction times. Manufacturers specificationsfor installation and maintenance must also be observed.

Specialist assistance may be required by experienced professionals to ensure correctselection and installation of presence sensing systems. Companies who manufacture orsupply these systems also provide technical support and installation assistance.

Fig 14: A light curtain used to disable the hazardous mechanism of a machine mustresist failure and fault. Components relied on to protect people from harm are designedand built to a high standard, and display compliance ratings relative to their reliability.They must also be correctly installed and maintained to ensure their effective operation.

Trip guards can be used where other guarding methods are not practical. They work onsimilar principles as that of a pressure sensitive mat or operate by limit switches. A tripguard is arranged so that if a person reaches close to a dangerous part of a machine, thetrip guard will be activated, which in turn will cause the hazard presented by the machineto cease.

When a trip guard operates, an impulse from the detector or limit switch will cause, via asuitable interface, an emergency stop of the machine and shut down of its power source.

If this system fails, there is no substantial physical barrier to stop people from cominginto contact with the dangerous parts. All safety trip guards should be regularly tested,and hard wired to directly activate the machine control and power brake systems.

Adjustable guarding incorporates movable sections or panels of the guard and allowsfor material or parts to be fed into the guarded area while still preventing bodily contact.Safety relies on correct adjustment of movable guards to restrict access.


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Critical safety systems

A safety control system responsible for ensuring the safety of a person when approachingor accessing a hazard is called a critical safety system.

Failure of the critical safety system will leave a person exposed to the hazard, and indanger.

Critical safety systems may include barriers or guards fitted to prevent access, orintegrated complex interlocking and presence sensing systems. Failure to replace guards,damaged perimeter fences that allow access and bypassed or disabled interlockingsystems are examples of critical safety systems failures that require immediate attentionto ensure the safety of people.

High integrity/fail-safe control

All safety control systems should be designed and built to prevent failure or, in the eventof failure, de-activate the operation of the machinery.

The extent to which a safety control system should tolerate faults is a function of risk(likelihood and consequence), and is described in Australian Standard AS 4024.1501Safety Related Parts of Control Systems , which explains the categories of controlrequired as a function of increasing risk.

Many different types of machinery use high integrity safety systems that disable amechanism at the time of access. Some examples include:

brake press power press robotic machine (automated machines)

injection moulders powered guillotines programmable lathe and milling equipment industrial mixers mincing equipment plasma cutting tables laser cutting tables.

Redundant and self-monitoring fault detection systems

Redundant or dual systems (doubling up) and self-monitoring fault detection systems arealso effective methods to prevent failure of critical safety systems.

Selection and installation of these types of complex interactive control measures mayrequire expert or specialist assistance.

More information on plant safety systems and the current state of knowledge and bestpractice is available in the AS 4024 Safety of Machinery series of publications.


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2.5 Control of non-mechanical hazards

Isolation

The first step in selecting suitable and effective controls for non-mechanical hazards is tounderstand the nature of emissions that can be released by machinery in the workplace,where those emissions collect and the way they may cause harm.

Non-mechanical hazards such as fumes and dust, should be controlled at their sourceand either eliminated or isolated from the workplace.

Hoods, lids, covers or impervious guards (solid barriers that prevent escape of theemission) can serve to contain a number of different types of emissions withinmachinery.

For noise, guarding may also serve to mute noise emissions through application of soundabsorbing materials. Other emissions such as lasers, ultra-violet light, bright light orwelding flash can also be safely screened to prevent potential harmful exposure.

Oil leaks from machinery may present a serious slip hazard. By preventing oil leaksthrough routine maintenance, or containing leaking oil with a drip tray or through spillcontainment strategies, the risk the hazard presents is controlled.

Minimisation

For potentially harmful substance exposures from machinery, such as mist, fumes,vapour or dust, and where it is not reasonably practicable to control the emission at itssource, ventilation and extraction systems are used to remove the hazardousatmosphere from the work environment.

Personal protective equipment

Where it is not reasonably practicable for emissions to be controlled at their source orremoved or reduced through effective ventilation, extraction or diversion, the use ofpersonal protective equipment (PPE) as a final measure must be considered to ensuresafety.

PPE is a minimisation control and can only be used where higher order controls are notreasonably practicable or are not totally effective.

Selection and use of PPE requires careful consideration, as there are many different typesthat reduce the risk of injury of contact or exposure to a hazard.

Incorrect use of PPE or purchasing inappropriate PPE can contribute to serious workplaceincidents. PPE that is uncomfortable, restrictive or heavy may create secondary hazards,and, as a result, constant supervision may be necessary to ensure it is used effectively.

For further information, refer to MBIE guidance Getting staff to wear safety gear ;www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asp .

Wearing personal protective equipment is a minimisation strategy. The Health and Safetyin Employment Act 1992 Section 10 requires that the employer monitor the employeesexposure to the hazard; and with their informed consent, to monitor the employees

health in relation to exposure to the hazard.
http://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asp


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Employers must ensure that their employees have sufficient knowledge and experienceto use of any protective clothing or equipment. The training must be given to theoperators in a manner that they are likely to understand, especially for staff with Englishas a second language.

Specific training requirements should normally be detailed in the manufacturersinstruction handbook.

Fig 15: Use the most effective personal protective equipment for the task.

Training

Depending upon both the type of workplace and the user's previous experience, trainingmay take many forms including: on-the-job training, structured in-house training orattending a manufacturers or suppliers training course.

Training course designers should take into account language and cultural considerations,using active training methods. To ensure the success of training, employers should verifyany new employees experience or knowledge through sighting their training certificatesand observing their work methods.


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3 Where to from here

Employees can contact their union. Employers can contact their industry association. Ministry of Business, Innovation and Employment publications can be obtained by

phoning Ministry of Business, Innovation and Employment on toll free 0800 20 9020. If calling from overseas call +64 9 969 2950. If you know the name of the person you wish to contact, you can email them at:

[email protected]. Visit www.osh.govt.nz/index.asp .

3.1 Ministry of Business, Innovation and Employment call centre

The Ministry of Business, Innovation and Employment provides a free advisory service forhealth and safety issues in workplaces. Although specific information for some complexproblems cannot always be provided over the phone, advisory staff can forward yourquery or tell you who to contact or where to go for specific guidance and information.

For access to free publications and advice or to report an unsafe workplace, call toll-free0800 20 90 20 during normal business hours, 8.30am - 5.00pm Monday to Friday.

3.2 Guidance material

New Zealand Legislation

Health and Safety in Employment Act 1992 Health and Safety in Employment Regulations 1995

For copies of the above Acts and Regulations, go to www.legislation.govt.nz/default.aspx .

Technical Standards

Standards New Zealand www.standards.co.nz/default.htm

Australian Standards (available from www.saiglobal.com )

AS 4024: Safety of Machinery (series) AS 1755: Safety of Conveyors

European Standards IEC 61496: Safety of machinery - Electro-sensitive protective equipment

EN ISO 13849-1 Safety-Related Parts of Control Systems
http://www.osh.govt.nz/index.asphttp://www.osh.govt.nz/index.asphttp://www.osh.govt.nz/index.asphttp://www.legislation.govt.nz/default.aspxhttp://www.legislation.govt.nz/default.aspxhttp://www.legislation.govt.nz/default.aspxhttp://www.standards.co.nz/default.htmhttp://www.standards.co.nz/default.htmhttp://www.standards.co.nz/default.htmhttp://www.saiglobal.com/http://www.saiglobal.com/http://www.saiglobal.com/http://www.saiglobal.com/http://www.standards.co.nz/default.htmhttp://www.legislation.govt.nz/default.aspxhttp://www.osh.govt.nz/index.asp


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3.3 MBIE publications

The Safe Use of Machinery project on the MBIE website has detailed information and adetailed list of guidance and Ministry publications about safe use of machinery andmachine guarding. www.dol.govt.nz/safe-use-machinery/index.asp

Safe Working in a Confined Space, 2001.www.osh.govt.nz/order/catalogue/34.shtml

A Principals Guide to Contracting to Meet the Health and Safety in Employment Act 1992, 2010.www.osh.govt.nz/order/catalogue/contracting-guide.shtml

Health and Safety in Contracting Situations, 2010.www.osh.govt.nz/order/catalogue/contracting-health-safety.asp

Guidance Notes for Electrical Interlocking for Safety in Industrial Processes, 1994*www.osh.govt.nz/order/catalogue/350.shtml

Electro-sensitive Safety Systems - Electronic Systems for Machine OperatorSafety, 2000*.www.osh.govt.nz/order/catalogue/presencesensingdevices.shtml

The Ergonomics of Machine Guarding, 1979*.www.osh.govt.nz/order/catalogue/795.shtml

Getting Staff to Wear Safety Gearwww.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asp

Guidelines for Guarding Principles and General Safety for Machinery to Meet theRequirements of the Health and Safety in Employment Act 1992 and itsRegulations 1995*.www.osh.govt.nz/order/catalogue/66.shtml

Approved Code of Practice for Power-Operated Elevating Work Platforms, 2003*.www.osh.govt.nz/order/catalogue/195.shtml

Guide to Health and Safety in the Timber Processing Industry, May 2005.www.osh.govt.nz/order/catalogue/timberprocess.shtml

Best Practice Guidelines for Working at Height in New Zealand, 2012.www.osh.govt.nz/publications/booklets/working-height/index.asp

Further information about machine guarding and safe use of machinery can be found onthe MBIE Safe Use of Machinery webpage www.dol.govt.nz/safe-use-machinery/index.asp .

* This publication is under review .

3.4 Worksafe Australia

Worksafe Australia - www.worksafe.vic.gov.au

Machinery and Equipment, An Introduction, July 2007, 1st edition.

www.worksafe.vic.gov.au/forms-and-publications/forms-and- publications/machinery-and-equipment-safety-an-introduction
http://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.osh.govt.nz/order/catalogue/34.shtmlhttp://www.osh.govt.nz/order/catalogue/34.shtmlhttp://www.osh.govt.nz/order/catalogue/contracting-guide.shtmlhttp://www.osh.govt.nz/order/catalogue/contracting-guide.shtmlhttp://www.osh.govt.nz/order/catalogue/contracting-health-safety.asphttp://www.osh.govt.nz/order/catalogue/contracting-health-safety.asphttp://www.osh.govt.nz/order/catalogue/350.shtmlhttp://www.osh.govt.nz/order/catalogue/350.shtmlhttp://www.osh.govt.nz/order/catalogue/presencesensingdevices.shtmlhttp://www.osh.govt.nz/order/catalogue/presencesensingdevices.shtmlhttp://www.osh.govt.nz/order/catalogue/795.shtmlhttp://www.osh.govt.nz/order/catalogue/795.shtmlhttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.osh.govt.nz/order/catalogue/66.shtmlhttp://www.osh.govt.nz/order/catalogue/66.shtmlhttp://www.osh.govt.nz/order/catalogue/195.shtmlhttp://www.osh.govt.nz/order/catalogue/195.shtmlhttp://www.osh.govt.nz/order/catalogue/timberprocess.shtmlhttp://www.osh.govt.nz/order/catalogue/timberprocess.shtmlhttp://www.osh.govt.nz/publications/booklets/working-height/index.asphttp://www.osh.govt.nz/publications/booklets/working-height/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.worksafe.vic.gov.au/http://www.worksafe.vic.gov.au/http://www.worksafe.vic.gov.au/http://www.worksafe.vic.gov.au/forms-and-publications/forms-and-publications/machinery-and-equipment-safety-an-introductionhttp://www.worksafe.vic.gov.au/forms-and-publications/forms-and-publications/machinery-and-equipment-safety-an-introductionhttp://www.worksafe.vic.gov.au/forms-and-publications/forms-and-publications/machinery-and-equipment-safety-an-introductionhttp://www.worksafe.vic.gov.au/forms-and-publications/forms-and-publications/machinery-and-equipment-safety-an-introductionhttp://www.worksafe.vic.gov.au/forms-and-publications/forms-and-publications/machinery-and-equipment-safety-an-introductionhttp://www.worksafe.vic.gov.au/http://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.dol.govt.nz/safe-use-machinery/index.asphttp://www.osh.govt.nz/publications/booklets/working-height/index.asphttp://www.osh.govt.nz/order/catalogue/timberprocess.shtmlhttp://www.osh.govt.nz/order/catalogue/195.shtmlhttp://www.osh.govt.nz/order/catalogue/66.shtmlhttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.dol.govt.nz/infozone/businessessentials/safety/hazards/getting-staff-to-wear-safety-gear.asphttp://www.osh.govt.nz/order/catalogue/795.shtmlhttp://www.osh.govt.nz/order/catalogue/presencesensingdevices.shtmlhttp://www.osh.govt.nz/order/catalogue/350.shtmlhttp://www.osh.govt.nz/order/catalogue/contracting-health-safety.asphttp://www.osh.govt.nz/order/catalogue/contracting-guide.shtmlhttp://www.osh.govt.nz/order/catalogue/34.shtmlhttp://www.dol.govt.nz/safe-use-machinery/index.asp


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