WMC has developed this document for internal use, specific to circumstances and conditions within its operations. It is intended to provide general information and its applicability to external parties may therefore be limited. WMC makes no
representations as to the applicability of the information for use by any party other than WMC and should not be relied upon as such. WMC provides no representation or warranty as to safety or business outcomes arising from application
of this document and its requirements by third parties.
Angle Grinders Standard
WMC-EHS-STD-012A.4 Owner: Peter Plavina Champion: Jeff Landels DocsOpen Ref: 152567
Uncontrolled copy – check web for latest revision
Revision Reviewed Description of Changes Date Approved
1 D Batchler Updated to include inspection requirements 16/07/2004 M Webb
2.1 Summary of Potential Hazards in the Use of Portable Angle Grinders .............................. 4 2.2 Hazard Control Measures................................................................................................... 5
3 ACCOUNTABILITIES AND RESPONSIBILITIES.................................................................... 10 3.1 Site General Manager ...................................................................................................... 10 3.2 Supervisors....................................................................................................................... 10 3.3 Personnel Using Angle Grinders ...................................................................................... 10
Summary of Data from Incidents Involving Angle Grinders......................................................... 13 Generic Procedure for Changing a Disc on an Angle Grinder .................................................... 14 Summary of Angle Grinder Hazards and Safe Operation Rules ................................................. 17 Template for a Site Approval Form for ‘Use of Cutting Discs > 127mm’ ..................................... 21 Summary of General Restrictions on the Use of Portable Angle Grinders.................................. 22 Assessment for Users of Angle Grinders .................................................................................... 24
This Standard describes the potential hazards associated with the use of portable angle grinders and sets down the requirements and control measures for the safe and efficient use of these tools. Clearly, many of the hazards and control measures relating to portable angle grinders also apply to bench grinders and must be applied accordingly.
These requirements and control measures are applicable throughout the WMC business.
1.1 Overview
Portable angle grinders are lightweight, hand held machine tools. They can be powered either electrically or pneumatically.
Portable angle grinders are typically used in WMC workplaces to: grind excess metal from welds remove rust do a range of metal cutting activities; and do special finishing / polishing operations.
An analysis of the potential hazards and a review of workplace injury and incident data shows that portable angle grinders require special precautions to be taken if they are to be operated safely and effectively. Since this tool is hand held, safe operation and the quality of work is also dependent upon the user’s skill and experience.
This Standard has requirements for hazard controls covering the following topics: Tool selection and maintenance General Restrictions on angle grinder use Pneumatic and electrical tool safety Training and awareness Angle grinder ‘safe operation rules’; and Personal Protective Equipment.
This document also includes (in the Appendices) a generic procedure for changing a disc on an angle grinder, a ‘Summary of Angle Grinder Hazards and Safe Operation Rules’ that can be distributed in
the workplace, and the Approval Form for ‘Use of Cutting Discs > 127mm’ (5”).
2.1 Summary of Potential Hazards in the Use of Portable Angle Grinders
A review of incidents involving the use of portable angle grinders shows that the primary hazards arising from the use of portable angle grinders are: Electrical (electric shock to operator) Sparks / hot metal (burns / fires) Contact with rotating disc / wheel (cuts) Being struck by flying objects (including dust into eyes) Disc / wheel shattering /‘exploding’ (severe injury including permanent disability or death).
Data to support this assessment is provided in Appendix A of this Standard.
In addition to the hazards identified above, the following potential hazards must also be recognised: Vibration related disorders (numb fingers, ‘white finger’ / Raynaud’s syndrome) Cuts to, or blows received by, nearby people (other than the operator of the angle grinder)
as a result of material be ejected by the angle grinder Noise induced hearing loss Hair or clothing caught in rotating parts of the equipment, and Sprain or strain from lifting or holding the angle grinder incorrectly.
The following can be Contributing Factors to the hazards listed above: Operating an angle grinder without a correctly fitted and positioned guard, Object being cut / ground not properly secured or positioned, Inadequate, poorly positioned or poorly maintained handles on the angle grinder, Operator fatigue from prolonged use of an angle grinder (holding , supporting, applying
pressure), Use of angle grinders in awkward or unbalanced positions e.g. overhead, in a confined
space, arms or body extended, Inadequate selection and/or use of Personal Protective Equipment, Lack of skill and/or competency of operator in use of angle grinder, Angle grinder discs or wheels shattering / ‘exploding’ as a result of the following:
- use of the wrong disc or wheel for the job e.g. cutting disc used for grinding, or an inappropriate operating speed chosen for the disc or wheel in use,
- disc / wheel not properly installed, - disc / wheel not properly maintained or not replaced when worn / glazed, - disc ‘jamming’ during a cutting job, - allowing the wheel to rest on one spot for too long (overheating), - moisture being absorbed into (part of) a disc causing it to be ‘unbalanced’, or
- material embedded in a disc / wheel from a previous job reacting with material (and heat) generated in the current job e.g. aluminium grinding followed by steel grinding.
Electric shocks can result from either: - Disc cutting through the electrical supply cable, or - Poor quality or poorly maintained equipment or cables.
2.2 Hazard Control Measures
When determining the appropriate range of controls to be applied to a particular angle grinding task, the Hierarchy of Controls must be actively applied i.e.
1. Elimination / substitution
2. Engineering / physical controls
3. Administrative /procedural controls
4. Personal Protective Equipment
Before undertaking any task where an angle grinder may be used, every person involved in the job must also apply the principles of ‘Take Time, Take Charge’:
Stop…before you start the job
think…about the hazards
assess…the job and the workplace
respond…make the right decision
The third general principle to apply when determining appropriate controls is ‘Change Management’. Before commencing a task the following must be considered: changes to the work environment e.g. since the last time the task was done changes to the work procedure or practice changes to the equipment to be used, and changes to the people involved e.g. new and/or inexperienced operators.
The requirements in the following sections of the Standard must be met when applying the Hierarchy of Controls, ‘Take Time, Take Charge’ and Change Management principles.
2.2.1 Tool Selection and Maintenance
The following general considerations must be made before commencing a task that may involve the use of an angle grinder: Question whether an angle grinder is the most appropriate tool for the job. Based on the
review of incident data, this question must be most strongly applied to any planned task that involves the angle grinder being used for cutting.
If an angle grinder is appropriate for the job, then the following must be considered: Angle grinders can be powered electrically or pneumatically. Determine which type is best
for the job (see Section 2.2.3), Some (typically pneumatic) angle grinders have a brake that stops the disc when the trigger
is released while others allow the disc to spin and slow to a stop. While disc brakes can improve safety in some situations, the inertia they impart when they activate can introduce other hazards,
There is a huge variety of discs and wheels that can be utilised. Ensure that the type chosen is appropriate for the job. If the required disc or wheel is not available, do not improvise – delay the task until the correct disc or wheel is obtained or find an alternative means of doing it. In particular: - Never use a grinding wheel for cutting (or vice versa), - Ensure that that the disc or wheel is appropriate for the material being cut or ground
e.g. metal or masonry, and - Ensure that the size of the disc or wheel is matched to the operating speed of the
angle grinder and to the task. The biggest available disc or wheel may not be the best option.
Both the angle grinder and the disc or wheel need to be regularly inspected and maintained. In particular, ensure that that the disc or wheel is not chipped, cracked, glazed or damaged in any way that could cause it to shatter or ‘explode’.
2.2.2 General Restrictions On the Use of Portable Angle Grinders
In addition to the specific restrictions on the use of angle grinders that may come out of a Task Hazard Analysis or site Safe Work Procedure, the following general restrictions apply across WMC: Non ‘Trades or Metal Trades’ personnel may, after meeting the requirements of this
Standard, only use angle grinders fitted with grinding discs where the disc is not greater than 127mm (5”) in diameter,
Non ‘Trades or Metal Trades’ personnel are not permitted to use angle grinders with cutting discs,
‘Trades’ personnel may, after meeting the requirements of this Standard, use angle grinders fitted with either grinding or cutting discs where the disc is not greater than 127mm (5”) in diameter
Metals Trades’ personnel may, after meeting the requirements of this Standard, use angle grinders fitted with grinding discs where the disc is not greater than 180mm (7”) in diameter,
‘Metals Trades’ personnel who need to use an angle grinder with a cutting disc of > 127mm (5”) can only do so after completing, and having approved by their line supervisor, the form included as ‘Appendix D’ to this Standard. This form will not be approved until a formal Task Hazard Analysis (THA) has been completed or a Safe Work Procedure is produced,
The use of an angle grinder with either a grinding wheel or a cutting disc > 180mm (7”) is only permitted with specific approval on a ‘job-by-job’ basis of the work area supervisor. If a cutting disc is to be used, the form in Appendix D must be completed as above,
Any angle grinder that is to be used with either a wheel or disc >127mm (5”) must be fitted with a functional ‘deadman’ switch. A ‘deadman’ switch is, however, recommended for all angle grinders,
All angle grinders must be fitted with handles that meet the manufacturer’s specifications. This restriction can be revoked for an angle grinder that is to be used with a grinding wheel <127mm (5”) for a task where a formal Task Hazard Analysis has been completed and there is specific approval on a ‘job-by-job’ basis by the work area supervisor,
All angle grinders must be fitted with ‘correctly fitted and positioned’ guards that meet the manufacturer’s specifications. This restriction can only be revoked after completion of a formal Task Hazard Analysis and with specific approval on a ‘job-by-job’ basis of the work area supervisor,
Angle grinders must not have an active override (a ‘lock on’) switch, The use of cutting discs fitted with tungsten tips is only permitted with specific approval on a
‘job-by-job’ basis of the work area supervisor, and It is recommended but not mandatory that angle grinders be fitted with anti-kickback
devices. This includes electric grinders fitted with a clutch that disengages the disc if it becomes jammed, and compressed air grinders that stall rather than kick back.
For the purposes of this Standard, ‘Metal Trades’ personnel are those people who have completed an apprenticeship and been awarded a Trades Certificate in a Metals Trade e.g. Boilermaker, Fitting & Machining.
‘Trades’ personnel are those people who have completed an apprenticeship and been awarded a recognised trades Certificate.
These General Restrictions are summarised in a table in Appendix E of this Standard.
2.2.3 General Pneumatic and Electrical Tool Safety Requirements
The following general safety requirements must be observed when operating pneumatic and electrically powered angle grinders: Never use electrical grinders in wet or damp conditions, Electrical tools must be connected through a residual current (earth leakage) device, Do not use electrical tools near flammable liquids or gases, Inspect all electrical cables, pneumatic hose lines and connections prior to use, Ensure that the air pressure supply is, and remains, within the specified operating limits, Regularly inspect and maintain electrical and pneumatic tools to keep them in proper
working order, Ensure that any powered hand tools are used in accordance with the manufacturer’s
instructions, and Always wear the specified Personal Protective Equipment while operating powered hand
It is an important part of a Supervisor’s General Accountabilities under this Standard (Section 3) to ensure that people under their control who are to use angle grinders “have the appropriate tools, equipment, licences, skills, induction and training to safely undertake their tasks”
In most circumstances (see Section 2.2.2) the required skills will be held by ‘Metal Trades’ personnel. For the purposes of this Standard, ‘Metal Trades’ personnel are those people who have completed an apprenticeship and been awarded a Trades Certificate in a Metals Trade e.g. Boilermaker, Fitting & Machining.
Where a Supervisor chooses to use a Non ‘Metals Trade’ person to use an angle grinder, they must satisfy themselves that this person has received appropriate training and is able to complete the task safely.
For all personnel using angle grinders, their Supervisor must periodically reassess their ability to complete such tasks safely.
Some guidance on assessing ability is provided in Appendix F to this Standard.
2.2.5 Angle Grinder ‘Safe Operation Rules’
Check your equipment before use including: Inspect the angle grinder to ensure that the chassis is intact i.e. no cracks or parts loose, Inspect the body of the grinder and the grinder electrics to ensure there is no build up of
conductive dust (such as carbon) from previous use that could cause the motor to arc. Inspect the disc and disc guard. Make sure that they are in place and secure. Ensure that that the disc or wheel is not chipped, cracked, glazed or damaged in any way
that could cause it to shatter or ‘explode’, Check the handle(s) to ensure that they are secure and not damaged, Check to see that the test tag on the power cord is up-to-date and that the ‘on-off’ and/or
‘deadman’ switch is in good working order, and Conduct a ‘test start’ to check the angle grinder for balance and vibration. If unusual and/or
excessive vibration is encountered during the test or at any time during use, immediately stop work , unplug the unit, remove the disc and inspect it and the angle grinder for damage or incorrect mounting. If you are unable to locate and correct the problem, seek advice from your supervisor regarding repair or replacement of the disc or angle grinder .
Before operating an angle grinder, set up, inspect and secure your work area including: Ensure that there are no flammable materials in your area and that it is not a restricted or
hazardous area where grinding is not allowed. Determine if a Permit To Work is required and, where needed, ensure it is obtained,
Avoid using an angle grinder within a confined space. If this is not possible, ensure that a Task Hazard Analysis and any other Confined Space Operations requirements (including permits) have been completed,
Check that your power supply is earth leakage protected, Ensure that your power cord and extension leads are long enough and are positioned out of
Secure the object you are working on in a vice or in an alternative holding device. Do not hold the object you are grinding in your hand unless circumstances preclude any other method of doing the job. Where such circumstances exist, they must be supported by the completion of a formal Task Hazard Analysis that is approved by the work area supervisor, and
When positioning the job and securing the object, consideration must be given to the vibration and noise generated for both the operator and people in adjacent areas.
Ensure that all personnel in the area are a safe distance from the grinding area, If required, erect protection screens to protect other personnel or plant in the area,
When operating an angle grinder: Hold the grinder firmly with two hands and ensure that you will be able to maintain your
balance throughout the job, Maintain the appropriate pressure on the object to avoid damaging the wheel or
overheating the object, Avoid allowing the wheel to rest on one spot for too long. This could cause the work to burn
or the wheel to crack or ‘explode’, Where possible do the work at waist height,
Maintain the grinding disc at a 15° to 30° angle to the work piece, Allow the grinder to reach full speed before commencing work, Allow the grinder to do the work, do not use excessive force, Allow the disc to stop completely before putting the grinder down, and Always lay the grinder down with the disc facing upwards.
2.2.6 Personal Protective Equipment (PPE)
The PPE worn by operators of angle grinder must reflect the activities being performed.
The following PPE is mandatory for operators using an angle grinder: Either safety glasses or goggles and a face shield (to meet the requirements of AS/NZS
1337-1992:Eye Protectors for Industrial Applications) must be worn to protect the eyes and face from the impact of flying objects. Small particles, dusts or bits of the grinding disc may fly off the grinding disc or surface of the object. Welding helmets can only be used when angle grinding if they meet the requirements of AS/NZS 1337 and provide adequate physical protection to the face and neck. Even if a welding helmet meets these requirements, safety glasses or goggles must also be worn,
Hearing protection. Most, probably all, angle grinders exceed 85 dB(A) even before they are applied to the object to be ground or cut and so require the use of hearing protection,
Close fitting cotton clothing that covers the arms and legs must be worn for all grinding operations,
Safety boots with steel capped toes, and Close fitting gloves to aid grip and protect the hands from metal fragments and sparks. If an
operator believes that wearing gloves will introduce a hazard into the task, this must be supported by a formal Task Hazard Analysis and be approved by the work area supervisor.
The following PPE is not mandatory but should be considered for each task: A hood is recommended if the operator is working in a confined space. This will protect the
operator from hot or rebounding particles, and Respiratory protection, possibly including supplied air if working in confined spaces.
3 ACCOUNTABILITIES AND RESPONSIBILITIES
3.1 Site General Manager
The site General Manager is accountable for ensuring that the requirements of this Standard are actively applied across his/her area of responsibility. To the extent practicable, the General Manager is required to formally delegate the responsibilities for achieving the expectations of this Standard to specific individuals within their organisation.
3.2 Supervisors
In addition to any specific responsibilities that are delegated by the site General Manager, any person employed in a Supervisory capacity has a number of General Accountabilities arising from the WMC EHS Standards. In the context of this Standard, these include the following:
Supervisors must provide a safe and healthy workplace for the personnel reporting to them by ensuring that: they understand the hazards associated with the work they are allocated and actively apply
“Take Time, Take Charge” to their day-to-day activities, the Hierarchy of Controls has been applied to all identified hazards and the procedures /
Task Hazard Analyses and other controls needed to work safely are in place, understood and actively applied,
they have the appropriate tools, equipment, licences, skills, induction and training to safely undertake their tasks, and
they are fit for work.
Supervisors must ensure that all activities in their area of responsibility comply with all relevant: legal obligations and licence conditions, WMC EHS Management System Standards, and WMC Major Hazard and General Hazard Standards; and where a non-conformance is found, take corrective action.
3.3 Personnel Using Angle Grinders
All personnel using angle grinders must undertake their work safely by: understanding the hazards associated with all work to be done ensuring that the procedures, Task Hazard Analyses and other controls measures are
understood and actively applied applying the “Take Time, Take Charge” approach reporting all incidents and unacceptable hazards, and
4 REFERENCES Australian Standard AS1788.1-1987 “Abrasive Wheels – Design, construction and
safeguarding” Australian Standard AS1788.2-1987 “Abrasive Wheels – Selection, care and use” Worksafe Western Australia, Toolbox Topic 7 – Angle Grinders
5 SUPPORTING DOCUMENTATION WMC EHS Powerpoint Presentation – “Safe Use of Angle Grinders”
(web.wmc.com/EHSMS/Management System/training and presentations/Angle Grinders.ppt)
APPENDIX A Summary of Data from Incidents Involving Angle Grinders
A review of 61 grinding related incidents in the Western Australian Department of Industry and Resources (DOIR) Mining Industry injury database for 1994 – 2001 shows the following breakdown of incident mechanisms:
43% - Electrical
33% - Sparks / hot metal
16% - Disc jammed / kickback
5% - Slip (of tool) / object moved
3% - Disc shattered / ‘exploded’
A similar review of 58 WMC grinding related incidents for the period 2000 – 2002 shows the following incident mechanisms :
27% - Struck by flying object (inc into eyes)
21% - Sparks / hot metal
19% - Contact with rotating disc (no jam)
14% - Electrical
9% - Disc jammed / kickback
8% - Slip (of tool) / object moved
2% - Lifting (of tool)
70% of the Disc jammed / kickback incidents in the WA DOIR data and 83% of similar incidents in the WMC data occurred when the angle grinder was being used for cutting operations.
The WMC incidents resulted in the following breakdown of injuries / incidents:
25% - Cuts to hands or arms
22% - Foreign body in eye
21% - Fires and/or burns
14% - Electric shock or equipment trip out
8% - Cuts (other than to hands /arms)
8% - Other or no damage / injury
While the frequency of angle grinder discs shattering is low compared with other mechanisms of injury, the consequence of such an incident can be very severe, including permanent disability and death.
APPENDIX B Generic Procedure for Changing a Disc on an Angle Grinder
It is important to note that this is a generic procedure only. Procedures for changing a disc on an angle grinder may change from one unit to another. You must always follow the manufacturer’s instructions for the unit you are using.
The procedure for installing a new disc is described below. Turn power off and unplug the grinder
before replacing a disc. Ensure all necessary equipment is
assembled before replacing the grinding disc.
Screw the handle on to the right or the
left side of the machine head depending on the working method.
spindle collar of the machine head. Turn the guard anticlockwise to the required working position. To fasten the protective guard, close the clamping lever.
Install the backing plate and ensure it is
seated correctly on the arbour.
Ensure the disc is appropriately installed
and centred before you tighten the locknut. Ensure that the arbour hole is the correct size for the grinder to be used.
washer assembly is in good condition and is matched to the disc type.
Do not use any tool or implement other
than the correct spanner to change a disc.
Tighten the locknut assembly carefully
and firmly by hand. Do not use a hammer or any tool to tighten the locknut.
Conduct a ‘test start’ to check the angle grinder for balance and vibration. If unusual and/or
excessive vibration is encountered during the test or at any time during use, immediately stop work , unplug the unit, remove the disc and inspect it and the angle grinder for damage or incorrect mounting. If you are unable to locate and/or correct the problem, seek advice from your supervisor regarding repair or replacement of the disc or angle grinder .
APPENDIX C Summary of Angle Grinder Hazards and Safe Operation Rules
This Appendix contains a summarised version of the requirements of the Standard.
This information is presented here in a format that will be more useful as handouts at toolbox meetings or for display on noticeboards.
The General restrictions on the use of Portable Angle Grinders are summarised onto a single page in Appendix E to this Standard. The tabulated format used in Appendix E may also be useful as a handout at toolbox meeting or for display on noticeboards.
POTENTIAL HAZARDS
The following types of hazards can occur when using a hand held angle grinder: Electrocution Flying sparks / hot metal / dusts Disc jam / kickback Grinder (or object) slips Disc shatters (‘explodes’) Noise and vibration Hair or clothes caught by rotating disc
Typical injuries and incidents
The most common injuries / incidents that come from using an angle grinder are: Cuts, especially to hands and arms Foreign body in the eye Fires and/or burns Electric shock or equipment trip out
Contributing Factors
Typical contributing factors to incidents involving angle grinders are: Using an angle grinder without a correctly fitted and positioned guard Object being cut / ground not properly secured or positioned, Inadequate, poorly positioned or poorly maintained handles on the angle grinder, Operator fatigue from prolonged use of an angle grinder (holding , supporting, applying
pressure), Use of angle grinders in awkward or unbalanced positions e.g. overhead, in a confined
space or with arms or body extended, Inadequate selection and/or use of Personal Protective Equipment, Lack of skill and/or competency of operator in use of angle grinder,
Angle grinder discs shattering / ‘exploding’ as a result of the following: - use of the wrong disc for the job e.g. cutting disc used for grinding, or an
inappropriate operating speed chosen for the disc in use, - disc not properly installed, - disc not properly maintained or not replaced when worn / glazed, - disc ‘jamming’ during a cutting job, - allowing the wheel to rest on one spot for too long (overheating), - moisture being absorbed into (part of) a disc causing it to be ‘unbalanced’, or - material embedded in a disc from a previous job reacting with material (and heat)
generated in the current job e.g. aluminium grinding followed by steel grinding. Electrocution or electric shock can result from either:
- Disc cutting through the electrical supply cable, or - Poor quality or poorly maintained equipment or cables.
ANGLE GRINDERS – ‘SAFE OPERATION RULES’
Check your equipment before use including:
Inspect the angle grinder to ensure that it is in a safe operational state, Inspect the disc and disc guard. Make sure that they are in place and secure. Ensure that
that the disc or wheel is not chipped, cracked, glazed or damaged in any way that could cause it to shatter or ‘explode’,
Check the handle(s) to ensure that they are secure and not damaged, Check to see that the test tag on the power cord is up-to-date and that the ‘on-off’ and/or
‘deadman’ switch is in good working order, and Conduct a ‘test start’ to check the angle grinder for balance and vibration. If unusual and/or
excessive vibration is encountered during the test or at any time during use, immediately stop work , unplug the unit, remove the disc and inspect it and the angle grinder for damage or incorrect mounting. If you are unable to locate and correct the problem, seek advice from your supervisor regarding repair or replacement of the disc or angle grinder .
Before operating an angle grinder, set up, inspect and secure your work area including:
Ensure that there are no flammable materials in your area and that it is not a restricted or hazardous area where grinding is not allowed. Determine if a Permit To Work is required and, where needed, ensure it is obtained,
Avoid using an angle grinder within a confined space. If this is not possible, ensure that a Task Hazard Analysis and any other Confined Space Operations requirements (including permits) have been completed,
Check that your power supply is earth leakage protected, Ensure that your power cord and extension leads are long enough and are positioned out of
harm’s way, Ensure that all personnel in the area are a safe distance from the grinding area, If required, erect protection screens to protect other personnel or plant in the area,
Secure the object you are working on in a vice or in an alternative holding device. Do not hold the object you are grinding in your hand unless circumstances preclude any other method of doing the job. Where such circumstances exist, they must be supported by the completion of a formal Task Hazard Analysis that is approved by the work area supervisor, and
When positioning the job and securing the object, consideration must be given to the vibration and noise generated for both the operator and people in adjacent areas.
When operating an angle grinder:
Hold the grinder firmly with two hands and ensure that you will be able to maintain your balance throughout the job,
Maintain the appropriate pressure on the object to avoid damaging the wheel or overheating the object,
Avoid allowing the wheel to rest on one spot for too long. This could cause the work to burn or the wheel to ‘explode’,
Where possible work at waist height,
Maintain the grinding disc at a 15° to 30° angle to work, Allow the grinder to reach full speed before commencing work, Allow the grinder to do the work, do not use excessive force, Allow the disc to stop completely before putting the grinder down, and Always lay the grinder down with the disc facing upwards.
HAZARD CONTROL
Before starting any work with an angle grinder, apply the following principles: Hierarchy of Controls ‘Take Time, Take Charge’ Change Management
Given below is a summary of the controls that are required when using an angle grinder.
Tool selection and maintenance
Ask the following questions: Is an angle grinder the right tool for the job? (especially for cutting jobs) Should the angle grinder be electrically or pneumatically powered? Does the angle grinder have a disc brake? If not, why not? Do you have the right disc / wheel for the job? Consider the size and type. Have the angle grinder and disc / wheel been properly maintained?
General Restrictions on the Use of Angle Grinders at WMC Sites
In addition to the specific restrictions on the use of angle grinders that come out of Task Hazard Analyses or Safe Work Procedures, there are a number of general restrictions on the use of angle grinders at WMC sites. They include restrictions on: people who can use angle grinders, the types and sizes of angle grinders that can be used, and the use of angle grinders without:
- handles, - guards, and - ‘deadman’ switches
Before commencing any job involving the use of an angle grinder you must ensure that none of these restrictions apply.
Pneumatic and Electrical Tool Safety
General controls for the use of pneumatic or electrically powered tools include: Never use electrical grinders in wet or damp conditions, Always ground electrical tools correctly prior to use, Ensure that the air pressure supply is, and remains, within the specified operating limits.
Training and Awareness
The safe and effective use of an angle grinder requires the operator to have the appropriate skills. In most circumstances, people with a Metals trade Certificate will have these skills. The Standard imposes restrictions on the use of angle grinders by people who do not have these skills, including an appropriate awareness of this standards requirements .
Personal Protective Equipment
The PPE worn by operators of angle grinder must reflect the activities being performed.
The following PPE is mandatory for operators using an angle grinder: Goggles with a face shield, Hearing protection, Close fitting cotton clothing that covers the arms and legs, Safety boots with steel capped toes, and Close fitting gloves,
The following PPE is not mandatory but should be considered for each task: A hood is recommended if the operator is working in a confined space, and Respiratory protection, possibly including supplied air if working in confined spaces.
APPENDIX D Template for a Site Approval Form for ‘Use of Cutting Discs > 127mm’
The Approval Form on this page must be used to gain approval for the use of an angle grinder with a cutting disc > 127mm (5”) as required by Section 2.2.2 of this Standard.
SITE APPROVAL FORM FOR ‘USE OF CUTTING DISCS > 127MM’ The use of any cutting disc by Non ‘Trades or Metals Trade’s personnel is not permitted and the use of cutting discs larger than 127mm (5”) by ‘Metals Trades’ personnel is restricted. Approval shall only be granted by the immediate supervisor of the work if all other practicable cutting methods are inappropriate for the work. All efforts must be made to identify an alternative cutting method to ensure safety. Convenience is not an acceptable justification for approval.
Immediate Supervisor Review (answer questions and complete section below)
Supervisors are responsible for finding alternate work methods where practicable to avoid the use of cutting discs in angle grinders.
YES NO
Can the material be moved to fixed workshop saws, ie bandsaw, drop saw
Can a portable saw be taken to the work area (drop saw etc)
Can a different tool be used (oxy acetylene, plasma cutter etc)
Is this request based on convenience instead of a genuine requirement
If the answer to any of these questions is YES, approval shall not be granted. If all questions above are answered NO, approval may be granted by the supervisor when a formal Task Hazard Analysis (THA) or Safe Work Procedure has been supplied for the cutting disc work and the risk associated with the task has been deemed to be acceptable by the supervisor.
The use of a cutting disc > 127mm is Approved / Not Approved (circle as appropriate)
APPENDIX E Summary of General Restrictions on the Use of Portable Angle Grinders
The tabulation below is a summary of the General Restrictions on the use of Portable Angle Grinders set down in Section 2.2.2 of this Standard. The reader should refer to this Section for the exact wording of the restrictions.
Non ‘Trades or
Metals Trades’
personnel
‘Trades’ Personnel
‘Metals Trades’1
personnel
‘Deadman’s Switch
Handles Guards Override (‘Lock-
on) Switch
Anti
kick back
device
Tungsten Tips
Grinding wheel
≤ 127mm (5”)
√
√ √ R M3 M4 Χ R5 Χ6
Cutting disc
≤ 127mm (5”)
Χ √ √ R M M4 Χ R5 Χ6
Grinding wheel
> 127mm (5”)
Χ Χ √ M M M4 Χ R5 Χ6
Cutting disc
> 127mm (5”)
Χ Χ √1 M M M4 Χ R5 Χ6
Cutting disc or grinding wheel
> 185mm (7”)
Χ Χ √2 M M M4 Χ R5 Χ6
Legend √ = Permitted: Χ = Not Permitted: R = Recommended: M = Mandatory
Footnotes / Conditions
1. ‘Metals Trades’ personnel who need to use an angle grinder with a cutting disc greater than 127mm (5”) can only do so after completing, and having approved by their line supervisor, the form included as ‘Appendix D’ to this Standard. This form will not be approved until a formal Task Hazard Analysis (THA) has been completed or a Safe Work Procedure is produced
2. The use of an angle grinder with either a grinding wheel or a cutting disc > 180mm (7”) is only permitted with specific approval on a ‘job-by-job’ basis of the work area supervisor. If a cutting disc is to be used, the form in Appendix D must be completed as above
3. All angle grinders must be fitted with handles that meet the manufacturer’s specifications. This restriction can be revoked for an angle grinder that is to be used with a grinding wheel <127mm (5”) for a task where a formal Task Hazard Analysis has been completed and there is specific approval on a ‘job-by-job’ basis by the work area supervisor
4. All angle grinders must be fitted with ‘correctly fitted and positioned’ guards that meet the manufacturer’s specifications. This restriction can only be revoked after completion of a formal Task Hazard Analysis and with specific approval on a ‘job-by-job’ basis of the work area supervisor
5. It is recommended but not mandatory that angle grinders be fitted with anti-kickback devices. This includes electric grinders fitted with a clutch that disengages the disc if it becomes jammed, and compressed air grinders that stall rather than kick back
6. The use of cutting discs fitted with tungsten tips is only permitted with specific approval on a ‘job-by-job’ basis of the work area supervisor.
A requirement of this Standard is that Supervisors must ensure that personnel using angle grinders are able to do such tasks safely (Section 2.2.4). Given below is a series of questions and requirements that a Supervisor can use to assist them in determining if an operator has sufficient understanding of the specific requirements of this standard before allocating them any tasks involving the use of angle grinders or to periodically reassess that understanding.
Practical Skills
1. Does the person hold a Trades Certificate in a Metals Trade such as Boilermaking or Fitting & Machining?
2. If Yes to Q1, did their apprenticeship / training for this certificate include practical experience in the use of angle grinders?
3. If No to Q1, has the person undergone any formal training programme that includes practical experience in the use of angle grinders?
4. If No to Q2 or Q3, or if Yes but the most recent use of an angle grinder was more than five (5) years ago, the Supervisor must either ensure the person undertakes some formal training in the use of an angle grinder or successfully completes a practical demonstration of a task similar to that to be undertaken in the workplace.
Knowledge of the Requirements of this Standard
1. Is the person able to describe the primary hazards associated with the use of portable angle grinders? (Section 2.1)
2. Is the person able to describe other hazards associated with the use of portable angle grinders? (Section 2.1)
3. Is the person able to describe the Contributing Factors to the hazards associated with the use of portable angle grinders? (Section 2.1)
4. Is the person able to describe the three main principles of hazard control that are practised throughout WMC operations? (Section 2.2)
5. Is the person able to describe the general considerations that must be made regarding proper tool selection and equipment maintenance for angle grinding tasks? (Section 2.2.1)
6. Does the person fully understand the General Restrictions on the use of portable angle grinders that are in force at WMC operations? (Section 2.2.2)
7. Does the person have experience and training in conducting ( and/or participating in) a Task Hazard Analysis? (Section 2.2.2)
8. Is the person able to describe the general safety requirements for the use pneumatic and electrical powered angle grinders? (Section 2.2.3)
9. Is the person able to describe the ‘safe operation rules’ for the use of portable angle grinders? (Section 2.2.5)
10. Is the person able to describe the Personal Protective Equipment requirements for the use of portable angle grinders? (Section 2.2.6)
