Portable Electric
Grinder Safety
Manufacturing Standard GR - 150
© Chevron
Chevron
Rev.
2006
Aug. 2011
1
Overview
Purpose
The purpose of this Mfg Standard is to protect personnel by
specifying the requirements for portable grinders within the
refinery
Objectives
This document is intended to highlight the safety precautions
required for using portable electric grinders within the
refinery. These precautions are to work in conjunction with
industry standards, manufacturing standards, and established
risk mitigation practices. The more stringent to apply.
Scope
This standard applies to employees and contractors alike
whose work involves the use of portable electric grinders
within the refinery.
© Chevron
Chevron
Rev.
2006
Aug. 2011
2
Procedures, Standards, and Guidelines
Portable grinders are one of the most potentially dangerous
tools on any worksite. The majority of injuries associated
with portable grinder use are foreign bodies in the eyes and
lacerations to the body. These injuries typically result from
one or more of the following items:
1.Improper selection of tools
2.Improper use or operation of the grinder
3.Failure to utilize the correct personal protective equipment
4. Improper abrasive/ grinding wheel selection
5.Incorrect body positioning and/or improperly inspected and
maintained equipment
© Chevron
Chevron
Rev.
2006
Aug. 2011
3
Required Safety Features for Portable Grinders
1.Lock-off switch to prevent accidental starting of the portable grinder. The
main operating trigger will automatically return to the OFF position when
released. An unlocking action is required to start. The paddle switch shall
not take up the length of grinder so that a good grip can be maintained
when the start switch is released.
2.No lock-on switch to prevent the user from locking the grinder in the run
position. Lock-on switches are not allowed.
3.Anti-kickback Clutch will disengage the rotating wheel from the motor
when the wheel is pinched or a stall is detected. This reduces kick- back
significantly.
4.Tool free adjustable guard protects from debris.
5.Quick disk change allows for tool free disk change of worn out disk.
6.Adjustable side handle allows for stability control of the grinder for right or
left-handed users.
© Chevron
Chevron
Rev.
2006
Aug. 2011
4
Desired but not required
1. A brake that allows for the rotating disk to stop rotating quickly once the trigger
is released.
2. A soft start allows the disk to slowly ramp up preventing the jerk upon start up.
3. Vibration reducing features to improve ergonomics.
Grinder approval process
1. Chevron procurement will ensure that suppliers provide only those grinders that
meet these requirements.
2. Contractors will ensure their employees use only approved grinders.
3. Chevron maintenance supervisors and projects reps are responsible for ensuring
that only approved grinders are used on their jobs.
PPE Requirements
1. Standard PPE
2. A hard hat w/impact resistant face shield or welding hood will be worn whenever
grinding.
3. Goggles or equivalent sealed eyewear will be worn under the face shield.
© Chevron
Chevron
Rev.
2006
Aug. 2011
5
Safe Operation
1. As a rule grinders should not be used as a cutoff tool. A powered saw,
chop saw, or another approved cutting tool is preferable. An exception
form is required to use a grinder as a cut off tool
2. Always follow manufacturers instructions.
3. Always unplug grinder before changing disk or making adjustments.
4. Always replace worn wheels in accordance with mfg. instructions. Make
sure the wheel is rated for the grinders speed, size, and service.
5. Never wear an abrasive wheel down to its backing flange/plate.
6. Wheels that are cracked, dropped, not marked with a speed rating, wet
or contaminated with material shall not be used.
7. Never use your foot, hand, or any part of your body to secure the object
while in the process of grinding.
8. To prevent kickback don’t bump the grinder onto the work surface or let
the abrasive wheel contact adjacent surfaces while grinding.
9. Guards shall never be removed to accommodate larger disks.
10.Do not lay the grinder down while the abrasive wheel is still rotating.
© Chevron
Chevron
Rev.
2006
Aug. 2011
6
Daily Portable Grinder Visual Inspection
A daily portable grinder visual inspection shall be completed prior to each use
and periodically during extended use. Wheels shall be closely inspected and
sounded.
Abrasive Wheel
1. Rated for grinder speed (RPM).
2. Free of physical damage and imperfections.
3. Not wet or contaminated.
Guard - Attached to grinder while in use.
Body of Tool
1. Free of physical damage.
2. Power cord is free of nicks, cuts or abrasions.
3. Grab handle is attached and secure.
Portable Grinder Safety Awareness Training Requirements
1. All Chevron and contract personnel who use portable grinders are
required to take Grinder Safety Awareness Training.
2. Chevron personnel will receive the portable grinder safety training as
part of their normal craft training. In addition, a CBT refresher will be
required every two years.
3. Contractors are responsible for ensuring their employees are properly
trained and qualified in using portable grinders. They shall be able to
show proof upon request that employees have been trained.
© Chevron
Chevron
Rev. Aug. 2011
7
2006
Portable Grinder Safety Awareness Training
Requirements

Audits and Review
Maintenance Team Leaders and Chevron Contractor
representatives are responsible for auditing adherence to this
standard.

Exceptions
Exceptions to any part of this standard shall be issued and
approved prior to work commencing.
The Chevron Maintenance Team Leader or Company
Representative shall approve exceptions to this standard.
© Chevron
Chevron
Rev.
2006
Aug. 2011
8
Roles and Responsibilities
The following table outlines the roles and responsibilities
associated with this process.
Role
Responsibilities
Chevron Maintenance
Team Leader or Project
Supervisor
Ensure the requirements of this standard are followed
by performing frequent audits.
Contractor site
leadership
Ensure the requirements of this standard are
understood and followed.
Approve any exceptions to this standard and ensure
mitigation steps are in place to prevent injury.
Ensure workers are trained on grinding and provide
documentation that your company certifies each
employee is capable of performing grinding work
safely.
© Chevron 2006
Roles and Responsibilities
Role
Responsibilities
Contractor site leadership
Ensure workers are trained in the requirements
of this standard.
When required, issue exceptions to this
standard with appropriate mitigation steps to
ensure the job can be performed safely.
Mechanic (Chevron or Contract)
Complete awareness training and fully
understand the requirements of this standard.
Follow safe operating guidelines in this
standard to ensure Incident and Injury Free
work.
© Chevron 2006
Roles and Responsibilities
Roles
Responsibilities
Mechanic (Chevron or
Contract)
Perform daily inspections of the grinder per the
requirements of this standard.
Review and follow the manufacturer’s
documentation.
Procurement
Ensure suppliers of portable grinders are aware of
our requirements.
Ensure contractors understand our requirements
for portable grinders.
Maintenance Training
Department
© Chevron 2006
Incorporate Grinder Safety Awareness standard
into the Formal Maintenance Training Program.
Ensure successful training.
Portable Grinder Exception Form
This form shall be used to gain approval for any exception to GR-150, Portable Grinder
Safety standard. Appropriate description of the proposed exception along with risk
mitigation shall be
clearly defined below. Any employee who is involved with this exception shall read
and sign this form stating they fully understand the exception and risk mitigation steps.
Company Name: __________________
Date____________________________
Supervisor: ________________________Date: _______________________
Proposed Exception _____________________________________
_______________________________________________________________________________________________________________________________
_______________________________________________________________________________________________________________________________
_______________________________________________________________________________________________________________________________
___________________
Risk Mitigation ________________________________________
_______________________________________________________________________________________________________________________________
_______________________________________________________________________________________________________________________________
_______________________________________________________________________________________________________________________________
___________________
Mechanics Assigned to use Portable Grinders with this Exception :
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Print Name
Date
Approved:
Yes
No
Chevron Maintenance Team Leader or Company Representative:
Name:
© Chevron 2006
Name
Date:
Grinder Hazard Check List
Before Use Check
You are wearing your protective equipment including goggles/spoggles full face
visor & dust mask (depending on material)
Any work that is not part of a fixture should be securely clamped or held in a
vice.
Ensure the tool is in current PAT
Check that the abrasive wheel is fitted correctly & securely, and that the guard is
properly adjusted. Check disc is of correct rating for task.
Ensure the handle is fitted as per manufacturers instructions.
You can only change an abrasive wheel if you are trained to do so.
Check that the abrasive wheel is clear of any obstruction before switching on.
During Use
Be prepared for large grinders to kick when starting up.
Let the grinder run up to speed before contact with the work surface.
Keep the wheel running at speed: if machine starts to labour and slow down do
not force it so hard. Firm but steady.
Use both hands to control the grinder on the correct handles.
Lift the abrasive wheel clear of the work before switching off. The abrasive
wheel will continue to rotate for a few seconds after switching off. Wait for it to
stop before you put the grinder down.
Switch off and stop work if someone approaches you.
Watch out for signs of that vibration may be affecting your hands. If your fingers
start to tingle or feel numb, take a short break from using the grinder. Exercise
your fingers to encourage blood circulation.
Make sure the machine ventilation slots do not become blocked with debris or
dust.
Keep the cable clear from the abrasive wheel and any sharp edges.
If you think the cable may be cut or damaged in any way, switch off and unplug
at the mains before inspecting it.
Switch off and unplug before leaving the machine unattended.
After Use
Switch off and isolate supply
Clean the tool and work area.
PPE
Assess
© Chevron 2006
the risk
Analyze
how to reduce the risk
Act
to ensure loss-free operation