the “minor service” exception -...
TRANSCRIPT
The “minor service” exception
Presented by:
Carol Robinson CSP, CIH and
Debby Shewitz CSP
June 25, 2013
Video clip
What is the minor servicing exception?
What issues exist around the use of “minor service exception” to the Lockout/Tagout standard?
What criteria do protective devices have to follow to allow them to be used during minor servicing?
What should you be looking for at your facility?
1977: LOTO rulemaking started
August 1989: Minor servicing language inserted by OMB
September 1989: LOTO final rule issued
January 31, 1990: LOTO rule went into effect
February 14, 1990: Westvaco case is the first test of the definition of “minor servicing”
February 2008: Most recent update of CPL 02-00-147 with expanded details about minor servicing
Servicing and Maintenance
Covers “servicing and maintenance of machines and equipment in which the unexpected energization or start up of the machines or equipment, or release of stored energy could cause injury to employees”
Normal Production
Only covers servicing and maintenance during normal production if an employee is:
◦ required to remove or bypass a guard or other safety device;
◦ required to place any part of his or her body into point of operation or danger zone*.
*Reference: 29 CFR 1910.147(a)(1)) and (a)(2)
Lockout/Tagout
Machine Guarding
Minor servicing
exception
Electrical Safety
Workplace activities such as:
Constructing
Installing
Setting up
Adjusting
Inspecting
Modifying
Maintaining
Servicing
. . . machines or equipment.
Also lubrication, cleaning or
unjamming of machines or
equipment and making
adjustments or tool changes,
where the employee may be
exposed to the unexpected
energization or startup of the
equipment or release of
hazardous energy
take place during normal production operations;
routine, repetitive, and integral to the use of the equipment for production; and
work is performed using alternative measures which provide effective protection, e.g., through guarding (Note to 29 CFR 1910.147(a)(2)(ii)). This note specifically refers the employer to Subpart O – “Machinery and Machine Guarding”
Minor tool changes and adjustments, and other minor servicing activities are allowed without LOTO if:
Many people do not connect these two OSHA issues!
They interact when an employee does “minor servicing” or jam-clearing and “bypasses” normal protections
Note that de-energized parts that are not locked out must be treated as if energized, e.g., qualified people with appropriate PPE*
Only electrically qualified employees may bypass electrical safety interlocks*
*References 29 CFR 1910.333(b)(1)) and (c)(9)
Inspections related to quality
Inspections related to the product
Inspections related to troubleshooting
Inspections to confirm machine repair
See also:
www.dleg.state.mi.us/wsh/docs/inst/gishd_com_07_3.doc
Sources of Risk Assessment Guidance
NFPA 79 - Electrical Standard for Industrial Machinery
ANSI/ASSE Z244.1 - Control of Hazardous Energy Lockout/Tagout and Alternative Methods
ANSI B11.19 1990 or 2003 - Performance Criteria for Safeguarding
ANSI B11-TR3-2000 - Risk Assessment and Risk Reduction – A Guide to Estimate, Evaluate and Reduce Risk
ANSI/RIA 15.06 – Safety Requirements for Robots and Robot Systems
Guidance from ANSI/ASSE Z244.1Annex A
Identify all Tasks
Identify Hazards
Assess the Potential Consequences
Assess the Potential Exposure to the Hazards
Assess the Probability of Occurrence
Evaluate the Risk
Achieve an acceptable level of risk
Machine Name: Filler Location: Fill Room
Risk Assessment by: Joe Smith Risk Assessment Date: 2/27/2012
Task Hazard Consequences Current Controls
Seve
rity
Fre
qu
en
cy
Pro
bab
ility
Risk Level
Acc
ep
tab
le?
Unjamming bottles Exposure to moving machine parts Loss of hand
Which of these would be acceptable alternative measures?
Engineered safeguards techniques.
Warning and alerting devices.
Administrative controls.
Personal protective equipment.
Eliminate the hazard through design.
Lockout
Could any of these be used as alternative measures?
OSHA’s point of view (CPL 02-00-147) ◦ Key is that they must be “equivalently effective”
A guard that adequately
protects during normal
operation may not be
adequate for servicing
(pg 2-24) Example: light curtains or
presence-sensing devices
System that relies on
PLC are typically not
suitable (pg 1-5) Potential for failure due to
component failure, program
errors, magnetic field
interference, electrical surges,
improper use, maintenance,
etc.
Any device that is
allowed (see following
slides) must be under
exclusive control of the
person doing service Continuously in a position to
prevent (exclude) other
individuals from re-energizing
the machine or equipment
No “calling over” from one
person to another in pairs on
control system
Push-buttons, selector
switches, safety
interlocks and other
control circuit type
devices are generally
NOT acceptable energy
isolating devices High potential for failure in
“wrong mode” or mis-
selection
List of OSHA energy control
devices is at CPL pg 1-5;
most are manually actuated
single control devices
Simple tools are often used to keep the employee a safe distance from the machine while performing the minor servicing task.
These can be fine – need to think about what happens if tool gets caught in machine, contacts electrical that is turned off but not locked, etc.
A system initiated by human action intended to shut down a machine in an emergency
20
Three categories of stop functions:
Category 0: An uncontrolled stop by immediately removing power to the machine actuators.
Category 1: A controlled stop with power to the machine actuators available to achieve the stop then remove power when the stop is achieved.
Category 2: A controlled stop with power left available to the machine actuators.
Per NFPA 79
How does the E-Stop function?
◦ Most people do not know!
◦ Look for manufacturer certification as “fail safe”
◦ Restart Provision?
◦ Exposure to electrical circuits?
◦ What does it do to other hazards such as gas, heat, air?
Potential exclusive control issue in service application
a device that prevents unsafe actions or adjusts equipment to a safe state if an unsafe action is taken
22
Examples:
An electromechanical
switch (like a limit or
magnetic switch)
Single-beam light curtain
Picture University of Waterloo
Questions to ask: ◦ Interlock device certified/tested/maintained?
Typically requires a “high reliability interlock switch”
◦ Stored energy/other types of energy?
◦ Exposed power points?
Light curtain design flaws, e.g. do curtains operate in the “inch mode”?
24
Light curtain
The devices discussed are often controlled by a programmable logic controller (PLC).
PLC’s are not energy isolating devices for purposes of the LOTO standard.
To be acceptable, PLC must be designed, installed, used, and maintained on a case-by-case basis in accordance with generally-recognized good engineering practices
See also LOI dated 1/25/2008:
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=I
NTERPRETATIONS&p_id=25947
“Performance Criteria for Safeguarding”
Describes alternative approaches ◦ OSHA has accepted certain approaches if done
according to this performance standard
◦ Manufacturer designed and tested interlocks, presence-sensing devices and “fail-safe E-Stops”
◦ See page 3-37 et seq of CPL 02-00-147 for examples
All items that meet standard typically require periodic inspection, maintenance, and testing
◦ When is the last time you tested all your interlocks?
Intermediate Energy
State - Three Phase
Disconnect
Intermediate Energy
State – Machine
Safeguard Key
Pictures from Geo. M. Martin Company
Inspection of dies during operation
LOI: Employer must demonstrate that the minor servicing exception applies.
If it does, must provide alternative safeguarding measures
•Printing press rollers cleaned periodically during the work shift to ensure quality control.
•LOI: Alternative means required to comply with minor servicing exception: “Inch Safe”
High volume envelope feeder – light pressure is frequently needed to keep envelopes moving.
Mail Opener and insert sorter
• No residual hazard when guard is lifted
• Single operator
• Requires positive action to restart
High Volume Analysis Equipment
• Robot
• Carousel
• Liquid Handling Module
Use of the “minor service” exception to LOTO is a lot more complicated that it first appears
Identification of operations where you might want to use the exception needs to be done up-front (at design/installation phase, or through survey of all equipment).
An effective risk assessment helps identify issues (all energy source, particularly stored/potential energy)
Guarding that is effective during normal operations may not be appropriate under non-routine conditions - especially if used as an alternative to LOTO.
Equipment and guarding installed prior to 2004 needs extra attention to ensure that it reliable enough to provide effective protection as an alternative measure.
If you don’t use full LOTO, you have to use an equally protective alternative
If You Take Away Nothing Else..
It’s got to be
evaluated on
a case-by-
case basis
You really have to do some level of risk assessment
OSHA’s OSHA CPL 02-00-147
◦ http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=DIRECTIVES&p_id=3809
OSHA’s Lockout/Tagout e-tool
◦ http://www.osha.gov/dts/osta/lototraining/index.html
ANSI B11.19 2003 Performance Criteria for Safeguarding
ANSI Z244.1 - 2003 (R2008) Control of Hazardous Energy Lockout/Tagout and Alternative Methods
MIOSHA Instruction
◦ www.dleg.state.mi.us/wsh/docs/inst/gishd_com_07_3.doc
MIOSHA Alternative Measure Decision Making Tool - Posted on SafetyNet
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