SAFE WORK INSTRUCTIONS FOR
Electropolishing using 5% of Perchloric Acid Solution
Campus:
Clayton
Department:
Materials Engineering
Room No:
G186
Other:
Assessment Date:
Faculty:
Building:
Engineering
37
Assessment Team:
Investigator
Name of Researcher
Name of Project Supervisor
Name of Academic in charge
Phone
Signature
Handling, use, storage and disposal of Perchloric Acid Electropolishing Solution
1.
Initial Procedures
1.1
Do not proceed if you have not attended the appropriate induction and training courses
for the handling and use of electropolishing equipment and solutions.
1.2
Ensure fume cupboard is clean, clear, operational, switched on, and the hood is closed to
the minimum opening required for safe operation. Check date of previous fume cupboard
flow test – tests must have been performed at 12 monthly intervals. Ensure the
appropriate spill kit is available. Switch off ALL electrical equipment within the fume
cupboard.
1.3
Inspect Personal Protective Equipment (PPE) to ensure that it is appropriate for use with
the solution and in good condition, i.e. gloves, safety glasses, face shield, lab coat,
organic vapour respirator, plastic apron. Ensure other clothing is appropriate, i.e. long
trousers, enclosed shoes, long sleeves, etc. Don appropriate PPE, i.e. safety glasses,
gloves, lab coat.
1.4
Ensure the electropolishing equipment is clean. Check for acid contamination e.g.
discoloured spots, corrosion product etc. on both the apparatus and the paper towels upon
which it rests. If you suspect that the equipment has not been cleaned properly,
record this in the logbook provided AND report this observation to either Joanne
Etheridge or Renji Pan. Clean the equipment as per Items 3.1, 3.2 and 3.3, with the
exception that washing methanol used only for the pre-wash is used, label as washing
methanol no. 1 - ensure that it has been used a maximum of 4 times, i.e. maximum of 5
total washing cycles.
1.5
Ensure all equipment and materials are available and are in appropriate locations, e.g.
specimen in holder, liquid nitrogen, electropolishing solution, etc.
1.6
The safeguards detailed in this document must be adhered to by all persons who use
solutions of methanol and nitric acid. It should be remembered that, as well as being
potentially explosive, these solutions are toxic, very corrosive and highly flammable.
2.
Electropolishing
Once the electropolishing solution has been prepared.
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2.1
Use a face shield for transferring electropolishing solutions from the storage cabinet to
the fume cupboard and vice versa. Remove the electropolishing solution from storage
cabinet and place in the fume cupboard. Use two hands on the body of the Winchester.
Carry the Winchester close to your body – do not pick up by the “neck” (may shatter).
Check the use by date of the solution – do not use if it is in excess of 1 month old. Take
expired solutions to the SPME Technician responsible for disposal – do not pour into
another container. If the solution is discoloured or evolving gas, dispose of immediately
in accordance with Item 6.5.
2.2
Lower fume cupboard sash so that the face is protected (well below the maximum
opening width) – also wear safety glasses. Ensure that electropolishing unit is turned off
at the power source. Turn specimen voltage dial to 0 V on the Tenupol 3. Tenupol 5 does
not allow manual adjustment of voltage. Carefully pour the electropolishing solution into
the plastic electropolishing base container. Place the electropolishing unit on the base
container. Place thermometer for temperature measurement in the solution – note
temperature of solution. Loosely replace cap on the labelled electropolishing solution
Winchester and return to appropriate storage cabinet.
2.3
Place cooling methanol pump in the empty cooling vessel and connect cooling hoses to
the cooling methanol pump and electropolishing unit.
2.4
Remove the cooling methanol from the storage cabinet and place in the fume cupboard.
Open container and carefully pour 1.5L of cooling methanol into the cooling vessel. Seal
cooling methanol Winchester and replace in the storage cabinet.
2.5
Place 1.5L dewar of liquid nitrogen in the fume cupboard. Start cooling pump and
carefully pour liquid nitrogen into cooling vessel. Observe temperature of
electropolishing solution – lower the temperature to –25°C±5°C. Do not pour liquid
nitrogen excessively quickly into the cooling vessel.
2.6
Insert specimen holder with specimen into the apparatus. When using the Tenupol 3, set
electropolishing pump flow rate to minimum and ensure that the voltage is set at 0V.
Turn on the electropolishing unit at the power source.
2.7
Start electropolishing cycle. When using the Tenupol 3, slowly ramp pump flow rate and
applied voltage to the desired levels. Tenupol 5 follows a pre-programmed ramping
facility with regard to pump flow rate and applied voltage, and can not be ramped
manually.
2.8
Maintain electropolishing solution temperature at –25°C±5°C at all times by slowly
adding liquid nitrogen to the cooling methanol as required.
2.9
Prepare 3 covered glass beakers of high purity ethanol for washing of specimen and
specimen holder. Place inside the fume cupboard.
2.9
When specimen is perforated, the electropolishing pump will automatically switch off
and the current in the electrical circuit is reduced to 0. On the Tenupol 3, manually set
specimen voltage to 0V and minimise the flow rate.
2.10
Remove sample holder and rinse in the 3 covered beakers of high purity ethanol.
WARNING: Ensure that the sample holder is dry before re-insertion into the
electropolishing unit for polishing of the subsequent sample. This is to ensure that there is
no ethanol contamination of the polishing solution. It should be remembered that ethanol-
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nitric acid mixtures are HIGHLY UNSTABLE and POTENTIALLY EXPLOSIVE,
and MUST be avoided.
2.11
When you have finished your session, turn the cooling methanol pump off and disconnect
the cooling methanol hoses from the pump. Remove the electropolishing unit from the
base container and immediately place the unit in a clean base container containing 1.5L
of clean water in preparation of washing.
2.12
Retrieve the appropriately labelled Winchester for the electropolishing solution from the
storage cabinet. Carefully pour the electropolishing solution into the Winchester using a
clean glass funnel. Replace the lid but do not tighten. Return the Winchester of
electropolishing solution to the storage cabinet. The base container that held the
electropolishing solution during unit operation should be triple washed with clean fresh
water.
3.
Cleaning of Equipment
THE
IMPORTANCE
OF
APPROPRIATE
CLEANING
OF
THE
ELECTROPOLISHING UNIT CAN NOT BE OVERSTATED. IT IS CRITICAL
THAT THE FOLLOWING PROCEDURE BE ADHERED TO. FAILURE TO DO
SO MAY RESULT IN CONTAMINATION OF ELECTROPOLISHING SOLUTIONS
AND POTENTIAL EXPLOSIONS. INDIVIDUALS WHO FAIL TO FOLLOW
PROCEDURE WILL HAVE THEIR USER-LICENCE REVOKED.
3.1
From the previous step, the electropolishing unit should be sitting on a base container
containing 1.5L of water. When using Tenupol 3, ensure that specimen voltage is set to
0V and pump flow rate is minimised. Start electropolishing pump and slowly ramp flow
rate to a value of 6. Run pump for 5 minutes. Stop electropolishing pump. Dispose of
water down the sink, flushing with sufficient quantities of fresh water. Use a squeezebottle containing water to douse and rinse the underside of the electropolishing unit i.e.
that part of the apparatus that is not immersed in the washing water.
3.2
Repeat Item 3.1 twice, i.e. total of three washes with water, each of 5 minutes duration.
3.3
Fetch washing methanol no. 2 bottle from cupboard - ensure that it has been used a
maximum of 4 times, i.e. maximum of 5 total washing cycles. Repeat Item 3.1,
substituting water with washing methanol no. 2. Again, ensure the underside of the
apparatus is rinsed with fresh methanol from a squeeze bottle. Carefully pour washing
methanol no. 2 back into its container and place in the storage cabinet. Record the
number of wash cycles on the methanol container. If the number of total washing cycles
is 5, please see the SPME technician about obtaining a fresh bottle of washing methanol
no. 1. DO NOT USE ETHANOL TO RINSE THE APPARATUS.
3.4
Drain any remaining cooling methanol from the heat exchanger coils in the
electropolishing unit. Dry the electropolishing unit with paper towels. Place unit on clean
paper towels in the holding tray provided.
3.5
Leave the cooling vessel containing the cooling methanol in the fume cupboard to stand
until the temperature rises to approximately 15°C to allow the liquid nitrogen to vaporise.
Carefully pour the cooling methanol into its container and return to the storage cabinet.
3.6
Leave the liquid nitrogen dewar in the fume cupboard for liquid nitrogen to vaporise.
4.
Storage of Electropolishing Solutions
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4.1
Electropolishing solutions are to be stored in a dedicated corrosives cabinet. Ensure that
the cap of the Winchester is loose to allow release of any pressure.
4.2
Inspect solutions on a weekly basis – IMMEDIATELY dispose of any solution that is
discoloured, evolving gas, not working, behaving oddly etc. Refer to Item 6.5.
4.3
Dispose of solutions that are in excess of 1 month old – expiry dates are on the solution
label.
4.4
Ensure procedures for checking dates of solutions are followed.
5.
Transport of Electropolishing solutions
5.1
Electropolishing solutions should be transported in 2.5l Winchesters in safety carriers.
5.2
No more that two 2.5l Winchesters are to be transported at any one time.
5.3
Ensure that lids on Winchesters are loose to allow the release of any pressure.
5.4
Avoid bumping or jolting of the solutions – carry safety carriers by hand – do not use
hand trucks.
6.
Disposal of Expired or Suspect Electropolishing solutions
6.1
Return the expired electropolishing solution in the original Winchester to the SPME
technician responsible for disposal. Ensure that the technician is present when the
solution is returned. DO NOT POUR INTO OTHER CONTAINERS, DO NOT MIX
WITH OTHER SOLUTIONS.
6.2
Winchesters awaiting disposal are to be stored in the ventilated cabinet with lids loosened
to minimise the risk of pressure build-up within the bottle.
6.3
Winchesters of electropolishing solutions are to be disposed of in their original container
by Chemsal. Chemsal will clean the Winchesters and return them to the SPME technician
responsible for preparation and disposal of electroplating solutions.
6.4
Expired solutions are to be disposed of within one month of their expiry date
6.5
Suspect solutions that are evolving gases/esters are to be disposed of immediately.
NOTE THAT THE FOLLOWING PROCEDURE IS FOR SUSPECT SOLUTIONS
ONLY – expired solutions MUST be disposed in accordance Items 6.1 to 6.4.
6.5.1
6.5.2
6.5.3
6.5.4
6.5.5
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Ensure the disposal kit is available: 20l plastic bucket, 1kg NaCO3, and litmus
paper.
Don the following PPE: Face shield, plastic apron, long high grade PVC
gloves. Ensure other clothing is appropriate, i.e. long trousers, enclosed shoes,
long sleeves, etc.
Put approximately 15l of water in the 20l plastic bucket, labelled Suspect
Solution Disposal, provided in the laboratory.
Gently pour the suspect solution into the water. Note that the water will dilute
and cool the solution, and that the methanol and methyl nitrate esters are
soluble in water.
Gently pour approximately 500g of NaCO3 into the bucket whilst stirring
gently to neutralise the solution.
6.5.6
6.5.7
6.5.8
6.5.9
Check PH of solution with litmus paper – if solution is acidic add additional
NaCO3 until solution is neutral or alkaline.
Turn on tap into the sink to maximum flow – remove the drain plug. Gently
pour the neutralised solution into the sink with the tap continuously running.
Continue to flush the sink for a minimum of 15 minutes to ensure that the
neutralised solution is flushed with a minimum of 200litres of water.
Triple rinse the 20l plastic bucket.
Replace the NaCO3 before proceeding with electropolishing operations.
7.
General Emergency procedures
7.1
Raise the Alarm
7.1.1
Ensure the immediate safety of anyone within the vicinity of the spill.
7.1.2
Evacuate the immediate area.
7.1.3
Report the spill: To Security (on extension 333 or by using a RED emergency phone) and
to your supervisor, or Safety Officer, or OHSE.
OR
If you cannot contact any of these, break the nearest “Break Glass Alarm”, which
automatically notifies the Fire Brigade, Security and ECO – Turn off mobile phones in
the event of a gas leak.
7.2
Isolate Hazard
7.2.1
Anybody who has been exposed must, if safe to do so, be moved to a safe
decontamination area. The treatment of serious injury must take precedence over
decontamination and containment.
NOTE: If unsure of the hazards presented and associated risk to health and safety, consult
with your supervisor, or Safety Officer, or OHSE prior to taking any action.
7.2.2
Restrict unnecessary movement into and through the area to avoid spreading
contamination. Isolate the affected area at a safe distance by erecting a temporary
barricade and placing suitable warning signs.
7.3
Clean-Up
7.3.1
Do not re-enter the area until it has been decontaminated by personnel trained specifically
in chemical safety. [Note: For any clean-up activities there must be a minimum of two
people].
7.4
Evacuate
7.4.1
Evacuate the building as instructed to do so by the emergency personnel.
7.4.2
Walk quickly and calmly to the assembly area advised by the emergency personnel.
7.4.3
Remain at the assembly area in groups.
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7.4.4
In the case of a fire every effort must be made to prevent undue spreading of
contamination. However, fire fighting must take precedence over the control of
contamination.
7.4.5
Do not switch on any electrical equipment, light switches, etc, as these may cause a spark
and become an ignition source.
8.
Spill Cleanup
8.1
Refer to Item 7. General Emergency Procedures.
8.2
Assess the severity of the spill from a safe distance – only proceed with the cleanup if
safe to do so, if available spill kit (two 20l plastic drums approximately half full with
sand in the foyer) is adequate, if appropriate PPE is available and if trained to do so.
Refer to General Emergency Procedures if it is not considered safe to proceed with a spill
cleanup.
DO NOT ENTER A LABORATORY where visible fumes are present – full breathing
apparatus will be required in these cases.
Warn others to stay at a safe distance.
8.3
Isolate the spill and area - use tape, witches hats, and danger signs to isolate a sensible
area around the spill.
8.4
Obtain assistance. Note: Two people must be present at all times during a spill cleanup.
8.5
Consult the relevant MSDS’s (identify main hazards and appropriate precautions for
clean up)
8.6
Choose and don appropriate PPE (liquid spills require organic vapour mask and solid
spills require dust mask. Acids and bases require butyl rubber gloves, phenol require
nitrile rubber gloves and solvents require nitrile rubber gloves. Those members not
directly handling the chemical substance may use natural rubber gloves.).
8.7
Turn on ventilation if needed.
8.8
Perform clean up – form a barrier with sand around the perimeter of the spill, then cover
with sand (employ actions that limit the spread of the chemical – eg. wiping in towards
the centre of the spill)
8.9
Transfer sand and spill material back into the 20L plastic drums and seal.
8.10
Dispose of waste via Chemsal in accordance with Item 6.
8.11
Wash site of spillage thoroughly with water – before proceeding determine if water can
be run to waste or disposed of via Chemsal.
8.12
Triple rinse containers prior to putting back in service.
8.13
Replace sand used in the cleanup prior to resuming work with electropolishing solutions.
9.
Explosion
9.1
Refer to Item 7. General Emergency Procedures.
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9.2
Isolate the area at a safe distance – erect warning signs, etc.
9.3
Warn others to stay at a safe distance.
9.4
Contact Security on 333.
9.5
Do not enter any area following an explosion – leave this for the MMFESB who have the
appropriate training and equipment.
10.
After Hours Access Procedures
10.1
Refer to Departmental After Hours Access Procedures.
10.2
Sign the log book located in the central foyer outside Room G14.
10.3
On arrival contact Security on Ext. 53059. Report who you are, your location and your
expected departure time. Immediately prior to leaving contact security to advise of your
departure.
10.4
Two people must be present at all times if electropolishing is to be performed outside
normal working hours – defined as 8:30am to 5:30pm.
10.5
Refer also to the Monash University “OHS Policy for work and study during times when
emergency response is limited”. A copy is available on the OHSE web site at:
Prepared by: … ………..Date: ……………………Signed:…………………
March 2010