Work Activity:
Charging or Decanting Ammonia Refrigerant /
Thornliebank Industrial Estate Glasgow G46 8JW
Tel: 0141 638 7916 Fax: 0141 638 8111
Site/Location:
Various site locations
Those at Risk / Y/N / Comments - enter names or general groups
Star Employees:
Other workers:
General Public: / Y
Y
N / Star Engineers and their assistants
Subcontractors and other trades working in the area
Comments: No one may decant refrigerant into a cylinder unless their manager has authorised them to do so and has written (or approved) and issued a method statement in accordance with TB136. When charging a system, it is very easy to overcharge – especially a low-pressure receiver. When decanting a system, it is also very easy to overfill a recovery cylinder. An overfilled refrigerant recovery cylinder presents a serious explosion hazard. It is essential that proper charging and recovery procedures be observed to prevent serious incidents involving injury, loss of life or accidental emission of refrigerant.
Hazards
1. Explosion
2. Toxic
3. Freeze and chemical burns
4. Manual handling injury when moving cylinders or plant
Control Measures (existing or planned)
Control / DetailsPPE: / 1. Safety boots
2. Overalls/protective clothing.
3. Safety goggles to BS EN 166-349B
4. Nitrile impervious gloves to BS EN 374
5. RPE - Full face mask respirator to BS EN 136 fitted with filter cartridge type K2 P3 must be to hand.
Equipment: / 1 Refrigerant recovery pump
2 Scales
3 Suitable charging lines as SS 147
4 Properly identified refrigerant recovery cylinders.
5 Check that a supply of drench water is immediately available for dilution of ammonia splashes to the skin, eyes or clothing. Acceptable supplies in order of preference are (1) Emergency shower or (2) Tap with hose connected or (3) Two 9 litre buckets of fresh water.
6 Log sheet or logbook for recording amount charged or decanted.
Information, Instruction, and Training / 1. Accompaniment is required when charging/decanting ammonia.
2. Instruct the accompanying person what to do in case of emergency - their primary role is to observe from a safe place and to raise the alarm if the engineer conducting the operation gets into difficulty – they are not to attempt a rescue.
3. If re-filling refrigerant cylinders read Star Technical Bulletin No 136 - Re-Filling Refrigerant Cylinders.
4. Wear impervious gloves to prevent refrigerant contacting the hands.
5. Eye protection must be worn when opening any refrigeration system. As a minimum goggles are required.
6. Only Star engineers trained, experienced and in possession of City and Guilds 2077 or 2078 safe handling of ammonia refrigerant certification may charge or decant. They may have an apprentice or assistant helping them or observing the operation
7. Continuously and accurately weigh recovery cylinders during decanting.
8. Continuously supervise charging and decanting operations.
9. Secure cylinders from toppling over
10. Do not trap liquid ammonia between valves
Control Measures Continued
Control / Details11. RPE may be required, therefore, must be to hand. Check that it fits and has been inspected in accordance with SG013.
12. Use mechanical handling equipment or follow good manual handling techniques when moving cylinders
Supervision: / Managers and Supervisors must;
1. Ensure that engineers are appropriately trained in handling ammonia and are in possession of City & Guilds 2077 or 2078.
2. Ensure engineers are trained in the safe use of the RPE.
3. Ensure RPE is subject to recorded monthly maintenance checks in accordance with SG013
4. Write site specific risk assessments for unusual or difficult operations
Environment; / 1. Ensure adequate levels of ventilation.
2. Check emergency exits.
3. Since Ammonia is toxic, charging points should be provided outside the plant room if practicable.
Procedures, documents etc / 1. When charging liquid refrigerant, disconnect hoses slowly in case liquid remains in the hose (frost on the hose may indicate that liquid is still present).
2. Keep an accurate record of the amount of refrigerant charged or decanted.
COSHH: / 1. COSHH 014 or Material Safety Data Sheet for ammonia should be read before beginning the operation.
Communication / 1. Inform the site engineering manager that you will be charging/decanting ammonia and agree exclusion of others from the area.
2. Comply with site rules. Permits may be required
3. Familiarise yourself with the site emergency plan
Emergency action/procedures / In case of a leak.
1. Isolate leak (if possible) following SG020 procedures
2. If isolation is not possible, evacuate area and follow site emergency plan
3. Treatment of injuries should be in accordance with the COSHH or material safety data sheet see COSHH 014 ANHYDROUS AMMONIA
Access: / 1. The engineer should strictly control access to the area.
2. Store cylinders safely - away from traffic routes and heat sources
Waste / 1. Disposal of waste refrigerant is covered by the Environmental Protection Act and the COSHH Regulations. Personnel should ensure that waste refrigerant is disposed of through registered waste operators and obtain waste transfer notes.
2. Do not transport waste (recovered) refrigerant.
Risk Evaluation of Identified Hazards
Likelihood / Highly unlikely = 1 / Unlikely = 2 / Likely = 3Severity / Slightly harmful = 1 / Harmful = 2 / Extremely harmful = 3
(Likelihood x Severity = Risk level) 1 = Trivial, 2 = Tolerable, 3-4 = Moderate, 6 = Substantial, 9 = Intolerable
Identified Hazards (base scores on existing or planned control measures) / Triv' / Tol' / Mod' / Sub' / Int'
1. Explosion 1x3
2. Toxic 1x3
3. Freeze and chemical burns 1x2
4. Manual handling injury when moving cylinders or plant 1x2 / 2
2 / 3
3
Note: Moderate scores; Thought should be given to reducing risk, but the cost and time requirements of prevention
should be carefully considered and limited.
Substantial: Work should not be started until the risk has been reduced, for work in progress, urgent
action is required. Considerable resources may have to be allocated.
Intolerable: If unlimited resources cannot reduce risk, work will be prohibited.
Is risk adequately controlled using the above control measures Y/N / YES / If "NO" State further action requiredState further action required: None
Note : This risk assessment is only valid when all control measures are in place before the work or activity commences and will be reviewed 18/02/12 or earlier if the nature of the work changes or there is a dangerous occurrence.
Assessor: / Chris Haslam / (Sign) / Date 18/02/11References:
BSEN 378 2008
Institute of Refrigeration Codes of Practice (including Minimisation of Refrigerant Emissions).
Star Technical Bulletin No 047 – Correct Refrigerant Charge Level in Low Pressure Receivers.
Star Technical Bulletin No 101 – Ammonia Working Practices
Star Technical Bulletin No 136 - Re-Filling Refrigerant Cylinders
Star Standard Specification No 147 – Ammonia Charging Hose