OCE14 - Breaking containment – mercury

Health and Safety Executive

OCE Breaking containment – mercury Offshore COSHH Control approach R essentials Respiratory protective equipment

This information will help offshore What this sheet covers dutyholders (owners, operators and This sheet describes good practice where mercury (metal, inorganic or contractors) to comply with the Control organic) occurs naturally in crude, condensate or gas streams during of Substances Hazardous to Health production operations. It covers the key points you need to follow to Regulations 2002 (COSHH), as amended, to help reduce exposure to an acceptable level, as part of your COSHH protect workers’ health. assessment.

This guidance consolidates good control Hazards practice and reinforces existing knowledge 3 Mercury vapour can condense from gas streams and accumulate on with additional information. cold surfaces. Steel surfaces can collect mercury. Mercury vaporises easily. It will help you carry out COSHH 3 Health risks include damage to the nervous system and kidneys. assessments, review existing assessments, 3 See ‘Further information’ for where to find more about exposure limits. deliver training and in supervising activities 3 The EU indicative occupational exposure limit value (IOELV) for mercury involving substances hazardous to health. and its inorganic compounds is set at 0.02 mg/m3 (8-hour time- weighted average (TWA)). It is aimed at staff whose responsibilities 3 OSHA and NIOSH have set an exposure limit of 0.01 mg/m3 (8-hour include the management of substances TWA) for organic mercury compounds. hazardous to health on offshore 3 The UK biological monitoring guidance value for mercury in urine is installations (eg occupational health 20 micro mol mercury per mol creatinine. specialists, COSHH assessors, supervisors etc). It is also useful for trade union and Access employee safety representatives. 3 Erect barriers and notices. 3 See sheet OCM1 if work is in a confined space. Following this guidance is not compulsory and you are free to take other action. But Equipment and procedures if you do follow this guidance, you will Design normally be doing enough to comply with the law. Health and safety inspectors seek 3 Where mercury is known or suspected, design vessels and pipework with mercury traps. to secure compliance with the law and may refer to this guidance as illustrating good Planning practice. 3 Keep a record/log of known mercury areas. Also see essential information on the back 3 Label plant and equipment where mercury is known to collect. of the sheet. 3 Define the isolation standards and routines for draining, purging and venting. 3 Ensure that pipework/hoses used for flushing is made of suitable material to transport.

Breaking containment – mercury OCE14 Respiratory protective equipment

Control equipment 3 Provide enough fresh air to dilute and remove air contaminants. 3 Provide monitoring by mercury meter. 3 Respiratory protective equipment is normally required. Control procedures 3 Isolate the line for safe opening. 3 Drain, purge and flush the system. Test for mercury. 3 Prove it is free of gas. If necessary, have the authorised tester perform the gas test. 3 Check filters and drain traps for signs of mercury. 3 Clear up mercury residues with a spill kit. Mercury collection 3 Collect mercury droplets, eg with a vacuum cleaner having a mercury vapour filter. 3 Remove mercury on contaminated surfaces by adding sulphur and leaving overnight to form an amalgam or use a commercially available mercury spill kit.

Personal protective equipment (PPE) – see OCM3 3 Respiratory protective equipment (RPE) is needed where monitoring shows mercury is present. 3 Provide CE-marked RPE with an assigned protection factor of at least 10 for mercury. 3 Breathing apparatus (BA) or air-fed RPE, CE marked with an assigned protection factor of at least 40, is likely to be needed for confined space work. 3 Filtering RPE must be fitted with mercury and hydrocarbon vapour cartridges.

Other protective equipment 3 Provide disposable coveralls (type 4). 3 Use rubber wellington boots for ease of cleaning. 3 Provide clean chemical-resistant gloves, eg nitrile, and new gloves when these are damaged. 3 Discard gloves at the end of the shift. Maintenance, examination and testing Checking and maintenance 3 Make and follow schedules for preventative maintenance of plant and monitoring equipment. 3 Before use, check the air lines for supplied-air BA. 3 Check for signs of damage to control equipment before starting work. Examination and testing 3 Calibrate a mercury meter at least once a month and check that it works properly before every use.

Breaking containment – mercury OCE14 Respiratory protective equipment

RPE Employee checklist 3 Check the airflow and air quality to air-fed RPE at least monthly and Are you sure about safe infrequently used RPE at least three monthly, or before use. Check work procedures? in-line filters. Is the equipment in good 3 Examine and test RPE thoroughly at least monthly and infrequently condition and working used RPE at least three monthly. Replace worn parts. properly? 3 Ensure that breathable air compressors take in clean air. Is your respirator working properly? Check it every Records time. 3 Keep records of all examinations and tests for at least five years. Look for signs of leaks, wear and damage before Exposure monitoring every job. 3 Monitor mercury in the air by meter. Do you have a spill clean- 3 Prove that you are using the right level and type of RPE – use up kit handy? monitoring records or carry out personal monitoring. If you find any problem, 3 Personal air monitoring may be appropriate for major work involving get it fixed. Don’t just exposure to mercury. carry on working. 3 Use biological monitoring for workers potentially exposed to mercury. Discard single-use gloves every time you take them Cleaning and housekeeping off. Throw away other 3 Keep a small mercury spill clean-up kit nearby during the task. The kit gloves at the end of the should also contain PPE. shift. 3 Label bags of dirty clothing to warn the laundry about the hazard. Wash before eating, drinking or using the Waste lavatory. 3 Residues are ‘hazardous waste’. Label containers clearly – include a UN number where appropriate. Store and dispose of waste safely.

Personal decontamination and skin care 3 Provide warm water, mild skin cleansers, nailbrushes, and soft paper, fabric towels or hot air for drying. Avoid abrasive cleansers. 3 Provide pre-work skin creams, which will make it easier to wash dirt from the skin, and after-work creams to replace skin oils. 3 Provide a spillage clean-up kit. 3 Provide eyewash equipment and an emergency shower close to the work site.

Training and supervision 3 Provide supervision – ensure that safe work procedures are followed. 3 Tell workers, including maintenance workers, what the hazards and risks are. 3 Training includes toolbox talks on: n following safe working procedures;

n how to use equipment properly;

n how to use RPE and check that it is working;

n how to clean up spills correctly; and

n what to do if something goes wrong.

3 Involve managers and supervisors in health and safety training.

Breaking containment - mercury OCE14 Respiratory protective equipment

Essential information Other hazards OCE0 Advice for managers n NORM (naturally occurring

OCM1 Confined spaces radioactive material) OCM3 Personal protective equipment (PPE) n Substances harmful to the

OCM4 Respiratory protective equipment (RPE) marine environment OCM6 Exposure monitoring Further information OCM7 Health surveillance Mercury and its inorganic OCE6 if hydrogen sulphide is present divalent compounds in air: ORE1 if NORM is present Laboratory method using Hydrar diffusive badges or pumped sorbent tubes, acid dissolution and analysis by cold vapour atomic absorption spectrometry or cold vapour atomic fluorescence spectrometry MDHS16/2 (Second edition) HSE Books 2002 www.hse.gov.uk/pubns/mdhs/

Respiratory protective equipment at work: A practical guide HSG53 (Third edition) HSE Books 2005 ISBN 978 0 7176 2904 6 www.hse.gov.uk/pubns/books/ hsg53.htm

You can find the full Offshore COSHH essentials series at www.hse.gov.uk/coshh/index.htm

This guidance was developed by representatives from the UK offshore oil and gas industry and trade unions, with HSE.

© Crown copyright 2011 Published by the Health and Safety Executive 03/11