Health and Safety Executive

OCE Mixing of drilling muds (sack room) Offshore COSHH Control approach 2 essentials Engineering control

This information will help offshore What this sheet covers dutyholders (owners, operators and This sheet describes good practice for control of exposure to chemicals contractors) to comply with the Control when mixing drilling mud. It covers the key points you need to follow to of Substances Hazardous to Health help reduce exposure to an acceptable level, as part of your COSHH Regulations 2002 (COSHH), as amended, to assessment. protect workers’ health.

This guidance consolidates good control practice and reinforces existing knowledge with additional information.

It will help you carry out COSHH assessments, review existing assessments, deliver training and in supervising activities involving substances hazardous to health.

It is aimed at staff whose responsibilities include the management of substances hazardous to health on offshore installations (eg occupational health specialists, COSHH assessors, supervisors etc). It is also useful for trade union and Hazard employee safety representatives. 3 Drilling muds contain a wide range of substances including Following this guidance is not compulsory base fluids (eg mineral oils/ and you are free to take other action. But calcium chloride brine), weighting if you do follow this guidance, you will agents (eg barite), viscosifers normally be doing enough to comply with (eg bentonite), surfactants (eg the law. Health and safety inspectors seek imidazolines) and biocides (eg to secure compliance with the law and may glutaraldehyde). They can also refer to this guidance as illustrating good contain contaminants from practice. formations (eg oil, condensate and H2S). Also see essential information on the back of the sheet. 3 Health effects include dermatitis, respiratory irritation, narcosis and cancer.

Access 3 Restrict access to authorised personnel.

Equipment and procedures Substitution 3 Use water-based muds where possible: otherwise use low toxicity base oil and low-dust solids.

Control equipment 3 Use bulk transfer methods where possible. Provide enclosed weighing hoppers for bulk solids. 3 Provide an extracted sack-opening machine with integrated sack disposal. 3 Otherwise enclose the hopper as much as possible and provide local exhaust ventilation. Permit access for careful opening and emptying of sacks. 3 Ensure solids are poured gently into the hopper. 3 Ensure empty sacks are rolled up in the extracted zone and put it in a polythene sack. 3 Fit an airflow indicator to show that extraction is working properly. 3 Discharge extracted air to a safe place. 3 Provide a venturi system or metered pumping for bulk liquids. Caution: Sacks often have dust on the surface

Personal protective equipment (PPE) – see OCM3 3 Ensure that all items of PPE are compatible. Respiratory protective equipment (RPE) – see OCM4 3 Where effective LEV is not provided for sack handling, provide CE-marked RPE with an assigned protection factor of at least 20. 3 Air-fed RPE with an assigned protection factor of at least 40 should be provided for emptying dust collectors.

Other protective equipment 3 Provide disposable (type 5) coveralls. 3 Provide non-slip rubber boots. 3 Provide clean chemical-resistant gloves, eg nitrile, and new gloves when these are damaged.

Maintenance, examination and testing Checking and maintenance 3 Check for signs of damage at the start of every shift. 3 At least once a week, check that airflow indicators work properly. 3 Keep this information in your testing logbook. 3 Check dust collectors and empty before they are too full. 3 Lock off extraction systems before emptying dust collectors. Examination and testing 3 Extraction systems require statutory ‘thorough examination and testing’ (TExT). 3 Get a competent ventilation engineer to perform the TExT at least once every 14 months (see HSE publication HSG258). 3 Carry out all actions arising from the TExT.

RPE Employee checklist 3 Examine and test RPE thoroughly at least monthly and for infrequently Is the equipment in good used RPE at least three monthly. Replace worn parts. condition and working properly? Records 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 Prove that you are using the right level and type of RPE – use Clean up leaks and spills monitoring records or carry out personal air monitoring. immediately.

Cleaning and housekeeping If you find any problem, 3 Clean the area at least once a week, or after each batch mixed. get it fixed. Don’t just 3 Clear up spills immediately. Use protective gloves. You may also need carry on working. RPE. Co-operate with health 3 Use a class H vacuum cleaner or use wet methods for cleaning. surveillance. Caution: Do not use a brush or compressed air for cleaning. Never use Use, look after and store compressed air to remove dust from clothing. your PPE in accordance with instructions. 3 Label bags of dirty clothing to warn the laundry about the hazard. Wash hands before Waste eating, drinking or using 3 For disposal off-installation, provide the operator of the disposal vessel the lavatory. with suitable information.

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 Instruct workers in how to clean their skin effectively. 3 Tell workers to wash hands before every break. 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.

Caution: ‘Barrier creams’ or ‘liquid gloves’ do not provide a full barrier.

Health surveillance 3 Conduct low-level health surveillance for dermatitis involving skin checks by suitably trained responsible person.

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 Explain the early signs of dermatitis. 3 Training includes toolbox talks on: n how to use equipment properly;

n how to check that extraction is working properly;

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.

Essential information Other hazards OCE0 Advice for managers n Musculoskeletal disorders –

OCM2 Local exhaust ventilation (LEV) manual handling awkward OCM3 Personal protective equipment (PPE) heavy items in restricted OCM4 Respiratory protective equipment (RPE) places OCM7 Health surveillance n Substances harmful to the

OCM8 Storing chemicals marine environment

Further information 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

Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV) HSG258 HSE Books 2008 ISBN 978 0 7176 6298 2 www.hse.gov.uk/pubns/books/ hsg258.htm

BS EN 60335-2-69:2003 Class H vacuum cleaner

BS EN 60335-2-69:2009 Household and similar electrical appliances. Safety. Particular requirements for wet and dry vacuum cleaners, including power brush, for commercial use

Workplace exposure limits EH40 www.hse.gov.uk/coshh/table1.pdf

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