Mercury in medical devices

Current Status:
Using mercury safely
The Health and Safety Executive (HSE) first issued the Regulations for the Control of Substances Hazardous to Health (COSHH) in 1988. This provides a comprehensive and systematic approach to the control of hazardous substances, such as mercury, substituting other less hazardous chemicals where possible. However, where it is not possible to substitute away from mercury, the above devices can still be used provided staff are trained to ensure safe handling during normal use and in the event of a mercury spillage. There should be local procedures for dealing with mercury spillage and disposal.

Blood pressure measurement devices
MHRA has issued a Device Bulletin to inform the NHS of the position regarding mercury and to give guidance to those wishing to purchase alternative blood pressure measurement devices. Device Bulletin MDA DB2000(03) Blood Pressure Measurement Devices - Mercury and Non-Mercury, July 2000.

We are aware of the many issues surrounding the use of mercury and the difficulty in obtaining accurate, reliable and cost effective alternative devices. The Device Bulletin provides users and purchasers with information to enable them to decide whether to replace their mercury devices and to offer guidance on the selection process to ensure an appropriate product is obtained.

Since the publication of this Device Bulletin several new products have appeared on the market. There are electronic pressure gauges with a digital seven segment or circular bar graph display, that require the user to observe the Korotkoff sounds with a stethoscope. There are also automated devices that indicate when the patient has an arrhythmia.

This bulletin was updated in 2006.
› DB 2006(03) Blood Pressure Measurement Devices

A top tips leaflet on blood pressure monitors and sphygmomanometers has been published in MDA/2006/037.

Committee on Blood Pressure Monitoring in Clinical Practice
A group was set up, whose remit is to evaluate whether mercury sphygmomanometers should continue to be used or removed from the clinical environment; and to consider the alternatives to mercury devices and the evidence regarding their accuracy.  The report has been published. A summary was distributed via MDA/2005/069.

Dental amalgam
At present, there are no plans to further restrict the addition of mercury to dental amalgam. Current advice is that it may be prudent not to remove or place fillings during pregnancy where clinically reasonable (although there is no evidence to suggest it is harmful). There are a few cases of allergy and hypersensitivity, and alternatives should then be used. At present, dental amalgam provides a high quality and effective restoration, with many of the alternatives not as effective.

The safety of dental amalgams has been reviewed extensively over the past 10 years, both nationally and internationally, concluding dental amalgam is safe to use. Please see the summary of evidence.

The Future:
In January 2005 the EU adopted the ‘Community Strategy Concerning Mercury’ and its accompanying ‘Extended Impact Assessment’. They are available at http://europa.eu.int/comm/environment/chemicals/mercury/ (external site). The Strategy aims to protect human health and the environment from all releases of mercury, based on a life cycle approach and highlighting areas of concern and needs for action within and outside the European Union.

Medical Devices
Sphygmomanometers and fever thermometers
Council Directive 76/769/EEC (external link) has been published. The scope includes a restriction of the marketing of mercury containing fever thermometers to both consumers and healthcare professionals and mercury sphygmomanometers to consumers only. It will not relate to the use of such products, only the sale. This Directive should be transposed into UK law by 3/10/2008, coming into effect by 3/4/2009.

The sale of mercury sphygmomanometers to healthcare professionals is currently exempted. However, the Commission is required to review this exemption by 3/10/2009.

For queries on sphygmomanometers and fever thermometers please contact:
Geoff Smith, Senior Medical Device Specialist
Device Technology and Safety
Tel: 020 7084 3198
Fax: 020 7084 3209
E-mail: geoff.smith@mhra.gsi.gov.uk

Dental Amalgam
In ‘A Community Strategy concerning Mercury’, Action 6 states that ‘In the short term the Commission will ask the Medical Devices Expert Group to consider the use of mercury in dental amalgam, and will seek an opinion from the Scientific Committee on Health and Environmental Risks, with a view to considering whether additional regulatory measures are appropriate’.

MHRA and The Department of Health (UK) will continue to monitor the international literature for any reports that may indicate harmful side effects to health from dental mercury amalgam fillings. This information will be assessed against the benefit gained from the use of dental amalgam.

For queries on dental amalgam please contact:
Ian Smith
Biosciences and Implants
Tel: 020 7084 3306
Fax: 020 7084 3106
E-mail: ian.smith@mhra.gsi.gov.uk