This glossary provides more details of some of the terms and acronyms we use on our website. If you find any that you do not recognise and they are missing from this glossary, please let us know.
ADR - American Depositary receipts, negotiable certificates representing holdings in ADSs.
ADS - American Depositary Shares, each which represents the right to receive five ordinary shares.
BITC - Business in the Community. A UK based organisation of over 700 of the top UK companies committed to improving their positive impact on society.
BLIHR - Business Leaders Initiative on Human Rights, a business-led group chaired by Mary Robinson, the former United Nations High Commissioner on Human Rights
Category 1 environmental incidents - Incidents that may have resulted in environmental damage. Part of our internal classification of incidents.
CO2 - Carbon dioxide. A greenhouse gas that is both naturally occurring and generated through the combustion of fossil fuels or organic material.
CO2 equivalent - The equivalent amount of carbon dioxide required to create the same level of global warming as another greenhouse gas (e.g. 1 tonne of sulphur hexaflouride is equivalent to 23,900 tonnes of carbon dioxide).
Controlled gas escape - A gas escape where the leak can be controlled at the meter.
Decatherm - An amount of energy equal to 1 million British thermal units (BTUs), equivalent to approximately 293 kWh.
DEFRA - Department of the Environment, Food and Rural Affairs. UK Government department.
EMF - The electric and magnetic fields produced by all electrical equipment and appliances.
Employee Engagement Index - A key performance indicator, based on the percentage of favourable responses to certain indicator questions repeated in each employee engagement survey, which provides a measure of how employees think, feel and act in relation to National Grid.
EMS - Environmental Management System (e.g. ISO14001).
EPA - Environmental Protection Agency. US environmental regulator.
Framework for Responsible Business - Defines the principles by which we manage the business, sets the context for corporate governance, and helps us take account of economic, environmental and social factors in our decisions.
Greenhouse gas - A gas such as CO2, methane or SF6 that is known or is likely to result in changes to the earth's atmospheric temperature.
GRI - Global Reporting Initiative: a multi-stakeholder process and independent institution whose mission is to develop and disseminate globally applicable Sustainability Reporting Guidelines. These Guidelines are for voluntary use by organisations for reporting on the economic, environmental, and social dimensions of their activities, products, and services.
HSE - Health and Safety Executive. UK regulator with principal aim to ensure that risks to people's health and safety from work activities are properly controlled.
IFRS - International Financial Reporting Standard
Injuries to the public - major injuries, comprising fatalities and other injuries that require the person to receive hospital treatment or, in the UK, injuries reported under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations.
ISO 14001 - International Standards Organisation's standard for environmental management systems.
LNG - Liquefied natural gas
Lost time injury frequency rate - The number of lost time injuries an employee is statistically likely to receive during his or her working life (measured as injuries per 100,000 hours worked).
LTI, Lost Time Injury or Incident - An incident arising out of National Grid’s operations which leads to an injury where the employee or contractor normally has time off the following day or shift following the incident. It relates to one specific (acute) identifiable incident which arises as a result of National Grid’s premises, plant or activities, which was reported to the supervisor at the time and was subject to appropriate investigation.
MCM - Million standard cubic metres, equivalent to approximately 35.3 million standard cubic feet.
MGP - Manufactured Gas Plants - sites where, historically, gas was manufactured from coal.
mte CO2 - million tonnes equivalent; Measure of greenhouse gas emissions related to the impact of carbon dioxide
MW - Megawatt (measure of energy).
MWhrs - Mega watt hours (measure of energy supply).
NGO - Non-governmental organisation.
Nox - Nitrogen Oxide. Gas associated with acid rain and ground level ozone.
NRPB - National Radiological Protection Board. The UK Government's adviser on the protection from radiation hazards either of the community as a whole or of particular sections of the community.
OFGEM - Office of the Gas and Electricity Markets. The regulator for Britain's gas and electricity industries.
OSHA - The Occupational Safety & Health Administration, the main federal agency charged with the enforcement of safety and health legislation in the US.
Pylons - UK equivalent of towers.
Risk & Responsibility Committee - Board committee with responsibility for reviewing the non-financial risks, strategies, policies, management, targets and performance of the Company, and where appropriate our suppliers and contractors, in the areas of occupational and public safety, occupational health, environment, equality and diversity, human rights, business ethics and role in society.
Schedule 9 - Schedule to the Electricity Act 1989 under which National Grid UK is required to set out how it addresses the amenity aspects of its operations.
SCM - Standard cubic metre, a quantity of gas which at 15°C and atmospheric pressure (1.013 bar) occupies the volume of 1 cubic metre
SF6 - Sulphur hexafluoride. Used as an insulator in electrical equipment. Also a greenhouse gas.
Sharesave - The equity participation arrangement for National Grid employees in the UK.
Sox - Sulphur Oxide
Towers - US equivalent of pylons.
TW or TWh - Terawatt or Terawatt hours (measure of energy)
UDHR - Universal Declaration of Human Rights.
UN - United Nations.
Uncontrolled gas escape - A gas escape where the leak cannot be controlled at the meter