Check Your Cable Markings

Electrical contractors, specifiers and electricians who purchase and install cable have a responsibility to ensure that the cable they specify meets British and European standards to guarantee its safe use within its environment. In some cases however, markings on the cable sheath can be misleading, or even make false claims of compliance with a particular standard.

The British Approvals Service for Cables (BASEC) is a recognised sign of assurance of independent cable testing and approval. The organisation rigorously tests electrical cables, data and signal cables and ancillary products to meet appropriate British, European and international standards through detailed examination of manufacturers' production processes and controls, and regular product testing.

Jeremy Hodge, chief executive at BASEC explained: “It is important that specifiers know what markings to look for on cable sheaths, not just on the packaging. Always look for a manufacturer’s mark that you recognise, which can be helpful in tracing a cable through the supply chain, the cable specification such as a BS number, and always check for a BASEC or HAR stamp. Only cable marked with the BASEC name has been BASEC approved.

“Some non-approved cables claim to comply with a British, European or international standards, but if BASEC finds cable with serious faults we will issue a public warning.  Problems could include excessive or poor conductor resistance, which could lead to overheating in use or electric shock, or the sheath could insulation crack or disintegrate when subjected to different temperatures.

“If users find a cable without a manufacturer’s mark, or without the specification or standard number, these should be rejected; likewise if a cable is marked with an ambiguous specification such as a CMA or catalogue code, or even completely unmarked.”

It is a common misunderstanding that a cable is compliant with standards or even BASEC approved just because the supplier claims that it has been produced to a particular standard, by printing the standard number on the cable. Cable marked with only a standard number should be treated with caution, as it is probable that nobody independent of the manufacturer has examined that cable.

Further information and assistance is available at,, or contact BASEC directly on 01908 267300.


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