The Commission recommended to the EU's 27 nations that they push back the deadline for four years until April 30, 2012, so that its impact on exposure to Magnetic Resonance Imaging (MRI) could be taken into account.
MRI is the leading technique for detecting brain tumours and many other serious conditions. It allows doctors to help some eight million patients each year.
A study published in Britain in June suggested that the planned measures could have an impact on the use of MRI technology.
"The Commission remains committed to the protection of the health and safety of workers," said EU social affairs commissioner Vladimir Spidla.
"However, it was never the intention of this directive to impede the practice of MRI."
Electric and magnetic fields exist wherever electric current flows: from power lines and cables to residential wiring and electrical appliances.
Their effects on human health are not clearly understood but they have been linked, when the exposure is long term, to certain cancers including leukaemia, according to the World Health Organisation.