1. In this Schedule—
“contact current (IC)” is the current created when a person comes into contact with an object in an electromagnetic field, expressed in ampères (A);
“external electric field strength (E)” is a vector quantity corresponding to the force exerted on a charged particle in the environment, irrespective of its motion in space, expressed in volts per metre (Vm-1);
“internal electric field strength (E)” is a vector quantity corresponding to the force exerted on a charged particle inside the human body, irrespective of its motion in space, expressed in volts per metre (Vm-1);
“limb current (IL)” is the current induced in the limbs of a person exposed to electromagnetic fields in the frequency range from 10 MHz to 110 MHz, expressed in ampères (A);
“magnetic flux density (B)” is a vector quantity resulting in a force that acts on moving charges, expressed in tesla (T);
“power density (S)” is the radiant power incident perpendicular to a surface, divided by the area of the surface, expressed in watts per square metre (Wm–2);
“specific energy absorption (SA)” is the energy absorbed per unit mass of biological tissue, expressed in joules per kilogram (Jkg–1);
“specific energy absorption rate (SAR)” is the rate at which energy is absorbed per unit mass of body tissue, expressed in watts per kilogram (Wkg–1).
2. The ALs and ELVs are set out in tables and grouped according to their potential effects, being—
(a)thermal effects, related to the heating of tissue due to its absorption of electromagnetic fields; and
(b)non-thermal effects, related to the stimulation of nerves or sensory organs due to the presence of electromagnetic fields.
3. The Low ALs in Table AL1 of Part 2, and the ALs in Part 3, specify the electromagnetic field levels above which specific indirect effects may occur.
4. The remaining ALs in Part 2 are defined physical quantities related to the direct biophysical effects of exposure to electromagnetic fields. Employers may, as part of their exposure assessment, assess electromagnetic field levels against these ALs. Each AL table states which ELV or ELVs will be complied with if electromagnetic field levels at a particular frequency do not exceed that AL. Exposures to electromagnetic field levels in excess of the AL may still be below the relevant ELV but the employer will have to undertake further assessment to determine this under regulation 5.
5. Except where otherwise indicated—
(a)“f” is the frequency expressed in hertz;
(b)the ALs and ELVs relate to exposure in any part of the body; and
(c)notes to the tables apply only to the table under which they appear.
6. The applicable safety measures referred to in regulation 4(2) are those required by the notes to the table or tables containing the sensory effect ELV which is to be exceeded, being—
(a)the note to Table ELV1; and
(b)note 2 to Tables ELV3 and ELV5.