Thermostats, Switches and relays Print

Electrical and electronic switches, relays and contacts with mercury are normally used in various applications such as:

  • level or “tilt” switches in thermostats, car boot or bonnet lids (lighting), car ride control systems, freezer or washing machine lids, “fall alarms” for the elderly, railway signals, sewer pumps, water pumps, car ABS sensors, light-activators in children's shoes, among others.
  • multiple-pole level switches in excavation machines,
  • mercury-wetted contacts (in electronics),
  • data transmission relays or "reed relays",
  • thermo-switches, among others

Mercury in electrical components has been under substitution in some countries for nearly two decades, and mercury-free substitutes are being used for most or all of these applications. Even though the level of awareness of the mercury-free substitutes is on the rise, the status and extent of substitution varies considerably from one country to another.

Relevant legislation and NGO policy work

In the EU

The European Union has developed and adopted two pieces of legislation regulating the content and disposition of electrical and electronic equipment (EEE); Directive 2002/96/EC (WEEE) mainly ensures separate collection and recycling of EEE, while Directive 2002/95/EC (RoHS) bans the use of certain hazardous chemicals – including mercury or any components containing mercury – in new equipment marketed after 1 July 2006.

The RoHS directive presently covers EEE such as large household appliances, small household appliances, information and communications technology equipment, consumer devices, lighting equipment, electrical and electronic tools, etc.

The directive is currently under revision. The revised RoHS is expected to cover EEE measuring and control devices (including switches, relays) as well as medical devices.

Several countries inEuropehave already taken action to ban or restrict the use of some or all products containing mercury. These countries include:Sweden,Denmark,Netherlands,France,Norway,

From theSwedenandDenmarkexperiences, there have been many detailed studies comparing the cost and functionality of mercury and non-mercury products. All these studies demonstrate the feasibility of banning the sales of most mercury-containing products.

Globally

InCanadaand theUSsome states are much more progressive than others and have already proposed relevant restrictions. In situations where adequate alternatives do not yet exist, most of these countries allow specific exemptions for specialized uses.

For the US information is provided at http://www.epa.gov/hg/regs.htm, at http://www.epa.gov/hg/consumer.htm#bat and at http://www.newmoa.org/prevention/mercury/modelleg.cfm