The RoHS Directive refers to Directive 2002/95/EC of the European Parliament and of the Council of 27 January 2003 on the restriction of the use of certain hazardous substances in electrical and electronic equipment.
This directive prohibited the sale of any new electrical and electronic equipment containing more than the allowable levels* of lead, mercury, cadmium, hexavalent chromium, PBB (polybrominated biphenyl), or PBDE (polybrominated diphenyl ether) after July 1, 2006.

The purpose of this Directive is to approximate the laws of the Member States on the restrictions of the use of hazardous substances in electrical and electronic equipment and to contribute to the protection of human health and the environmentally sound recovery and disposal of waste electrical and electronic equipment.

The applicable products are those in categories 1 to 7 and category 10 below. As of February 2006, medical equipment (category 8) and monitoring and control equipment (category 9) are exempt. Spare parts for repairing electrical and electronic equipment, and reused components, sold prior to July 1, 2006, are also exempt.

The products that IAB handles include equipment such as PCB inspection devices, which are finished products, and sensors and other equipment, which are assembled into other electrical and electronic equipment for use. Our finished products fall into category 9, so they are exempt from the RoHS Directive as of April 2007. Products such as sensors that are assembled into other equipment for use do not fall into any of the categories, so they are essentially exempt from the RoHS Directive, but care must be taken because they may become subject to the RoHS Directive depending on the category of the finished product into which they are assembled.

The following are recognized as exempted applications.
(Published as 2002/95/EC in the Official Journal dated February 13, 2003; 2005/717/EC in the Official Journal dated October 15, 2005; 2005/747/EC in the Official Journal dated October 25, 2005; 2006/310/EC in the Official Journal dated April 28, 2006; 2006/690/EC, 2006/691/EC, 2006/692/EC in the Official Journal dated October 14, 2006; with revisions and additions presently under consideration.)
29 Items are permitted at this present moment(April 2007), and listed below are the major items. For details, please confirm the Official journal.

The maximum allowable concentrations are as shown below, regardless of whether or not the substances have been intentionally added. (2005/618/EC in the Official Journal dated August 18, 2005)

These maximum allowable concentrations are weight ratios for homogeneous material. Homogeneous material refers to a material that cannot be mechanically separated into constituent materials.

A “decision tree” that could be used by producers to decide whether or not a product might come within the scope of the RoHS Regulations.
Quote from DTI's RoHS regulations: Government guidance notes 2007.

While the products handled by the Company are exempt from the RoHS Directive, we have set the goal of eliminating the 6 RoHS regulated substances from all OMRON brand (the Company) products by the end of March 2006, and are voluntarily proceeding to prohibit the use of the 6 regulated substances in all products.

However, in addition to the exempted applications recognized by the RoHS Directive, The Company also considers the following products to be exceptions.

Because we need to gain the cooperation of all our global suppliers in order to eliminate the 6 RoHS regulated substances, we will perform the following activities while working to gain this cooperation.

The following activities will also be conducted inside OMRON:

From the viewpoint of reliability and productivity, we have selected lead-free Sn-Ag-Cu or Sn-Cu solder materials, or Sn-Ag-Cu or Sn-Cu solder materials to which trace elements have been added.

Because the melting temperature of lead-free solder is approximately 30 degrees higher than conventionally used eutectic solder, we have installed devices that exhibit little temperature fluctuation in reflow and flow processes. We are also using special soldering irons for manual soldering, and have organized process control standards and work standards for each device used.

In determining the plating to be used for relay, switch, and connector terminals, we consider the viewpoints of solder wettability, whisker prevention, long-term connection reliability, heat resistance, etc., and select either Sn-Cu, pure Sn, Sn reflow, or gold plating to match the functions and performance of each product.

While conducting the above-described activities and working to gain the cooperation of our suppliers in order to eliminate the 6 RoHS regulated substances, we are indicating compliance by using the RoHS compliance mark based on the following considerations.

Products (those in which regulated substances have been eliminated within processing and in PCB-mounted electronic components) in which the 6 RoHS regulated substances have been eliminated: The RoHS compliance mark is indicated on the package.

Products belonging to the previously described exceptions, or products in which the 6 RoHS regulated substances have been eliminated in processing, but not in the PCB-mounted electronic components: No RoHS compliance mark is indicated on the package.

For products in which the PCB-mounted electronic components are not RoHS-compliant, the component manufacturer is requested to take the necessary steps for compliance, and once compliance is achieved, the products are manufactured as RoHS-compliant products.

The following criteria are used to determine whether the 6 RoHS regulated substances have been sufficiently eliminated.