Substance Prohibition
A group of four specific plasticising chemicals is restricted to a maximum concentration of one-tenth of a percent by weight in homogeneous electronic materials. In PCB fabrication and assembly, rohs restricted phthalates must be monitored in flexible cables, vinyl insulation, and synthetic rubbers used throughout the board. These four compounds, comprising bis(2-ethylhexyl) phthalate, butyl benzyl phthalate, dibutyl phthalate, and diisobutyl phthalate, are banned because they can leach out of electronics during their lifecycle and harm the environment.
Material Compliance
Manufacturers must secure declarations of conformity from their supply chains to ensure that incoming plastic parts and cables meet the specified thresholds. High-pressure liquid chromatography or gas chromatography coupled with mass spectrometry is used to verify compliance when a risk assessment identifies high-risk materials. Because board assemblies contain many small, distinct parts, the limit applies to each homogeneous material individually rather than to the entire finished product as a single unit.
Consequently, a single non-compliant plastic spacer or insulated wire on a populated board will cause the entire printed circuit board assembly to fail the audit.
Exemption Boundary
The regulatory restriction applies to all electronic and electrical equipment entering the European market unless a specific, time-limited exemption has been granted for medical or industrial monitoring equipment. It ceases to apply once the materials are used in aerospace or military applications that remain outside the scope of the general environmental directive.
