In the complex landscape of product compliance, the CE mark stands as a symbol of adherence to European Union (EU) regulations, ensuring that a product meets the necessary safety, health, and environmental protection standards. It indicates that the product has undergone thorough assessment and testing to guarantee its conformity with safety and performance standards. However, a common misconception exists regarding the combination of two individual devices, each bearing its own CE mark.

CE Plus CE Does Not Equal CE

Unfortunately, the union of two CE-marked devices does not inherently result in compliance for the newly created device. It is impossible to predict how the two devices will behave when combined. Our CE Mark testing experts have proven this on several occasions for manufacturers in various industries.

A recent example involved our engineers testing the output of two CE-marked components for a global healthcare company. The manufacturer sought to offer one component as an “add on” to the other. However, when combined, the electromagnetic output exceeded the EU requirements. The components were retested individually and each passed the required test. Ultimately, the manufacturer introducing the product to the EU market is responsible for its compliance. CMG quickly implemented a solution that enabled the final product to bear the CE Mark and be placed on the European market.

Recognizing the Legal Risks of CE + CE

The synergy of the “new product” surpasses the sum of its components, and there is no legal argument to the contrary. This principle holds true across all directives and is explicitly stated in the EMC Directive 2004/108/EC. Using this directive as an example, the permissible radio-frequency emissions from a piece of equipment are determined by the potential for interference with radio or TV reception. In the context of industrial components like PLCs, power supplies, or motor drives, the emissions limits align with those applicable to control panels, systems, or installations.

Following the flawed logic of “CE + CE = CE”, these control panels, systems, or installations may inadvertently emit signals that interfere with commercial aviation, military operations, as well as nearby radio or TV sets. Such interference not only poses a risk of non-compliance but also draws the attention of Trading Standards Officers, who have the authority to shut down installations they deem non-compliant—a power they have not hesitated to exercise in the past.


To ensure compliance for the combined device, manufacturers must follow a dedicated process. This involves a comprehensive risk assessment, testing, and documentation to prove conformity with the relevant EU directives.

At CMG, our engineers do more than simply pass or fail a product’s performance. During testing, our engineers proactively identify issues, share initial results, and recommend modifications or solutions to help clients achieve their CE Mark goals. This feedback and guidance during the test process is the key to completing the CE Mark test program in a timely, cost-effective, and successful manner.