When selecting materials for contact with drinking water, ensuring safety and regulatory compliance is crucial. In the UK, WRAS approved status is the established standard certifying that a product or material meets strict requirements for use in potable water systems. For engineers, buyers and industrial decision-makers specifying silicone rubber components, understanding WRAS approval is essential. This article explains what WRAS approval means, its importance and how to specify WRAS-compliant silicone materials correctly.
What Does ‘WRAS Approved’ Mean?
To begin, it is important to clarify what WRAS approval entails and the standards it upholds.
WRAS approved meaning
WRAS stands for the Water Regulations Advisory Scheme, which recognises products and materials that have been independently tested to confirm they are suitable for contact with drinking water.
When a material or product is WRAS approved, it has undergone rigorous testing to confirm it will not contaminate or adversely affect water quality.
What WRAS approval signifies
Compliance with UK water regulations
WRAS approval confirms that materials comply with the Water Supply (Water Fittings) Regulations 1999 and related UK Water Byelaws. These legal frameworks ensure potable water is protected from contamination and wastage.
Protection against water contamination
Materials must prove they do not leach harmful substances or cause taste or odour issues in water. WRAS-approved materials are assessed for chemical inertness to prevent contamination.
Quality and safety assurance
WRAS approval ensures adherence to recognised standards, such as BS 6920, which defines test methods for non-metallic materials in contact with drinking water. This provides confidence that approved materials do not adversely affect drinking water quality.
Material data sheets supplied by manufacturers allow specifiers to evaluate mechanical properties and long-term performance separately, ensuring the selected material is suitable for both compliance and application requirements.
Why WRAS Approval Is Important
WRAS approval is important for a number of reasons:
Legal and regulatory considerations
In many UK construction and water supply projects, WRAS-approved products are widely used to demonstrate compliance with the Water Supply (Water Fittings) Regulations. Employing non-approved materials risks regulatory breaches, project delays or increased costs.
Protecting drinking-water quality
Only WRAS-approved materials have been assessed to ensure they do not compromise water quality, safeguarding public health and reinforcing consumer confidence. Using a non-WRAS-approved material risks affecting drinking water quality and the penalties associated with that.
Reducing compliance and project risk
Specifying WRAS-compliant silicone materials from the start reduces the chance of non-compliance, helping avoid costly rework and supporting efficient project delivery and approvals. We regularly support customers by advising on suitable silicone materials that meet WRAS standards to mitigate such risks.
WRAS Approval and Silicone Rubber Materials
With the importance of WRAS approval established, it is essential to understand how this applies specifically to silicone rubber materials.
WRAS approval vs finished-part compliance
WRAS approval commonly applies to raw silicone rubber materials. Final parts must be manufactured under controlled conditions to maintain compliance, as processes such as moulding and curing can influence material properties.
Importance of correct processing and post-curing
Strict adherence to recommended processing and post-curing guidelines is critical to preserve WRAS drinking water compliance. Incorrect handling may alter material characteristics or introduce contaminants.
Food-grade vs drinking-water compliance
Food-grade silicone is designed for safe food contact but does not automatically meet the more stringent potable water requirements. WRAS-approved silicone specifically satisfies these higher drinking water safety standards.
WRAS Approved Grades and Material Options
To specify WRAS-compliant materials effectively, it helps to understand the available silicone grades and their characteristics.
Overview of WRAS-compliant silicone grades
WRAS-approved silicone rubber grades are formulated and tested following BS 6920 criteria. These grades exhibit low chemical extractables and are confirmed suitable for contact with drinking water when processed in accordance with manufacturer recommendations.
Shore hardness options and application considerations
WRAS-approved silicones are available in a range of Shore A hardness levels, typically 20–80 Shore A, allowing selection to be based on sealing performance, flexibility and application requirements.
Temperature limits and scope of approval
Each WRAS-approved silicone grade specifies allowable operating temperatures and approved uses. It is important to verify these limits align with your application to ensure ongoing compliance, suitability and reliable performance.
How to Specify WRAS-Compliant Materials Correctly
When it comes to WRAS-compliant materials, there are some best practices to follow for clear and effective specification. These include:
Referencing material grades on technical drawings
Technical drawings and specifications should explicitly state the precise WRAS-approved silicone grade, supplier details and the WRAS approval number. This avoids ambiguity and supports consistent compliance.
Avoiding future compliance issues through clear specification
A clear, detailed specification minimises the risk of material substitutions with non-WRAS-compliant products during procurement or manufacturing. We routinely help customers draft these specifications to ensure material traceability and regulatory adherence throughout the supply chain.
Documentation, Traceability and Declarations
Accurate documentation and traceability are vital parts of maintaining WRAS compliance.
What documentation may be required
Essential documents include WRAS approval certificates, test reports (in line with BS 6920), and declarations of conformity. These underpin compliance claims and support audit trails.
Role of manufacturer quality support
Collaborating with experienced manufacturers offers access to robust quality assurance, technical guidance, and comprehensive documentation. This support simplifies compliance management and helps manage regulatory risk effectively.
How to Check WRAS Compliance
To conclude the technical overview, understanding how to verify WRAS compliance is key.
Using WRAS statements and approval references
Materials with WRAS approval carry unique approval numbers, which you can ask your supplier for and are often found on material data sheets or official statements. Verification through the WRAS online directory confirms the approval’s validity and authenticity.
Understanding approval numbers and scope
Each WRAS approval covers a specific formulation and defined application scope. Carefully reviewing these details ensures the selected material matches your intended use.
What this means in practice for specifiers
Applying WRAS compliance principles in your projects involves clear, practical steps:
- Specify the exact WRAS-approved silicone grade and supplier information on technical drawings and documentation.
- Choose materials with verified compliance to BS 6920 and ensure their approved temperature and application ranges match your requirements.
- Follow recommended processing and post-curing protocols to maintain material integrity and WRAS status throughout manufacturing.
- Maintain comprehensive documentation including WRAS certificates and test reports for traceability and audit purposes.
- Work closely with experienced manufacturers who provide technical support and quality assurance to navigate compliance complexities confidently.
Frequently Asked Questions (FAQ)
What does WRAS approved mean?
WRAS approved indicates a material or product has met UK regulatory requirements for safe use in contact with potable water.
Is food-grade silicone the same as WRAS approved silicone?
No. Food-grade silicone is safe for food contact, but WRAS approval certifies compliance with stricter drinking water safety standards.
Does WRAS approval apply to finished parts or just raw material?
WRAS approval usually covers raw materials. Finished parts must be manufactured properly to maintain WRAS compliance.
What standards are used to test drinking-water materials?
The key standard is BS 6920, which evaluates the effect of materials on drinking water quality.
How do I specify WRAS compliant materials on a technical drawing?
Include the exact material grade name associated with the WRAS-approved silicone grade to ensure compliance in procurement and manufacturing. You can also add extra information such as supplier information and the WRAS approval reference number.
Conclusion
WRAS approval is fundamental to ensuring material safety, legal compliance, and drinking water quality protection across UK potable water systems. For silicone rubber components, understanding the difference between raw material and finished part compliance, following clear specifications and maintaining thorough documentation reduces project risk and supports public health objectives.
We regularly support customers by providing WRAS-approved silicone rubber materials with robust technical compliance and quality assurance. Partnering with knowledgeable UK silicone extrusion manufacturers ensures you meet regulatory and performance standards confidently.
For tailored advice on WRAS-compliant silicone materials suitable for your drinking water applications, consult an experienced UK silicone extrusion manufacturer specialising in regulatory compliance and technical support. Contact us today for expert advice and sample requests. We support your project from design through certification to supply.