Wire Harness Standards Decoded: UL, RoHS, REACH — What Every Engineer Must Know
Why Compliance Standards Matter for Wire Harness Selection
When an electronics engineer selects a wire harness or connector assembly, compliance with international standards is not an optional consideration — it is a market access requirement. Products sold in the European Union must comply with RoHS and REACH. Products sold in North America typically require UL-listed wire. Products sold in multiple markets must satisfy multiple overlapping compliance frameworks.
Non-compliance is not a minor administrative issue. It can result in product recalls, customs seizure, market withdrawal, and significant financial and reputational damage. For OEM customers, a non-compliant component in the supply chain can trigger compliance failures across an entire product line.
At Keszoox, compliance is built into our product selection and manufacturing process — not added as an afterthought. This article explains the key compliance standards relevant to wire harness and connector assemblies, what they require, and how Keszoox products support your compliance obligations.
UL Listings: Wire Safety Standards for North American Markets
What UL Is
UL (Underwriters Laboratories) is an independent safety certification organization that develops and applies safety standards for electrical and electronic components. UL listings for wire and cable confirm that the wire has been tested and certified to meet specific safety requirements for insulation material, voltage rating, temperature rating, and flame resistance.
UL listings are not legally mandatory in all applications, but they are required or strongly preferred in many North American markets, particularly for products sold to commercial and industrial customers, products subject to building codes or electrical codes, and products requiring insurance coverage.
UL1007 — Hook-Up Wire, 300V, 80°C
UL1007 is a PVC-insulated hook-up wire rated at 300V and 80°C maximum conductor temperature. It is one of the most widely used wire types for internal wiring of electronic equipment in North American markets.
Key UL1007 specifications:
Voltage rating: 300V
Temperature rating: 80°C (conductor), −40°C minimum
Insulation material: PVC (polyvinyl chloride)
Flame resistance: UL VW-1 vertical flame test
Conductor: Stranded tinned copper
UL1007 is appropriate for general-purpose internal wiring in electronic equipment operating in standard temperature environments. It is not appropriate for high-temperature applications or applications requiring high flexibility.
UL1061 — Hook-Up Wire, 300V, 80°C (Lighter Construction)
UL1061 is similar to UL1007 but with a thinner insulation wall, resulting in a smaller overall diameter for a given conductor gauge. It is used where space is constrained or where a lighter, more flexible wire is preferred for the application.
Key UL1061 specifications:
Voltage rating: 300V
Temperature rating: 80°C (conductor)
Insulation material: PVC
Flame resistance: UL VW-1 vertical flame test
Conductor: Stranded tinned copper
UL1061 is Keszoox's standard wire type for general-purpose connector kits and assemblies. Its thinner insulation wall makes it well-suited for the small-pitch connector assemblies (JST PH, XH, ZH) that are common in compact electronics.
🛒 JST EH 2.5mm Kit with UL1061 Wire · Molex KK 254 Kit with UL Wire
Silicone Wire — High-Temperature, High-Flex Applications
Silicone-insulated wire is not covered by UL1007 or UL1061 — it falls under different UL standards (such as UL3132 for silicone rubber-insulated wire). Silicone wire is used where UL1007/1061 PVC wire is inadequate: high-temperature environments (up to +200°C), high-flex applications, or applications requiring low-temperature flexibility (down to −60°C).
Keszoox uses silicone wire in custom harness manufacturing for applications including battery management systems, motor wiring, robotics, and other high-flex or high-temperature applications.
RoHS: Restriction of Hazardous Substances
What RoHS Is
The EU RoHS Directive (2011/65/EU, amended by 2015/863/EU) restricts the use of specific hazardous substances in electrical and electronic equipment sold in the European Union. RoHS compliance is a legal requirement for products placed on the EU market — non-compliant products cannot legally be sold in the EU.
Restricted Substances Under RoHS
RoHS restricts ten substances in electrical and electronic equipment:
Lead (Pb): Maximum 0.1% by weight in homogeneous materials. This is the most significant restriction for connector and wire harness assemblies — it prohibits lead-based solder and lead-containing plating on connector terminals.
Mercury (Hg): Maximum 0.1% by weight.
Cadmium (Cd): Maximum 0.01% by weight.
Hexavalent chromium (Cr VI): Maximum 0.1% by weight. Relevant for metal connector housings with chromate surface treatments.
Polybrominated biphenyls (PBB): Maximum 0.1% by weight. Relevant for plastic connector housings and wire insulation materials.
Polybrominated diphenyl ethers (PBDE): Maximum 0.1% by weight. Relevant for plastic materials.
DEHP, BBP, DBP, DIBP (phthalates): Maximum 0.1% by weight each. Added by 2015/863/EU amendment. Relevant for PVC wire insulation, which historically used phthalate plasticizers.
RoHS Compliance for Connector and Wire Harness Assemblies
For wire harness assemblies, RoHS compliance requires:
Connector terminals: Lead-free plating (typically tin or gold plating over copper or brass base metal). Keszoox connector terminals use lead-free plating compliant with RoHS requirements.
Connector housings: Plastic materials free from PBB, PBDE, and phthalate plasticizers. Keszoox connector housings use RoHS-compliant plastic materials.
Wire insulation: PVC insulation must use RoHS-compliant (phthalate-free) plasticizers. Keszoox wire meets RoHS phthalate requirements.
All Keszoox products are manufactured in compliance with EU RoHS Directive 2011/65/EU as amended by 2015/863/EU. RoHS compliance declarations are available on request.
🛒 JST SM 2.5mm RoHS-Compliant Kit · Molex KK 254 RoHS-Compliant Kit
REACH: Registration, Evaluation, Authorisation and Restriction of Chemicals
What REACH Is
REACH (Regulation EC No 1907/2006) is the EU's comprehensive chemicals regulation. It requires manufacturers and importers to identify and manage risks associated with chemical substances used in their products. For electronics components, the most relevant aspect of REACH is the SVHC (Substances of Very High Concern) candidate list.
SVHC Obligations for Component Suppliers
Under REACH Article 33, suppliers of articles (including electronic components) must inform customers if the article contains more than 0.1% by weight of any substance on the SVHC candidate list. The SVHC list is updated regularly by the European Chemicals Agency (ECHA) and currently contains over 240 substances.
For wire harness and connector assemblies, SVHC substances of concern include certain phthalates (already restricted under RoHS), certain flame retardants used in plastic housings, and certain heavy metal compounds used in surface treatments.
Keszoox REACH Compliance
Keszoox monitors the SVHC candidate list and works with our material suppliers to ensure that our products do not contain SVHC substances above the 0.1% threshold. REACH compliance declarations and SVHC substance information are available on request for OEM and industrial customers with supply chain compliance requirements.
CE Marking and the EU Declaration of Conformity
CE marking indicates that a product complies with applicable EU directives and regulations, including RoHS and REACH where relevant. For electronic components and sub-assemblies (including wire harnesses and connector kits), CE marking requirements depend on the product category and its intended application.
Wire harness assemblies supplied as components for incorporation into end products are typically covered by the end product manufacturer's CE marking process rather than requiring independent CE marking as components. However, OEM customers incorporating Keszoox harnesses into CE-marked products may require compliance documentation from Keszoox to support their Declaration of Conformity.
Keszoox provides RoHS compliance declarations and REACH SVHC information to support our customers' CE marking processes.
Practical Compliance Checklist for Engineers
When specifying wire harness assemblies for products targeting global markets, use this checklist to ensure compliance requirements are addressed:
☐ EU market: Confirm RoHS compliance for all connector terminals, housings, and wire insulation. Confirm REACH SVHC compliance. Obtain compliance declarations from supplier.
☐ North American market: Specify UL-listed wire (UL1007 or UL1061 for standard applications). Confirm wire UL listing covers the voltage and temperature requirements of the application.
☐ High-temperature application: Verify wire temperature rating covers maximum operating temperature with appropriate margin. Consider silicone wire for applications above 80°C.
☐ High-flex application: Specify silicone wire or other high-flex wire type. Verify strand count and conductor construction for flex life requirements.
☐ OEM supply chain documentation: Request RoHS compliance declarations, REACH SVHC declarations, and UL listing documentation from wire harness supplier.
Summary
UL, RoHS, and REACH compliance is not optional for wire harness assemblies in global electronics markets — it is a market access requirement. UL listings confirm wire safety for North American markets. RoHS restricts hazardous substances in EU-market products. REACH requires SVHC substance disclosure. Keszoox products are manufactured in compliance with these standards, and compliance documentation is available on request to support our customers' market access requirements.
🛒 Shop RoHS & UL-compliant connector kits: JST EH 2.5mm Kit · JST SM 2.5mm Kit · Molex KK 254 Kit · Molex DIP Header Kit