What is UL certification? Does it have an expiration date?
What is UL？
UL (Underwriters Laboratories) is the abbreviation for the U.S. Underwriters Laboratories. UL is one of the most authoritative safety testing organizations in the United States and one of the largest private institutions in the world engaged in safety testing and certification. As an independent, non-profit professional organization, UL is dedicated to using scientific testing methods to research and evaluate the potential hazards of various materials, devices, products, equipment, and buildings to life and property, and to establish relevant standards and solutions.
UL’s mission is to ensure that products on the market meet high safety standards through safety certification and the provision of safety evidence, protecting personal health and property safety while actively promoting the development of international trade. Since its establishment in 1894, UL has developed into a globally recognized certification organization, with a rigorous management system, standard development processes, and product certification procedures. Currently, UL has five laboratories in the United States, with its headquarters located in Northbrook, a suburb of Chicago. It also has corresponding laboratories in Taiwan and Hong Kong.
UL Certified product categories
UL’s product certification types include：
- Listed：Applies to complete products that are typically marked with the UL Listed mark.
- Recognized：Applies to incomplete products or products with restricted use, such as electronic wires, processed wires, etc.
- Classification：Evaluates specific hazards of a product or its compliance with specific international standards.
- Multiple Listings or Recognitions：Allows the same product to be sold under different company names.
- System Certification Services：Includes certifications such as ISO 9000 Quality Management System certification and ISO 14000 Environmental Management System certification.
UL Certification Process
- Application：Provide relevant information about the applicant (responsible for all application processes and payment of fees), the manufacturer (production factory), and the registrant (product registration entity).
- Testing and Inspection：After submitting samples, specifications, and material descriptions, testing and inspection will be conducted, and UL engineers will issue a test report.
- Factory Inspection: Includes Initial Production Inspection (IPI) and Factory Production Inspection (FPI) to ensure continuous compliance with UL standards.
- Certification Issuance: After completing the inspection, UL issues a certification report and authorization documents.
UL The Importance of Certification
As a manufacturer focused on high-efficiency air filters, we deeply understand the importance of UL certification for market trust and product safety. Through UL certification, our air filter products can effectively improve indoor air quality, making them particularly suitable for environments that require high air quality, such as hospitals, semiconductor factories, and the electronics manufacturing industry. Our products undergo scientific testing and meet strict safety and performance standards, providing customers with the highest level of trust and assurance.
UL The Validity of Certification
UL certification itself does not have a fixed validity period; its validity mainly depends on whether the company continues to comply with UL’s requirements. Specifically, this includes:
Regular Factory Inspections: The factory needs to undergo 1 to 4 inspections annually to ensure that the production process complies with UL’s requirements.
Payment of Maintenance Fees: The company must pay the file maintenance fees or inspection fees on time.
Stability of Product Specifications: If the product’s specifications, structure, or key parameters have not changed, the certification will remain valid.
Response to Standard Changes: When there is a significant change in certification standards, the company must conduct updated testing as required.
As long as the factory completes inspections on time, pays the maintenance fees, and ensures that the product meets current standards, the UL authorization page will remain valid, and the company can continue using the UL mark for product sales.
However, Hencolin’s ISO 9001 management system certification, conducted every four years, continuously complies with the verified scope. Its verification scope covers the manufacturing and sales services of air filters used in industrial, central air conditioning, and exhaust air intake boxes.
About UL Solutions
As a global expert in the field of safety science, UL Solutions helps customers address product safety, information security, and sustainability challenges in over 100 countries. UL Solutions provides testing, inspection, and certification services, driving product and business growth through science and innovation.
As an air filter manufacturer, we work closely with UL Solutions to ensure that every product excels in safety, performance, and environmental standards. Our goal is to help customers improve indoor air quality through high-performance filter products and work together towards a healthier and more sustainable future.
