UL is short for Underwriter Laboratories Inc. UL safety testing institute is the most authoritative in the United States and a large non-governmental organization engaged in safety testing and identification in the world. It is an independent, non-profit professional organization that does experiments for public safety. It uses scientific testing methods to study and determine whether various materials, devices, products, equipment and buildings are harmful to life and property and the degree of harm; Determine, prepare and issue corresponding standards and materials that help to reduce and prevent loss of life and property, and carry out fact investigation business at the same time.
UL is short for Underwriter Laboratories Inc. UL safety testing institute is the most authoritative in the United States and a large non-governmental organization engaged in safety testing and identification in the world. It is an independent, non-profit professional organization that does experiments for public safety. It uses scientific testing methods to study and determine whether various materials, devices, products, equipment and buildings are harmful to life and property and the degree of harm; Determine, prepare and issue corresponding standards and materials that help to reduce and prevent loss of life and property, and carry out fact investigation business at the same time. In short, it is mainly engaged in product safety certification and operating safety certification business. Its ultimate purpose is to obtain goods with considerable safety level for the market and contribute to the guarantee of personal health and property safety. As far as product safety certification is an effective means to eliminate technical barriers to international trade, UL also plays a positive role in promoting the development of international trade.
UL was founded in 1894. At the initial stage, UL mainly relied on the funds provided by the fire insurance department to maintain its operation. It was not until 1916 that UL was completely independent. After nearly a hundred years of development, UL has become a world-renowned certification body. It has a set of strict organization and management system, standard development and product certification procedures. UL is managed by a Council composed of safety experts, government officials, consumers, education, public utilities, insurance and standards departments, and its daily work is handled by the president and vice president. At present, UL has five laboratories in the United States, headquartered in Northbrook town north of Chicago, and has set up corresponding laboratories in Taiwan and Hong Kong.
Significance of UL certification mark to enterprises:
1. The whole American market pays great attention to product safety; When consumers and buyers buy products, they will choose products with UL certification marks.
2. UL has a history of more than 100 years. The image of safety is deeply rooted in consumers and the government. If you don't sell products directly to consumers, middlemen will also require products to have UL certification marks to make products sell well.
3. American consumers and buyers have more confidence in the products of enterprises.
4. More than 40000 federal, state, county and municipal governments across the United States recognize the UL certification mark.
The applicant submits relevant company and product information
Written application: you should ask UL company to test your products in writing.
Company information: provide detailed and accurate name, address, contact person, postal code, telephone and fax of the following units in Chinese and English.
(a). Applicant company: the company that applies for product testing and is responsible for all engineering service costs
(b). Listed companies: companies listed in various product catalogs published by UL
(c). Production factory: the manufacturer and producer of products.
Product information: product information shall be provided in English.
(a). Product Name: provide the full name of the product.
(b). Product model: list in detail the model, variety or classification number of all products to be tested.
(c). Intended use of the product: for example, home, office, factory, coal mine, ship, etc.
(d). Parts list: list the parts and components of the product, model (classification number), rated value and the name of the manufacturer. For insulation material, please provide the name of raw material, e.g. Ge polycarbonate, Lexan type 104. When the parts have been listed or approved by UL, please prove the specific model of the parts and indicate its UL file number (E) Electrical performance: for electronic and electrical products. Provide electrical schematic diagram (circuit diagram) and electrical performance table.
(f). Structure diagram: for most products, the structure diagram or explosion diagram, ingredient list, etc. of the product shall be provided.
(g). Photos, instructions, safety items or installation instructions of the product.
Make decisions based on the product information provided
When the product data are complete, UL engineers make the following decisions based on the data: UL standard on which the experiment is based, engineering cost of the test, test time, sample quantity, etc., notify you in writing, and send the formal application form and tracking service agreement to your company. The expense limit indicated in the application form is the maximum engineering cost estimated by UL according to the test items. Without the written authorization of your company, the expense limit cannot be exceeded. Remittance from the applicant company, return the application form and samples
The applicant shall sign the application form and tracking service agreement, and return the form to UL company. At the same time, the samples shall be sent by bank remittance, post office or express mail. Please give appropriate description (such as name and model) to the samples sent for inspection. Please send the application form and samples separately. For each applied project, UL will specify a unique project number (Project No.) and indicate the project number and the name of the applicant company when remitting, sending samples and application forms, so as to facilitate UL's check.
After receiving the application form, remittance and experimental samples signed by your company, UL will inform you of the completion time of the experimental plan. Product testing is generally conducted in UL laboratories in the United States, and UL can also accept audited third-party test data. The experimental samples will be returned or destroyed according to your requirements.
If the product test results meet the requirements of UL standards, UL will issue a test qualification report and follow up service procedure. The test report will detail the test conditions, the indicators reached by the sample, the product structure and the safety signs suitable for the product. The detailed tracking service rules include the description of the product and the guidance instructions for UL regional inspectors. A copy of the test report shall be sent to the application company, and a copy of the tracking service rules shall be sent to each production plant.
The applicant is authorized to use the UL Mark
UL regional inspectors in China contact the production factory for initial production inspection (IPI). The inspectors check the storage of your products and their parts in the production line and warehouse to confirm whether the product structure and parts are consistent with the tracking service rules. If required in the rules, the regional inspectors will also conduct witness experiments, When the inspection results meet the requirements, the applicant is authorized to use the UL Mark.
After IPI, the inspector will irregularly go to the factory to inspect the product structure and witness experiments. The frequency of inspection depends on the product type and production volume. Most types of products are inspected at least four times a year. The inspector's inspection is to ensure that the products continue to be consistent with UL requirements. Please inform UL before you plan to change the product structure or components, For minor changes, there is no need to repeat any experiment. UL can quickly modify the tracking service rules so that the inspector can accept such changes. When UL considers that the change of the product affects its safety performance, the applicant company needs to resubmit the sample for necessary testing.
The cost of tracking service is not included in the test cost.
If the product test results cannot meet the requirements of UL standards, UL will notify the applicant to explain the existing problems. After the applicant improves the product design, the product can be re submitted for inspection. You should tell UL engineers what improvements have been made to the product for their decision 
IV. UL inspection rules, certification review and follow-up inspection rules
UL inspector's inspection basically belongs to mechanical operation. According to different products, the inspector's inspection basis includes bulletin, procedure, fuii (if any, included in the detailed rules) and UL standard (if required in fuii).
If the factory is producing UL products or has UL products in stock when the inspector visits the factory, the inspector will take samples in one of the following ways:
1. Take each part from the production line and a complete product from the warehouse.
2. Extract each part from the warehouse plus the complete product on the production line.
3. Extract complete products from the warehouse for splitting.
The specific number of samples depends on the detailed rules, fuii (follow-up inspection instructions), sap (standard attachment) or direct orders from UL laboratories. Inspectors may not inspect all products every time, but they will try to inspect all product categories or models within one year or at least two years.
Generally speaking, UL's requirements for the factory production system are not too high. It only requires the measurement of instruments and equipment once a year, the preservation of the factory's own inspection records, and certain control means for nonconforming products.
During the inspection, the on-site representative (UL inspector) will mainly focus on the product itself. They will check the product structure, components and assembly one by one according to the above inspection basis. For parts related to product safety, the general rules will specify that they are required to be UL certified products, and the manufacturer and model will be indicated; For injection molded parts such as shell and shield, the detailed rules will specify their raw materials and dimensional requirements. The site representative will check the above items and the UL Mark specified in the detailed rules.
In addition, if the detailed rules or fuii or standards require on-site testing of products, the on-site representative will require the factory inspector to conduct corresponding tests, and the on-site representative will witness. If the detailed rules also require sending samples to UL for tracking test, the factory shall cooperate with the inspector to make corresponding samples. After the inspector writes the sample label, provides the address and seals the samples, the factory will send them to the corresponding UL laboratory.
If the products produced by the factory fully meet the requirements of corresponding UL inspection standards, and there is no other violation of the tracking service agreement, the inspector will issue an inspection report; The factory representative shall sign the report after confirming that its contents are accurate; One inspection is completed. In case of any nonconformity with the inspection standard during the inspection, the inspector will issue a variation notice and take corresponding measures according to the specific situation.
Remove UL Mark
For unauthorized products using UL marks, the inspector will require the removal of UL marks; For products that do not meet UL requirements, the inspector will require the factory to remove UL marks or rework to make them meet the requirements; If the factory disagrees with the above treatment opinions, the UL Mark can be retained temporarily, but the shipment must be stopped. The inspector will notify the corresponding laboratory of the situation, and UL will make a reply to decide whether the UL Mark can be retained; If there are only some small problems that do not affect the safety of the product, the inspector will make a decision of temporary acceptance and report to the corresponding laboratory; If it is some obvious standard error, such as typing error or unit error, it will not affect the qualification of factory products, but as UL document processing, the inspector will also issue a change notice. Generally, unless it is the responsibility of UL company, the inspector will ask the factory to explain the non-conforming items to the corresponding laboratory, and UL will make the corresponding reply according to your explanation.
Of course, the judgment of the inspector is only temporary, and the final decision is of course in each UL laboratory. If the factory disagrees with the inspection method, it can be reported to the corresponding laboratory. At this time, the inspector is obliged to provide the corresponding contact person and contact method. After confirming that the contents recorded in the change notice are correct, the factory representative shall sign on the notice.
UL certified factory inspection
UL regional inspectors in China contact the production factory for initial production inspection (IPI). The inspectors check the storage of your products and their parts in the production line and warehouse to confirm whether the product structure and parts are consistent with the tracking service rules. If required in the rules, the regional inspectors will conduct witness experiments. When the inspection results meet the requirements, the applicant is authorized to use the UL Mark.
Following IPI, inspectors will irregularly go to the factory to inspect the product structure and witness experiments. The frequency of inspection depends on the product type and production volume. Most types of products are inspected at least four times a year (the cost of tracking service is not included in the test cost).
Before the first shipment of UL certified products, the local provincial China Import and Export Commodity Inspection Bureau (CCIC) authorized by UL shall send personnel to the factory for review. Follow up and check every year.
Introduction to tracking inspection
As an organic part of UL certification, in order to ensure that UL Listed and approved products continue to meet UL standards and requirements, UL has developed a "tracking inspection" system. "Tracking inspection" means that UL sends field representatives all over the world to the local factory production site to track and inspect UL's products. Its purpose is to check the factory's production process, inspection process and products against UL standards and tracking inspection rules to ensure that the manufacturer's production process, inspection process and products always meet UL requirements.
Basis of follow-up inspection
After the site representative arrives at the factory, the inspection is mainly carried out according to the "follow-up inspection rules". "Detailed rules for follow-up inspection" is prepared by UL engineering department after testing the samples submitted for inspection. This document includes a comprehensive description of the product, photos, instructions, etc. It also stipulates various tests that manufacturing factories often have to do during production, some of which require 100% of the products, such as pressure test. Some inspections can be carried out by sampling. At the same time, it also stipulates the test items that must be spot checked by the on-site representative during the on-site inspection of the factory. The site representative shall judge whether the inspection results are qualified according to the details and regulations of such tests.
Track the classification of inspection products
The review is divided into the first review and quarterly review. The cost of the first review is relatively higher. The tracking inspection of UL is divided into R and L. Class L service is mainly used for products related to life safety, such as fire extinguishers, smoke detectors, fire doors and some products with considerable output, such as power equipment, wires and circuit breakers. For products belonging to class L, the manufacturer must order directly from UL and affix the label on the product. Class R services are mainly used for electrical equipment, such as fans, televisions, hair dryers, ovens and other products usually produced by corresponding assembly lines.
matters needing attention
1. The minimum height of the registered trademark shall be 3 / 64 inch.
2. When the outer circle diameter of UL Mark is less than 3 / 8 inch, the registered trademark symbol can be ignored if it is not clearly readable under naked vision.
3. The mark can be directly and fixed on the same product by stamping, molding, ink printing, screen printing or similar methods.
4. Acquisition of marks: the manufacturer can reprint or obtain them from UL authorized dealers.