Christmas Lights China
Guides

Safety and quality

UL, ETL and CSA listings and quality checks for imported lights

A safety mark on a box of lights is a claim that a specific product, made at a specific factory, was tested to a standard and is under ongoing follow-up inspection. When you import, checking that claim becomes your job.

Updated September 27, 2026. Prices checked September 27, 2026.

What the marks are

UL, ETL and CSA are certification marks issued by testing organizations recognized by OSHA as Nationally Recognized Testing Laboratories (NRTLs). UL Solutions issues the UL mark, Intertek issues the ETL mark, and CSA Group issues the CSA mark. Each can certify products to the same US safety standards, so an ETL-listed light string and a UL-listed light string can be tested to the same requirements. The mark tells you who certified it; the listing tells you what was certified.

A listing belongs to a product and a factory

Listings are tied to the certified product design and to the factory locations the certifier inspects. That has practical consequences when sourcing from overseas:

  • A factory showing you a listing certificate for one product does not mean every product it makes is listed.
  • A product made by a subcontractor or at a different plant may not be covered by the listing shown to you.
  • Changing the design after listing, such as a thinner wire or a different socket, can take the product outside what was certified.
  • Marks must be applied under the certifier's program; a printed logo on a box is not the listing itself.

How to verify before you pay

  1. Ask the factory for the certifier's file or control number for the exact model you are ordering.
  2. Look that number up in the certifier's own public online directory, not a PDF sent by the seller.
  3. Check that the company name, factory location and model numbers in the directory match your order.
  4. Write the listed model and mark requirements into your purchase order and your inspection checklist.
  5. Have the pre-shipment inspector confirm the marks and labels on finished goods.

If you resell or install for customers

Commercial customers, property managers and insurers may ask for listed products. Keep the listing details for every imported batch on file so you can answer that question later.

Physical checks that matter for holiday lighting

Wire gauge and jacket: SPT-1 and SPT-2

Socket wire and zip cord are usually described by conductor gauge and jacket type. SPT-1 and SPT-2 are both parallel thermoplastic cord types; SPT-2 has a thicker insulation jacket than SPT-1 for the same conductor size, which makes it tougher and stiffer. Confirm the gauge and jacket printed on the wire match your spec, and that plugs and connectors are rated for that jacket. For reference, the 250 ft SPT-1 lamp cord listed by Christmas Light Supplier ($78.00) is described as 18 gauge, 2 conductor (18/2), rated 8 amps / 960 watts.

Bulb bases

C9 bulbs use the E17 intermediate screw base; C7 bulbs use the smaller E12 candelabra base. Check a sample of bulbs in your existing sockets: threads that are slightly off will seat loosely, flicker in wind and let water in.

LED color temperature and binning

White LEDs are sorted into bins by color. Two batches both labeled "warm white" can look visibly different on the same roofline if they came from different bins or LED suppliers. Specify the color temperature in Kelvin, keep an approved sample, and compare production against it under the same conditions.

Build quality

  • Socket gaskets or seals present and seated.
  • Lens material and wall thickness consistent with the sample.
  • Plugs molded or clamped firmly, with strain relief where the cord enters.
  • Spacing on socket wire matching the order (12, 15 or 24 inch are common for C9).

US consumer product rules

The US Consumer Product Safety Commission has rules covering seasonal and decorative lighting products, including treating certain characteristics, such as minimum wire size and strain relief, as substantial product hazards when missing. An importer is responsible for the products it brings in. If you import lighting to resell, get advice on your obligations before the goods ship.

Where buying from US stock changes the picture

Buying from a US distributor does not remove the need to check what you are buying, but it moves the timing: you can look at the product listing and the physical item before a large commitment, return questions go to a US business, and replacements arrive in days. Check the listing and packaging details for any specific product you buy, whether imported yourself or from a US supplier.

Frequently asked questions

Is ETL listing as good as UL listing for Christmas lights?

Both UL Solutions and Intertek (ETL) are OSHA-recognized NRTLs and can certify products to the same US safety standards. What matters is that the specific product is listed to the applicable standard and the listing checks out in the certifier's directory.

How do I check if a Chinese factory's UL listing is real?

Ask for the file or control number for the exact model, then search it in the certifier's public online directory. Confirm the company name, factory location and model numbers match your order.

What is the difference between SPT-1 and SPT-2 wire?

Both are parallel thermoplastic cords. SPT-2 has thicker insulation than SPT-1 for the same conductor gauge, making it more durable and stiffer. Plugs and connectors must match the jacket type.

What bulb base do C9 and C7 Christmas lights use?

C9 bulbs use the E17 intermediate base and C7 bulbs use the E12 candelabra base.