UL 1598C 3rd Edition Raises Smart Lighting Tests

On May 30, 2026, UL published the third edition of UL 1598c, adding new surge immunity and EMC requirements for Smart Lighting products. The update deserves attention from LED luminaire exporters, smart lighting manufacturers, wireless control solution providers, certification teams, and supply chain service providers because the new requirements will become mandatory for UL certification from December 1, 2026.

Event Overview

UL released the third edition of UL 1598c on May 30, 2026. According to the available information, the updated standard adds an IEC 61000-4-5 Level 4 surge immunity test requirement, including 4 kV line-to-ground testing, for Smart Lighting products.

The update also introduces CISPR 15:2018 Class B radiated disturbance limit requirements. The scope covers LED luminaires with wireless communication functions, including Zigbee, Matter, and Bluetooth LE, as well as LED luminaires with dimming control functions.

The new requirements will become mandatory items for UL certification from December 1, 2026. Based on the disclosed information, the update is directly related to Smart Lighting products intended for the U.S. market that require UL certification.

Which Industry Segments Are Affected

Exporters of Smart Lighting Products

From an industry perspective, exporters shipping Smart Lighting products to the United States are among the most directly affected parties. The reason is that the new requirements are tied to UL certification, and the mandatory date has been set for December 1, 2026.

The impact may mainly appear in certification planning, shipment scheduling, and product documentation review. Exporters handling LED luminaires with Zigbee, Matter, Bluetooth LE, or dimming control functions should pay particular attention to whether existing certified models will need additional testing under the updated UL 1598c requirements.

LED Luminaire Manufacturers

Analysis shows that manufacturers of LED luminaires with wireless communication or dimming control functions may need to review product design and testing arrangements more carefully. The update adds both surge immunity and radiated disturbance requirements, which may affect how manufacturers prepare products for UL certification.

The main impact is likely to appear in pre-compliance testing, engineering verification, and certification timelines. For manufacturers with products already under development, the December 1, 2026 mandatory date creates a clear compliance checkpoint that should be considered before finalizing production and certification schedules.

Wireless and Dimming Control Solution Providers

From an industry perspective, solution providers involved in Zigbee, Matter, Bluetooth LE, or dimming control functions may also be affected because the updated standard specifically covers LED luminaires with these capabilities.

The influence is not limited to the complete luminaire manufacturer. Control modules, wireless communication functions, and dimming-related designs may become more closely reviewed during product-level certification. What deserves closer attention now is whether the complete luminaire can meet the newly added surge and EMC requirements when these functions are integrated.

Certification, Testing, and Compliance Service Providers

Observably, testing and compliance service providers will need to align their project planning with the new UL 1598c third edition requirements. Since the update adds IEC 61000-4-5 Level 4 and CISPR 15:2018 Class B radiated disturbance requirements, test planning for applicable Smart Lighting products may need to be adjusted accordingly.

The impact may appear in test item confirmation, certification communication, and customer guidance before the mandatory date. Service providers should clearly distinguish between products that fall within the stated scope and products that do not, based on the presence of wireless communication or dimming control functions.

Channel and Distribution Businesses

Analysis shows that channel and distribution businesses serving the U.S. lighting market should pay attention to certification status and product applicability. If Smart Lighting products entering the channel after the mandatory date require UL certification under the updated rules, incomplete compliance confirmation may affect procurement and sales arrangements.

The main issue for distributors is not technical testing itself, but whether suppliers can provide updated certification information in time. For products with wireless communication or dimming control functions, channel partners may need clearer confirmation before placing orders or planning inventory.

What Companies and Practitioners Should Watch and How to Respond

Confirm Whether Products Fall Within the Updated Scope

Companies should first identify whether their LED luminaires include Zigbee, Matter, Bluetooth LE, or dimming control functions. The disclosed scope of the updated UL 1598c requirements specifically points to LED luminaires with wireless communication or dimming control capabilities.

From an industry perspective, this scope confirmation should be handled before certification scheduling. Products outside the stated scope should not be automatically treated as affected, while products with the listed functions should be reviewed against the new test requirements.

Review Certification Timelines Before December 1, 2026

The mandatory date is a key operational point. Companies planning UL certification for applicable Smart Lighting products should check whether certification projects may extend beyond December 1, 2026.

Analysis shows that the practical response is to align product development, sample preparation, testing, and certification communication around this date. For projects already in progress, companies should confirm with relevant certification contacts how the transition to the third edition requirements will be handled.

Prepare for Surge Immunity and EMC Test Requirements

The update adds IEC 61000-4-5 Level 4 surge immunity testing, including 4 kV line-to-ground testing, and CISPR 15:2018 Class B radiated disturbance limits. Companies should ensure that internal engineering teams and external testing partners are working from the same requirement set.

What deserves closer attention now is not only whether a product can pass a single test, but whether the product design, documentation, and certification plan are consistent with the updated UL 1598c requirements. This is especially relevant for Smart Lighting products that combine LED lighting, wireless communication, and dimming control functions.

Strengthen Supplier and Customer Communication

Exporters, manufacturers, and distributors should communicate the new requirements across the supply chain. For applicable Smart Lighting products, suppliers should be asked to clarify whether models are designed and tested with the new UL 1598c third edition requirements in mind.

More appropriately understood as a compliance transition issue, the update may require clearer documentation exchange between manufacturers, exporters, channel partners, and testing service providers. Early communication can reduce uncertainty around procurement, delivery planning, and certification readiness.

Editor’s View / Industry Observation

Analysis shows that the UL 1598c third edition update is more than a routine standard revision for companies involved in Smart Lighting exports to the United States. Because it adds defined surge immunity and EMC requirements and sets a mandatory certification date, it creates a practical compliance timeline for affected products.

More appropriately understood as both a regulatory signal and an upcoming certification requirement, the update indicates that Smart Lighting products with wireless communication or dimming control functions are facing more specific electrical immunity and radiated disturbance expectations under UL certification.

Observably, the industry needs to continue monitoring how certification projects apply the new requirements in practice. The confirmed information already establishes the standard update, scope, test items, and mandatory date, while practical implementation details may still require ongoing attention during actual certification work.

Conclusion

The release of UL 1598c third edition is significant for Smart Lighting companies targeting the U.S. market. It directly affects LED luminaires with Zigbee, Matter, Bluetooth LE, or dimming control functions and adds clear surge immunity and EMC testing requirements to UL certification from December 1, 2026.

From an industry perspective, the update should be understood as a concrete compliance milestone rather than a general market trend. The most rational response is to confirm product scope, review certification schedules, prepare for the new test items, and maintain close communication across engineering, certification, export, and channel teams.

Information Source Statement

Main source: UL 1598c third edition release information dated May 30, 2026.

Information currently available: the publication date, added IEC 61000-4-5 Level 4 4 kV line-to-ground surge immunity requirement, added CISPR 15:2018 Class B radiated disturbance limits, applicable product scope, and December 1, 2026 mandatory UL certification date.

Items requiring continued observation: practical certification transition arrangements, product-level applicability confirmation, and implementation details during UL certification projects for Smart Lighting products.