The UL® mark on the side of a cabinet, enclosure, or PDU isn’t just a formality. It signals whether that product has passed rigorous safety testing.
But not all UL marks mean the same thing. Some products are UL Certified, while others are only tested to UL standards—and that difference can be the line between smooth compliance and costly setbacks.
Adding to the complexity, UL continues to update the standard, turning what may appear to be a minor technical detail into a significant factor in how compliance is measured—and ultimately, how risk is managed.
This guide unpacks what those standards really mean in practice—and why understanding them is critical if you’re making decisions about IT deployments today.
Why UL Compliance Matters for IT Equipment
OSHA requires all electrical products used in the workplace to be approved by a Nationally Recognized Testing Laboratory (NRTL). In practice, that means most IT leaders look for the UL® mark—the most widely recognized NRTL worldwide.
UL certification is also an entry point to the international CB (certification body) scheme, which global operators increasingly require. In July 2025, OSHA expanded UL’s scope as a recognized NRTL, adding more test sites (including new global locations like Vietnam) and covering additional standards. This expansion makes it easier for manufacturers to gain approvals worldwide, but it also underscores the importance of ensuring equipment is certified to the latest UL requirements, not legacy versions.
But here’s where it gets tricky: a product can be UL Certified or merely tested to UL standards. Both may carry a UL mark, but only one carries the full weight of UL’s certification, ongoing audits, and system-level testing.
When evaluating IT products, there are two primary criteria every organization should check:
- Is the product UL Certified or just “Tested to UL standards”?
- Which standard does it comply with—UL 60950 or the current benchmark, UL 62368?
UL Certified vs. Tested to UL Standards
At first glance, a UL mark looks like a simple stamp of approval. But what’s behind it matters.
UL Certified means the product has been tested directly by UL—not a third party. And it’s not just a one-time check. UL conducts comprehensive testing to verify that the product meets the standard in its entirety, then continues to audit the factory on a regular basis to ensure compliance is maintained. Certification applies to the complete product, not just its components, which provides a much stronger guarantee of safety and reliability.
UL Certified Products:
- Tested directly by UL, not a third party
- Undergo comprehensive testing against the full standard
- Factories are audited regularly to maintain compliance
- Certification applies to the entire system, not just components
By contrast, products labeled “Tested to UL standards” have been evaluated by another NRTL using UL’s published requirements. While this might sound equivalent, it often isn’t. Interpretations vary across labs, testing is sometimes limited to “UL recognized” components, and the safety issues that arise when components interact can go untested.
Products “Tested to UL Standards”:
- Evaluated by another NRTL using UL’s published standards
- Interpretations vary across labs
- Often only check whether major components are “UL recognized”
- May overlook risks that arise when parts interact
As a result, a product may technically pass as “tested to UL standards” but still fall short of OSHA requirements, leave gaps in safety, or create vulnerabilities that surface later during an audit or insurance claim.
How to Verify if Equipment is UL Certified:
Look for the official UL certification mark and request documentation from your vendor. Don’t rely on vague labels that only say, “tested to UL standards.” True UL certification includes system-level testing and ongoing factory audits that provide far greater assurance.
UL 62368 vs. UL 60950: The Current Benchmark
For years, UL 60950 defined safety requirements for IT equipment up to 600V. It was prescriptive: the standard dictated what components to use and under what conditions.
But IT environments have changed. Compute densities have spiked. Audiovisual equipment and IT hardware have converged. Global deployments are the norm. Prescriptive checklists no longer capture the risks.
That’s why UL 62368 replaced 60950 as the benchmark for IT and audiovisual equipment. Introduced in 2012 and enforced globally by 2020, it shifted the industry toward hazard-based safety engineering (HBSE)—a system-level approach that:
- Identifies energy sources in the system
- Classifies them by hazard potential
- Designs safeguards against those hazards
- Tests whether the safeguards work
Compared to UL 60950, UL 62368 broadens protection to cover “ordinary users,” not just trained personnel, and expands what qualifies as a fault condition. It’s stricter, more realistic, and globally aligned.
And the standard hasn’t stopped evolving. In July 2025, the 4th Edition of UL/CSA 62368-1 was published, tightening requirements further. One of the biggest changes: legacy components certified under older standards are no longer automatically accepted. If a component plays a role in safety, it must meet the 4th Edition requirements.
That means it’s no longer enough to simply ask whether equipment is UL 62368 compliant. You need to confirm it’s certified to the latest edition—otherwise you risk deploying infrastructure that may appear compliant but fails under today’s stricter expectations.
Examples of Test Differences Between UL 60950 and UL 62368
Description | IEC 60950-1 | IEC 62368-1 |
|---|---|---|
Capacitor Discharge | Test done at 240V~ and between line and neutral. Test to be done under the normal condition. Discharge voltage to be measured at one second after disconnection for pluggable type A equipment, and 10 seconds after disconnection for pluggable type B equipment. The limit is 37% of the peak voltage at the disconnection point. | Test done at 240V~ and between line and neutral as well as line and ground and finally between neutral and ground. Test to be done under both normal- as well as under single fault condition. Discharge voltage to be measured at two seconds after disconnecting. For normal conditions, two limits need to be satisfied. The limit for the ordinary person is ES1 and the instructed person is ES2. The limit under single-fault condition is ES2. |
Touch Temperature | Handle and enclosure temperature are only measured during normal operation. Touch temperature can be measured at any ambient. The limits do not specify time. It simply states: “touch for a short period.” | Handle and enclosure temperature are to be measured during normal operation, abnormal and single fault conditions. Touch temperature limits are based on measurements in a room ambient of 77 deg. F (25 deg. C). Touch temperature requirements vary for ordinary, skilled, or instructed persons with prescribed safeguards for each category. The standard also takes into consideration anticipated duration of contact with accessible parts. |
Electrical Strength | Electrical strength (Hipot) test voltage is selected based on either Peak working voltages or Required withstand voltage. | Test voltage is determined based on the highest value among Transient Voltage, Peak working voltage and Temporary overvoltage as defined within the standard. If using DC test voltage, the standard requires the test to be performed in both polarities. |
What to Ask Before You Buy
When reviewing IT infrastructure—cabinets, PDUs, or enclosures—these questions cut through the confusion:
- Is the product UL Certified, or just tested to UL standards?
- Does it comply with UL 62368 (the current benchmark) or only UL 60950?
- Are all components certified to the latest 4th Edition of UL/CSA 62368-1?
- Has the vendor updated their full product line—including enclosures, PDUs, and supporting systems—to align with the new requirements?
- Can the vendor provide documentation that satisfies OSHA and insurance requirements?
Choosing products that are truly UL Certified isn’t about keeping regulators happy. It’s about protecting people, reducing risk, and ensuring your infrastructure can support the business without unexpected compliance gaps.
How CPI Can Help You Simplify Compliance
At Chatsworth Products (CPI), compliance isn’t treated as an afterthought. Our cabinets, eConnect intelligent PDUs, and RMR enclosures are designed and manufactured to meet or exceed UL 62368.
for IT infrastructure or to discuss meeting UL 62368 requirements in your next deployment.
