UL 142 and UL 2085 are both standards used for aboveground storage tanks for flammable and combustible liquids, but they are not the same.
UL 142 applies to steel aboveground tanks and establishes requirements for the design, fabrication, marking, and production testing of aboveground steel tanks. UL explains that UL 142 includes requirements manufacturers use to design and fabricate aboveground steel tanks, and that 100% of each listed primary and secondary containment tank must be production tested for leakage.
UL 2085 applies to protected aboveground tanks. These tanks include additional performance features such as enhanced fire resistance, integral secondary containment, and impact protection.
In simple terms, UL 142 is the baseline standard for many aboveground steel storage tanks. UL 2085 is used when the project requires a protected aboveground tank with added fire and physical damage protection.
Quick Comparison Table
| Topic | UL 142 | UL 2085 |
|---|---|---|
| Full standard context | Steel aboveground tanks for flammable and combustible liquids | Protected aboveground tanks for flammable and combustible liquids |
| Primary tank type | Aboveground steel storage tanks | Protected aboveground storage tanks |
| Core purpose | Establishes construction, fabrication, marking, and production test requirements for aboveground steel tanks | Establishes protected tank requirements with enhanced fire resistance, impact protection, and secondary containment |
| Fire protection | Does not make the tank a protected tank by itself | Includes enhanced fire resistance requirements |
| Impact protection | Not the defining purpose of the standard | Includes physical damage / impact protection requirements |
| Secondary containment | UL 142 tanks may be single-wall, secondary containment, or diked type depending on configuration | UL 2085 protected tanks include integral secondary containment |
| Common use | General aboveground storage of stable flammable and combustible liquids where a protected tank is not required | Higher-protection applications, including locations where codes, AHJs, specifications, or risk conditions call for a protected tank |
| Relationship | Often the starting point for aboveground steel tank construction | A protected tank standard that may incorporate UL 142 construction requirements for the primary tank |
| Key question | Is a listed aboveground steel tank sufficient for this application? | Does the project require a protected aboveground tank? |
What Is UL 142?
UL 142 is the standard commonly associated with aboveground steel storage tanks for flammable and combustible liquids. UL describes UL 142 as covering steel primary, secondary, and diked-type atmospheric storage tanks intended for aboveground applications.
UL 142 tanks may be used in many common fuel and petroleum storage applications, including generator fueling, fleet fueling, industrial sites, commercial fueling, and other aboveground tank installations where the applicable code, authority having jurisdiction, and project specification allow a UL 142 tank.
A UL 142 listing does not automatically mean the tank is a protected tank. It means the tank has been designed, fabricated, marked, and tested under the UL 142 listing requirements.
What Is UL 2085?
UL 2085 is the standard for protected aboveground tanks for flammable and combustible liquids. UL describes UL 2085 tanks as protected tanks with enhanced fire resistance, integral secondary containment, and impact protection.
STI/SPFA’s FIREGUARD® resource identifies FIREGUARD® as a UL 2085 listed protected tank with ballistics and impact protection per UL 2085, and notes that both the inner and outer steel tanks are built to UL standards.
UL 2085 tanks are typically selected when a project requires more protection than a standard aboveground tank, especially where fire exposure, vehicle impact, proximity to property lines or buildings, fueling operations, or AHJ requirements are important considerations.
Key Differences Between
UL 142 and UL 2085
Baseline Tank Standard vs. Protected Tank Standard
The most important difference is that UL 142 is a standard for aboveground steel tanks, while UL 2085 is a standard for protected aboveground tanks.
A UL 142 tank may be appropriate for many aboveground fuel storage applications. A UL 2085 tank is intended for situations where additional protection is required or preferred.
Fire Exposure Performance
UL 2085 includes fire exposure performance requirements that are not the same as a standard UL 142 tank listing. STI/SPFA’s FIREGUARD® testing explanation notes that UL 2085 includes a full-scale fire test simulating a hydrocarbon pool fire.
This is one of the main reasons UL 2085 tanks are commonly used in more restrictive or higher-risk aboveground fuel storage applications.
Impact and Physical Damage Protection
UL 2085 protected tanks include impact protection requirements. UL characterizes UL 2085 tanks as offering impact protection, along with enhanced fire resistance and integral secondary containment.
UL 142 is not primarily an impact-protection standard. A UL 142 tank may still require external protection such as bollards or other safeguards depending on the installation and AHJ requirements.
Secondary Containment
UL 142 includes steel primary, secondary, and diked-type tank configurations. That means a UL 142 tank can be single-wall, double-wall, or diked depending on the listed design and project specification.
UL 2085 protected tanks include integral secondary containment as part of the protected tank system.
Relationship Between the Standards
UL 2085 and UL 142 are related. STI/SPFA’s FIREGUARD® testing explanation states that UL 2085 requires the primary tank to be constructed per UL 142 requirements.
This is an important distinction: a UL 2085 protected tank may include UL 142 construction requirements for the primary tank, but a UL 142 tank is not automatically a UL 2085 protected tank.
Emergency Venting
Venting requirements are also important. STI/SPFA’s emergency vent guidance states that UL 2085 tanks are required to be shipped from the fabricator with a UL Listed emergency vent on the primary and interstitial vent openings.
Because venting is a common inspection and AHJ review item, emergency vent selection should be addressed early in the project.
When UL 142 Tanks Are Typically Used
UL 142 tanks are commonly used for aboveground storage of stable flammable and combustible liquids when the applicable code, AHJ, site conditions, and project specification do not require a protected tank.
| Application Need | Why UL 142 May Fit |
|---|---|
| Standard aboveground fuel storage | UL 142 is commonly used for aboveground steel storage tanks |
| Generator fueling | UL 142 tanks may be used where accepted by code and AHJ |
| Fleet or commercial fueling | UL 142 may be appropriate depending on location, capacity, setbacks, containment, and protection requirements |
| Industrial storage | UL 142 may fit applications involving compatible stable flammable or combustible liquids |
| Double-wall containment | UL 142 tanks may be available in secondary containment configurations |
| Cost-sensitive applications | UL 142 may be selected when a protected tank is not required |
When UL 2085 Tanks Are Typically Used
UL 2085 tanks are commonly used when additional tank protection is required by code, AHJ interpretation, owner preference, insurance requirements, project specification, or site conditions.
| Application Need | Why UL 2085 May Fit |
|---|---|
| Higher fire exposure concern | UL 2085 includes enhanced fire resistance requirements |
| Vehicle impact concern | UL 2085 includes impact protection requirements |
| Integral secondary containment | Protected tanks include secondary containment as part of the listed system |
| Fueling near buildings, property lines, or traffic | AHJs may require or prefer protected tanks in more restrictive locations |
| Aviation or critical fuel storage | UL 2085 tanks are often used in higher-value or higher-consequence fueling systems |
| Owner risk management | Owners may choose UL 2085 for added protection even when not explicitly required |
Why UL 2085 May Be Required or Preferred
UL 2085 may be required when the fire code, local AHJ, project specification, site layout, or owner’s risk-management approach calls for a protected aboveground tank.
Common triggers may include:
| Trigger | Why It Matters |
|---|---|
| AHJ requirement | The authority having jurisdiction may require a protected tank based on local code interpretation |
| Fire code context | Protected tanks may be required or preferred in certain aboveground fuel storage arrangements |
| Setbacks or site constraints | Tight sites may raise fire exposure, impact, or separation concerns |
| Vehicle traffic | Impact protection may be an important design consideration |
| Critical fuel supply | Generator, aviation, emergency response, or mission-critical sites may prefer added protection |
| Insurance or owner standards | Some owners or insurers may specify UL 2085 as a risk-reduction measure |
Common Confusion Points
Is UL 2085 just a stronger version of UL 142?
Not exactly. UL 2085 is a protected tank standard. It includes additional fire, impact, and secondary containment performance requirements. UL 142 is the baseline aboveground steel tank standard.
Is every UL 142 tank also UL 2085?
No. A tank listed to UL 142 is not automatically listed to UL 2085. UL 2085 requires additional protected tank performance features.
Does UL 2085
include UL 142?
UL 2085 protected tanks are related to UL 142 construction requirements. STI/SPFA’s FIREGUARD® testing explanation states that UL 2085 requires the primary tank to be constructed per UL 142 requirements.
Are UL 142 tanks
double-wall?
They can be, but they are not always double-wall. UL 142 covers steel primary, secondary, and diked-type atmospheric storage tanks.
Is UL 2085 always required for aboveground fuel tanks?
No. UL 2085 is not automatically required for every aboveground fuel tank. Whether UL 2085 is required depends on the applicable code, AHJ, tank location, stored liquid, capacity, site conditions, and project specification.
FAQs
Related Resources
UL 142 vs. UL 2085 Aboveground Storage Tanks
FIREGUARD®
Aboveground Storage Tank FAQ
Selecting an Emergency Vent for Shop Fabricated UL 142 & 2085 Aboveground Storage Tanks
F921®
STI Standards
Aboveground Shop-Fabricated Storage Tanks Member Directory
STI Technologies
Trying to determine whether your project requires a UL 142 or UL 2085 aboveground storage tank?
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