Storage Tank Emission Standards — The Current Technical Landscape

A controlled 2026 overview of the main technical standards and guidance documents that shape storage tank emission control.

Storage-tank emission control sits across several disciplines. No single standard covers tank design, emission estimation, venting, inspection, fire protection and regulatory BAT. The practical task is to understand which document governs which part of the problem and where owner or legal requirements add another layer.

This overview is controlled to 5 October 2026. It deliberately avoids reproducing proprietary standard text. Always confirm the project edition and contractual or statutory adoption before applying a requirement.

1. API 650 — tank and floating-roof design

API 650 is the central API standard for welded storage tanks and includes requirements for internal and external floating roofs and aluminium dome roofs through its appendices. API’s publication notices show a 14th Edition release in August 2025.

For emission-control projects, API 650 is important because the roof and seal must remain structurally and operationally compatible with the tank. It is not an emission-inventory method and should not be used as a substitute for API MPMS Chapter 19 or AP-42.

2. API MPMS Chapter 19 — evaporation-loss estimation

The API Manual of Petroleum Measurement Standards Chapter 19 series contains the industry methods for estimating evaporative losses and for establishing several loss factors. API’s 2025 catalogue lists MPMS 19.2, Evaporative Loss from Floating-Roof Tanks, as Fourth Edition (2020). API committee records show a reaffirmation ballot in 2025.

Separate Chapter 19.3 parts address test methods for rim seals, deck fittings and deck seams. This is an important distinction: the calculation method and the test method for a component factor are related but not the same document.

3. EPA AP-42 Chapter 7.1 and TANKS

EPA finalised a revised AP-42 Chapter 7.1 for organic liquid storage tanks in October 2024. The chapter provides public emission-estimation procedures and tank descriptions. EPA’s TANKS Version 5 application implements the AP-42 methodology; the current TANKS 5.3 release dates from July 2026.

AP-42 is widely used beyond the United States for inventories and screening because it is accessible and transparent. Legal acceptance still depends on the jurisdiction and permit.

4. API 2000 — venting

API 2000 addresses venting of atmospheric and low-pressure storage tanks. API’s standards plan lists the 8th Edition dated 13 August 2026. It is central whenever emission reduction changes vent paths, P/V settings, blanketing or connection to a vapour-control system.

Emission reduction must remain inside the tank’s allowable pressure and vacuum envelope. Venting is therefore both an emissions and integrity interface.

5. EEMUA 213 — emission reduction

EEMUA 213 is dedicated to prevention and control of VOC emissions from tanks containing oil or chemical products. Its structure begins with the source of emissions, uses true vapour pressure in tank-type selection and then considers treatment of escaping vapour where source reduction does not achieve the required result.

It is particularly useful because it connects tank configuration, practical emission-control measures and operating experience rather than focusing on one equipment type.

6. EEMUA 159 and API 653 — integrity

Emission controls operate on an asset whose geometry and condition change over time. EEMUA 159 and API 653 therefore matter even when the project objective is environmental. EEMUA released Edition 6 of Publication 159 on 3 April 2025. The edition expands integrity assessment, degradation, inspection and modern inspection technologies.

EEMUA describes Publication 159 as complementary to API 653. For emission-control work, the key point is that tank settlement, shell distortion, corrosion and roof condition can directly affect floating-roof and seal performance.

7. EN 14015, NFPA and other interfaces

EN 14015 remains a major European tank design framework. Fire-protection standards such as NFPA 11 become relevant where seals, foam dams, floating roofs or dome conversions interact with foam application. Hazardous-area, electrical and lightning requirements may introduce further standards.

These documents should be treated as an interface map rather than a shopping list. The applicable set depends on location, tank type, product and owner requirements.

8. BREF and national guidance

The European Emissions from Storage BREF was formally adopted in July 2006 and remains the listed cross-sector BREF for storage. National systems then translate BAT, environmental permitting and safety requirements into local obligations. In the Netherlands, PGS 29:2022 version 1.1 (April 2026) is a key safety reference for aboveground storage of flammable liquids in vertical cylindrical tanks.

A technical standard does not automatically become law merely because it exists. Determine whether it is incorporated by regulation, permit, contract, owner standard or recognised good practice.

9. Keep a standards register

Every emission project should maintain a short standards register containing document title, edition/date, applicability, adoption route and any owner deviation. This avoids one of the most common causes of technical confusion: different parties quietly working to different editions.

References and technical basis

Standards and regulations change. Confirm the edition, legal applicability and permit conditions for the tank, product and jurisdiction before design or compliance decisions are made.