ISO 10121-3-2022 PDF

Full title and description

ISO 10121-3:2022 — Test methods for assessing the performance of gas-phase air cleaning media and devices for general ventilation — Part 3: Classification system for GPACDs applied to treatment of outdoor air. This part defines a classification system for single‑pass gas‑phase air cleaning devices (GPACDs) used to treat outdoor air supplied to general ventilation systems; it identifies four reference pollutants (ozone, sulfur dioxide, nitrogen dioxide and toluene) and specifies three duty levels (Light Duty, Medium Duty, Heavy Duty) for each pollutant to help compare molecular filtration performance in outdoor‑air applications.

Abstract

ISO 10121-3:2022 establishes a practical, repeatable classification scheme that enables comparison of molecular (gas‑phase) air cleaning devices for outdoor‑air treatment in general ventilation. The standard sets reference test pollutants and assigns dose‑based duty levels (LD, MD, HD) for each pollutant, allowing users to predict relative lifetime and capacity under defined test conditions. It is intended to complement particulate classification methods such as ISO 16890‑1 by addressing molecular contaminants rather than particles.

General information

• Status: Published (International Standard).
• Publication date: October 2022 (edition 1, 2022‑10).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 91.140.30 (Air treatment and ventilation systems).
• Edition / version: Edition 1 (2022).
• Number of pages: 24 pages (ISO publication information).

(Core bibliographic facts from the ISO record for ISO 10121‑3:2022.)

Scope

This part of ISO 10121 specifies a classification system and reference test pollutants for GPACDs that supply single‑pass outdoor air to general ventilation systems affected by urban and long‑distance outdoor pollution. It is limited to molecular contaminants represented by ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2) and toluene (representative VOC). The standard explicitly excludes GPACDs used in recirculation applications or for treatment of air dominated by indoor sources, and it is not intended for specialized applications such as pharmaceutical, microelectronic, nuclear, homeland security or military filtration.

Key topics and requirements

• Introduction of a standardized classification scheme for GPACDs based on dose capacity per unit face area and average efficiency over defined test conditions.
• Specification of four reference pollutants: ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2) and toluene (VOC).
• Three duty‑level classes — Light Duty (LD), Medium Duty (MD) and Heavy Duty (HD) — assigned per pollutant; MD ≈ 4× the LD capacity and HD ≈ 16× the LD capacity for the same nominal efficiency level.
• Definition of dose metrics (moles or grams per unit GPACD face area) used to predict lifetime and capacity under the specified test conditions. Example dose targets per class are given in the classification tables.
• Requirement that comparisons and ratings are valid only when filters are tested under identical nominal conditions (flow, temperature, humidity, test configuration). Test concentrations used are much higher than typical ambient concentrations to accelerate testing.

Typical use and users

Primary users are molecular filter manufacturers, HVAC and indoor‑air systems designers, air‑quality consultants, building engineers and facility managers who need a repeatable way to specify and compare GPACDs for outdoor‑air treatment in general ventilation. The standard is used to communicate product capacity classes, inform selection of molecular filtration in building ventilation design, and support procurement/specification language.

Related standards

ISO 10121‑3:2022 is part of the ISO 10121 series on test methods for gas‑phase air cleaning media and devices (other parts include ISO 10121‑1 and ISO 10121‑2). It is intended to complement particulate filtration standards used in ventilation (for example ISO 16890‑1) and may be referenced alongside national/adopted versions (e.g., BS EN ISO 10121‑3) and related HVAC/IAQ standards when specifying whole‑system performance.

Keywords

ISO 10121‑3, gas‑phase air cleaning, GPACD, molecular filters, activated carbon, LD/MD/HD classification, ozone, SO2, NO2, toluene, outdoor air treatment, general ventilation, filter lifetime, dose capacity.

FAQ

Q: What is this standard?

A: ISO 10121‑3:2022 is an international standard that defines a classification system and reference test pollutants for gas‑phase air cleaning devices used to treat outdoor air supplied to general ventilation systems.

Q: What does it cover?

A: It covers test‑based classification of GPACDs for four reference pollutants (ozone, sulfur dioxide, nitrogen dioxide and toluene) and assigns duty levels (Light, Medium, Heavy) based on dose per unit face area and average efficiency under specified test conditions. It does not set indoor‑air exposure limits nor cover recirculation or specialized industrial/military applications.

Q: Who typically uses it?

A: Filter and air‑cleaner manufacturers, HVAC system designers, consultants, building and facility engineers, and procurement/specification professionals use the standard to compare and specify molecular filtration for outdoor‑air treatment in general ventilation.

Q: Is it current or superseded?

A: As published in October 2022 (Edition 1), ISO 10121‑3:2022 is a current published International Standard. Users should check national adoption records or the ISO catalogue for any subsequent amendments or withdrawals.

Q: Is it part of a series?

A: Yes — it is part of the ISO 10121 series addressing test methods for gas‑phase air cleaning media and devices; earlier parts cover test methods and test rigs for molecular filter media and devices.

Q: What are the key keywords?

A: Key keywords include molecular filtration, GPACD, gas‑phase air cleaning, activated carbon, LD/MD/HD classification, ozone, SO2, NO2, toluene, outdoor air, general ventilation, dose capacity, and filter lifetime.