ashrae

Educational Resource

Industry Standards
& Testing

An overview of ASHRAE 52.2, ISO 16890, and other filtration standards your facility may need to reference for compliance or procurement specifications.

Key Standards

The Major Filtration Standards

ASHRAE 52.2

ASHRAE — American Society of Heating, Refrigerating & Air-Conditioning Engineers

Method of Testing General Ventilation Air-Cleaning Devices

The dominant standard in North America for rating air filters used in HVAC systems. ASHRAE 52.2 defines the MERV (Minimum Efficiency Reporting Value) scale and specifies the test procedures used to measure a filter's particle capture efficiency across 12 size ranges. Nearly all commercial and industrial air filter specifications in the US reference this standard.

MERV Scale HVAC Filters North America Particle Efficiency

ISO 16890

ISO — International Organization for Standardization

Air Filters for General Ventilation

The international standard that replaced EN 779 in 2018 for general ventilation filters. ISO 16890 classifies filters into four groups based on their efficiency against PM1, PM2.5, and PM10 particulate matter — the same size categories used in air quality regulations globally. It also includes a test for filter electrostatic discharge to provide a more realistic in-service performance picture.

ePM1 / ePM2.5 / ePM10 International Replaced EN 779 Discharge Test

ASHRAE 170

ASHRAE — Healthcare Facilities

Ventilation of Health Care Facilities

Defines minimum ventilation and filtration requirements for hospitals, surgical suites, isolation rooms, and other healthcare spaces. ASHRAE 170 typically mandates MERV 14 or higher final filters in critical areas, and is referenced by The Joint Commission, CMS, and state health departments when evaluating healthcare facility compliance.

Healthcare MERV 14+ Surgical / ISO Regulatory Compliance

ISO 29463

ISO — High Efficiency Air Filters

High Efficiency Filters and Filter Media for Removing Particles in Air

The international standard for HEPA and ULPA filters, covering classifications from H10 through U17. It defines test methods for filter media, separators, and assembled filter units using a Most Penetrating Particle Size (MPPS) approach. Cleanrooms and critical manufacturing environments reference ISO 29463 when specifying ceiling HEPA panels and exhaust systems.

HEPA / ULPA H10–U17 Cleanroom MPPS Testing

USP 797 / 800

USP — United States Pharmacopeia

Pharmaceutical Compounding — Sterile & Hazardous Preparations

USP 797 covers sterile compounding environments and requires ISO Class 5 or better air quality at the point of compounding. USP 800 extends requirements to hazardous drug handling. Both chapters specify HEPA filtration, pressure relationships, and environmental monitoring protocols enforced by state boards of pharmacy and accreditation bodies.

Pharmacy ISO Class 5 HEPA Required Hazardous Drugs

ISO 14644

ISO — Cleanrooms & Controlled Environments

Classification of Air Cleanliness by Particle Concentration

The global framework for cleanroom classification, defining ISO Classes 1 through 9 based on airborne particle counts per cubic meter. ISO 14644 replaced the older US Federal Standard 209E and is used across semiconductor, aerospace, medical device, and pharmaceutical manufacturing to specify and verify cleanroom performance, including HEPA filter installation and integrity testing.

Cleanroom Classes ISO 1–9 Particle Count Filter Integrity

Quick Reference

Standards at a Glance

Standard	Scope	Region	Filter Range	Who Uses It
ASHRAE 52.2	General ventilation — HVAC filters	North America	MERV 1–16	Commercial buildings, industrial facilities, hospitals
ISO 16890	General ventilation — international	Global	ePM1 / ePM2.5 / ePM10 / Coarse	International procurement, EU-compliant facilities
ASHRAE 170	Healthcare ventilation requirements	North America	MERV 7 minimum, MERV 14+ critical areas	Hospitals, surgical suites, outpatient facilities
ISO 29463	HEPA / ULPA filter testing	Global	H10–U17	Cleanrooms, critical manufacturing, healthcare
USP 797/800	Pharmaceutical compounding environments	United States	ISO Class 5 minimum	Hospital pharmacies, compounding facilities
ISO 14644	Cleanroom classification & testing	Global	ISO Class 1–9	Semiconductor, pharma, aerospace, medical devices
NAFA AGS-01	NAFA guide to air filtration installation	North America	All filter types	Facilities managers, filter distributors, contractors

By Industry

Which Standards Apply to You

Healthcare & Hospitals

ASHRAE 170
ASHRAE 52.2 (MERV ratings)
ISO 29463 (HEPA)
ISO 14644 (OR/cleanroom areas)
FGI Guidelines

Pharmaceutical & Compounding

USP 797 / USP 800
ISO 14644
ISO 29463
FDA cGMP requirements

Commercial Buildings

ASHRAE 52.2
ASHRAE 62.1 (ventilation)
ISO 16890 (international specs)
LEED / WELL building credits

Industrial & Manufacturing

ASHRAE 52.2
OSHA air quality regulations
NFPA (dust collection)
ISO 16890

Semiconductor & Microelectronics

ISO 14644 (Class 1–5)
ISO 29463 (HEPA/ULPA)
SEMI Standards

Food & Beverage

ASHRAE 52.2
FDA Food Safety Modernization Act
HACCP air quality requirements
ISO 14644 (processing areas)

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