What is GMP Class A and B Cleanroom Environments?

Author:Jason Peng
Cleanroom Engineering Technology Manager of Deiiang Company.

Product R&D Manager of GDC Inc. Cleanroom Equipment Manufacturing Company.

Executive Director of Guangdong Cleanroom Industry Association of China.

Engaged in R&D of related products for 15 years, with rich relevant technical experience
2024-11-17 | Visits:

GMP Class A and B Cleanroom Environments

Specialized Environments for Pharmaceutical Manufacturing

Introduction to GMP Cleanrooms

GMP (Good Manufacturing Practice) Class A and Class B cleanrooms are specialized environments designed to ensure the highest level of cleanliness and control during the manufacturing of pharmaceutical products, particularly sterile drugs and medical devices. These environments follow strict guidelines to prevent contamination, ensuring that products are produced safely and comply with regulatory requirements.

Cleanroom Classifications according to EU GMP

CleanRoom Classifications according to EU GMP

GMP Class A CleanRoom Environment

A GMP Class A CleanRoom represents the most stringent standards for air cleanliness. This environment is typically used for processes that directly affect the sterility of pharmaceutical products, such as aseptic filling and sterile drug preparation.

According to the EU GMP Annex 1 and ISO 14644-1, Class A modular cleanrooms must meet ISO 5 standards, meaning that the allowable particle concentration of 0.5 microns or larger is restricted to ≤3,520 particles per cubic meter.

GMP Class b CleanRoom Environment

A GMP Class B cleanroom is slightly less stringent than Class A but still requires a high level of cleanliness. Class B environments are used for processes that support aseptic filling or other critical pharmaceutical processes but do not directly come into contact with the sterile products.

According to EU GMP Annex 1, these rooms must meet ISO 6 standards for particle count, which allows up to 35,200 particles per cubic meter for particles of 0.5 microns or larger.

Key Differences Between GMP Class A and Class B Cleanrooms

Feature	GMP Class A	GMP Class B
Particle Count (0.5 microns or larger)	≤3,520 particles/m³ (ISO 5)	≤35,200 particles/m³ (ISO 6)
Primary Usage	Critical processes (aseptic filling, sterile preparation)	Supporting processes, buffer zones
Airflow System	Unidirectional airflow	Turbulent airflow with higher exchange rates
Filtration Efficiency	Higher efficiency (HEPA/ULPA)	Standard HEPA/ULPA filtration

Features and Control Measures

Both GMP Class A and Class B cleanrooms are equipped with advanced air filtration systems, including HEPA or ULPA filters, to ensure the removal of airborne particles. Airflow patterns and pressure differentials are closely monitored to maintain cleanliness, and strict gowning and hygiene protocols are followed to minimize human contamination.

Filtration

Both classes use HEPA or ULPA filters,

but Class A typically requires higher filtration efficiency.

Airflow

Class A uses unidirectional airflow,

while Class B may use turbulent modular clean room airflow with higher air exchange rates.

Pressure

Both Class A and B require positive pressure,

to prevent contamination from surrounding environments.

Applications of GMP Class A and B Cleanrooms

Class A and Class B Cleanrooms are found primarily in the pharmaceutical and biotechnology industries, where the production of sterile products is required. Class A is used for the most sensitive processes, while Class B is used in secondary processes that support or are adjacent to Class A.

GMP Cleanroom Classifications: Understand Class A, B, C And D

• Class A Applications

Sterile drug manufacturing
Aseptic filling processes
Sterile preparation areas
Direct contact with sterile products
Critical aseptic operations

• Class B Applications

Clean areas supporting Class A
Compounding and preparation areas
Buffer zones between Class A and lower grades
Non-critical sterile support processes
Equipment preparation for Class A areas

Relevant Standards and Guidelines

EU GMP Annex 1

Provides specific requirements for cleanroom environments in the pharmaceutical industry, outlining the necessary classifications for aseptic manufacturing.