Environmental microbiological control of air (sedimentation)

Technical information

Utility

• Cleanrooms or white rooms are specially designed to ensure low levels of contamination and have environmental parameters strictly controlled by regulations. Environmental microbiological controls allow us to know the microbiological conditions of the facilities, equipment, and operators, in order to ensure compliance with regulations.

• The most common sources of microorganisms found in a facility are:
   

• The personnel entering the facility.

• The materials entering the facility.

• The air filtration system (HEPA filters in cleanrooms).

• The elements that can become contaminated with microorganisms and pose a risk are:

• Air: Environmental air or laminar flow hoods.

• Surfaces: Floors, walls, tables, handles, etc.

• Equipment: Incubators, laminar flow hoods, centrifuges, refrigerators, microscopes, balances, etc.

• Clothing: Gloves, operator's clothing.

• The definition of environmental control points and frequencies is based on an environmental risk analysis conducted before the start of activities in a facility, where the rooms, equipment, materials, workflows, number of personnel, and other factors are reviewed.

Method

Plates used for environmental microbiological control are shown in Table 1. The plates contain suitable culture media for the growth of bacteria and fungi. They also include agents that neutralize the possible presence of disinfectants to prevent interference with the growth of microorganisms.

Before using a batch of plates, a growth promotion test is conducted to verify if that batch of plates allows the growth of microorganisms.

Table 1. TSA: Tryptone Soya Agar medium. SDA: Sabouraud Dextrose Agar medium

The most suitable techniques for monitoring points in environmental microbiological control are shown in Table 2:

Table 2: Techniques used to sample different elements.

The sedimentation technique involves exposing a plate to the air in the risk area of the room or inside the laminar flow hood for a maximum of 4 hours. Sampling is done while the operator is active to have environmental results in operation. Two plates are placed, one for fungi and one for bacteria.

The plates should be sent to the Microbiology Laboratory as soon as possible after sampling. There, they are received and incubated:

• TSA plates are incubated at 32.5°C (30°C - 35°C) for 3-5 days for bacteria

• SDA plates are incubated at 22.5°C (20°C - 25°C) for 5-7 days for fungi.

A negative internal control is also included to ensure that the plates are not contaminated at the Microbiology

Specimen information

Sample: Air (sedimentation)

Tubes: 90 mm TSA plate for bacteria and SDA for fungi

Stability: Transport immediately to the laboratory. If not possible, store at room temperature for a maximum of 4 hours.

Transport instructions: Room temperature.

Reasons for rejection: Improperly sealed plate, unidentified, etc.

Administrative information

BST Code: 60001 (bacteria) and 60005 (fungi)

Previous BST Code: 7535 (bacteria) and 7552 (fungi)

Test Description: Air bacteria control (settling), Air fungi control (settling)

Synonyms: Air settling CMA, Environmental air microbiological control (settling)

Section: Microbiology

BST Rate: Check the updated rates here.

Profiles

Not applicable

References

• Guide to the quality and safety of tissues and cells for human application. 5th edition EDQM, 2022

• Farmacopea Europea 11ena edició, 2023

• ISO 171330-1:2008 Calidad ambiental en interiores. Parte 1: Diagnóstico de calidad ambiental interior.

• ISO 171330-2:2014 Calidad ambiental en interiores. Parte 2: Procedimientos de inspección de calidad ambiental interior.

• ISO 171330-3:2014 Calidad ambiental en interiores. Parte 3: Sistema de gestión de los ambientes interiores.

• ISO 171340:2020 Validación y cualificación de salas de ambiente controlado en hospitals

• Norma EN ISO 14644-1. Clasificación de sala limpias.

• Estándares en hemoteràpia CAT

• FACT-JACIE International Standards for Cellular Therapy Product Collection, Processing, and Administration.

• NETCORD-FACT International Standards for Cord Blood Collection, Banking, and Release for Administration.

• NCF: Guía de Normas de Correcta Fabricación de Medicamentos de Uso Humano y Veterinario. Anexo 1

• NCF Parte IV: Directrices sobre normas de correcta fabricación específicas para Medicamentos de Terapia Avanzada.

• GpG. Directrices de Buenas Prácticas - Guía para la preparación, uso y control de calidad de los componentes sanguíneos.

• Real Decreto-ley 9/2014, de 4 de julio, por el que se establecen las normas de calidad y seguridad para la donación, la obtención, la evaluación, el procesamiento, la preservación, el almacenamiento y la distribución de células y tejidos humanos y se aprueban las normas de coordinación y funcionamiento para su uso en humanos.

Quality

BST holds ISO 9001, ISO 14001, and OSHAS 18001 quality certifications, as well as the European Excellence 500+ seal. BST is accredited by CAT, JACIE-FACT, FACT-NETCORD, and EFI, and complies with Good Manufacturing Practice (GMP) and Good Distribution Practice (GDP) guidelines.