CLEAN ROOMS &CLASSIFICATION OF CLEAN ROOMS

by: Amna Saeed

Pharm.D(2009-2014) (L.C.W.U)

A clean room (or cleanroom) is an enclosed space in which airborne particulates, contaminants, and pollutants are kept within strict limits.

CLEAN ROOM

WHY WE NEED CLEAN ROOM???

TO AVOID “CONTAMINATION”

CONTAMINATION

Contamination is a process or act that causes materials or surfaces to be soiled with contaminating substances.

Sources of Contamination:1:Facilities2:People3:Tool generated4: Fluids5: Product generated

1. FacilitiesWalls, floors and ceilingsPaint and coatingsConstruction material (sheet rock, saw dust etc.)Air conditioning debrisRoom air and vaporsSpills and leaks

2. PeopleSkin flakes and oilCosmetics and perfumeClothing debris (lint, fibers etc.)Hair

3. Tool GeneratedFriction and wear particlesLubricants and emissionsVibrationsmops and dusters

4. FluidsParticulates floating in airBacteria, organics and moistureFloor finishes or coatingsCleaning chemicalsDeionized water

5. Product generatedSilicon chipsQuartz flakesCleanroom debrisAluminum particles

HOW TO CONTROL CONTAMINATION???

Key Elements of Contamination Control

•HVAC system•HEPA•CLEANROOM ARCHITECTURE•LAMINAR FLOW CABINET•FILTERATION•CLEANING•CLEANROOM GARMENTS•HUMANS IN CLEANROOM•COMODITIES•COSMETICS•MEASUREMENTS & INSTRUMENTATION•ELECTROSTATIC DISCHARGE(ESD)

HVAC SYSTEM (heating, ventilation & air-conditioning) What can HVAC do?HVAC system performs four basic functions:

1. Control airborne particles, dust and micro-organisms – Thru air filtration using high efficiency particulate air (HEPA) filters.

They filter particles as small as 0.3 microns with a 99.97% minimum particle-collective efficiency

2. Maintain room pressure (delta P) –Areas that must remain “cleaner” than surrounding areas must be kept under a “positive” pressurization,

This is achieved by the HVAC system providing more air into the “cleaner” space than is mechanically removed from that same space.

3: Maintain space moisture (Relative Humidity) Humidity is controlled by cooling air to dew point temperatures or by using desiccant dehumidifiers.

4. Maintain space temperature –

Temperature can affect production directly or indirectly by fostering the growth of microbial contaminants on workers.

CLEANROOM ARCHITECTURE

This air flow is called laminar flow. The more restriction of air flow the more turbulence. Turbulence can cause particle movement.

Laminar flow cabinet

•Laminar flow principle involves double filteration of air through coarse Pre-filters (upto 5 microns) and HEPA filters (down to 0.3 microns) for filteration of Biological & Particulate contaminants.

•A constant uni-directional air flows either Horizontally or Vertically, is drawn from atmosphere and passed through pre and Hepa filters on to the work surface.

COMPONENTS OF LAMINAR FLOW CABINETPrefilters : Made of Washable synthetic material.Hepa Filters : Made of Microglass fibre with corrugated aluminium foil separators. Blower Units : A motor,with dynamically balanced blowers making the unit least vibrant with minimum noise level.Lighting : Fluorescent tube lights.Sterilization : Germicidal Ultra Violet (UV) tube.manometer : Pressure measuring device

TYPES OF LAMINAR FLOW CABINETS

CLEANROOM GARMENTS

The requirements for cleanroom garments will vary from location to location.

Gloves, face masks and head covers are standard in nearly every cleanroomenvironment

HUMANS IN CLEANROOMS

People are a major source of contamination in the cleanroom.

1. Body Regenerative Processes-- Skin flakes, oils, perspiration and hair.2. Behavior-- Rate of movement, sneezing and coughing.3. Attitude-- Work habits and communciationbetween workers.

Notice the number of particles produced per minute during these activities.

PEOPLE ACTIVITY NUMBER OF

PARTICLES/MIN(0.3 micron

and larger)

Motionless (Standing or

Seated)

100,000

Walking about 2 mph 5,000,000

Walking about 3.5 mph 7,000,000

Walking about 5 mph 10,000,000

Horseplay 100,000,000

COMMODITIES - Care is taken when selecting and using commodity items in cleanrooms. Wipers, cleanroom paper and pencils and other supplies that service the cleanroom should be carefully screened and selected

COSMETICS - Many cosmetics contain sodium, magnesium, silicon, calcium, potassium or iron. These chemicals can create damaging particles. Cleanroom managers may ban or restrict cosmetics in the cleanroomA recent mirror on a space telescope was fogged up from the cologne that was present in the cleanroom.

MEASUREMENT AND INSTRUMENTATION -

Some important measurements related to contamination control are particle count, air flow & velocity, humidity, temperature and surface cleanlinessELECTROSTATIC DISCHARGE (ESD)Moving air creates a charge. People touching surfaces or walking across the floor can create an electric charge.Special care is taken to use ESD protective materials to prevent damage from ESD. Cleaning managers should work with their personnel to understand where these conditions may be present and how to prevent them.

CLASSIFICATION OF CLEAN ROOMS

Clean rooms are classified by the cleanliness of their air.

•The method most easily understood and most universally applied is the one suggested in the earlier versions (A to D) of Federal Standard 209 of the USA.

•In this old standard the number of particles equal to and greater than 0.5 m m is measured in one cubic foot of air and this count used to classify the room.

Federal Standard 209This standard was first published in 1963 in the USA and titled "Cleanroom and Work Station Requirements, Controlled Environments“

Pharmaceutical Clean Room ClassificationFor the manufacture of sterile medicinal products four grades are given

Grade A: The local zone for high risk operations, e.g.filling zone, stopper bowls, open

ampoules and vials, making aseptic connections.Normally such conditions are provided

by a laminar air flow work station. Laminar air flow systems should provide an homogeneous air speed of 0.45 m/s +/- 20% at the working position.

Grade B: In case of aseptic preparation and filling, the background environment for grade A zone.

Grades C and D: Clean areas for carrying out less critical stages in the manufacture of sterile products.

Examples of operations to be carried out in the various grades are given in the table below

Additional microbiological monitoring is also required outside production operations, e.g. after validation of systems, cleaning and sanitization.

(NOTES: a) These are average values.(b) Individual settle plates may be exposed for less than 4 hours.(c) Appropriate alert and action limits should be set for the results of particulate and microbiological monitoring. If these limits are exceeded operating procedures should prescribe corrective action.

REFERENCES:1:http://www.mssl.ucl.ac.uk/www_cleanroom/cleanroom/cr_standards.html#pcc2:http://whatis.techtarget.com/definition/clean-room3:http://www.coastwidelabs.com/Technical%20Articles/Cleaning%20the%20Cleanroom.htm4:http://www.fda.gov/downloads/Drugs/.../Guidances/ucm070342.pdf