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Clean room classification British standard 5295:1989

British Standard 5295:1989

This standard is available from:
B S I Standards
389 Chiswick High Road
London W44 AL
Tel 0181 996 9000
Fax 0181 996 7400
The British Standard is in five parts. These are:
Part 0 - General introduction and terms and definitions for cleanrooms and clean air devices. (4 pages)
Part 1 - Specification for cleanrooms and clean air devices. (14 pages)
Part 2 - Method for specifying the design, construction and commissioning of cleanroom and clean air devices. (14 pages)
Part 3 - Guide to operational procedures and disciplines applicable to cleanrooms and clean air devices. (6 pages)
Part 4 - Specification for monitoring cleanrooms and clean air devices to prove continued compliance with BS 5295. (10 pages)
The contents of the above parts are as follows:
Part 0 - 'General introduction, terms and definitions for cleanrooms and clean air devices'
The definitions have been drawn together and presented in this section. This part also provides a basic introduction to the main parts of the standard, particularly for those unfamiliar with cleanrooms or the standard itself.
Part 1 - 'Specification for cleanrooms and clean air devices'
The Standard contains ten classes of environmental cleanliness. Shown in Table 4 are the classes given in the standard. All classes have particle counts specified for at least two particle size ranges to provide adequate confidence over the range of particle size relevant to each class.
Some classes of rooms, except for 0.3 m m particles, have an identical specification. For example, Class F is equivalent to Class E except for the 0.3 m m particle specification. This is deliberate, as many users, e.g. pharmaceutical manufacturing, do not wish to be associated with the small particle technology that is not appropriate to their industry.

Table 4 BS 5295 Environmental cleanliness classes
 

Maximum permitted number of particles per m^3 (equal to, or greater than, stated size)Maximum floor area per sampling position for cleanrooms (m^2)Minimum pressure difference*
Class of environmental cleanliness0.3 m m0.5 m m5 m m10 m m 25 m mBetween classified areas and unclassified areas (Pa)Between classified area and adjacent areas of lower classification (Pa)
C
100
35
0
NS
NS
10
15
10
D
1 000
350
0
NS
NS
10
15
10
E
10 000
3 500
0
NS
NS
10
15
10
F
NS
3 500
0
NS
NS
25
15
10
G
100 000
35 000
200
0
NS
25
15
10
H
NS
35 000
200
0
NS
25
15
10
J
NS
350 000
2 000
450
0
25
15
10
K
NS
3 500 000
20 000
4 500
500
50
15
10
L
NS
NS
200 000
45 00
5 000
50
10
10
M
NS
NS
NS
450 000
50 000
50
10
NA
BS 5295:1989 identifies three states of operation similar to FS208E:
  • as built - on completion, prior to moving in
  • unmanned - operational but not in use
  • manned - in full operational use
  • Also given in the specification of Part 1 are other requirements for cleanrooms to comply with. These are:
  • minimum pressure difference between the cleanroom and adjacent areas (see Table 4)
  • filter installation test leakage
  • freedom of leakage from construction joints or openings
Testing to satisfy the requirements of Part 1 of the British Standard is discussed later in this document in that section which deals with the testing and validation of cleanrooms.
Part 2 - 'Method for specifying the design, construction and commissioning of cleanrooms and clean air devices'
A major consideration in the rewrite of BS 5295 was to ensure its usefulness as a purchase and operational specification and as supporting documentation to a contract. Part 2 has therefore been restructured into a format which enables a purchaser to specify what type of room or device is required and, where relevant, how it is to be achieved. To assist with its use as part of contractual documentation it has been given specification status, i.e. it is mandatory.
Part 3 - 'Guide to operational procedures and disciplines applicable to cleanroom and clean air devices'
This incorporates guidance for those drawing up procedures for personnel, operations, cleaning, garments and garment laundering.
Part 4 - 'Specification for monitoring cleanrooms and clean air devices to prove continued compliance with BS 5295: Part 1'
Cleanroom and clean air equipment standards have for many years defined classes of cleanliness and how they are to be assessed. However there has never been any requirement to test a cleanroom at any point in its often very long lifetime, other than at the time of handover from supplier to purchaser. Once accepted from the supplier, the facility then repaid its capital cost, over a life span of ten to twenty years, sometimes without ever being tested. Yet over this period customers were provided with products which were stated to be 'produced under Class X'. This can no longer be the case.
The tests specified are those contained in Part 1, thus providing a continuity back to the original purchase specification. The intervals between tests are related to the class of room or device and are given later in this manual in that section relating to the validation and testing of cleanrooms.
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