Clean Room Testing and Validation Services

Clean Room Testing and Validation Services
There are varying standards that apply to different classes of clean room, and how to carry out the cleanroom testing in a consistent and reliable way.  The Cleanroom Validation Standards are as follows:

ISO 1 class (No GMP Classification)

ISO 1 class is the cleanest, with an allowable particle count of just 10 per m3 at 0.1µm and just 2 per m3 at 0.2µm. This type of facility is very uncommon would be used only for the most sensitive research and development work involving, for instance, semi-conductors or nano-technology.  ISO Class 1 is significantly cleaner than the cleanest cleanroom specified by either the BS 5295 standard or the EU GMP standard, whose highest grade cleanrooms equates approximately to ISO Class 3 and ISO Class 5 respectively.

ISO Class 5 (GMP classification A and B)

ISO Class 5 facility is considered a high grade cleanroom and is typically required for aseptic applications such as sterile filling of pharmaceutical products into containers, for example. It allows up to 100,000 particles of 0.1µm and up to 3520 particles of 0.5µm per m3. An ISO Class 5 cleanroom equates to EU GMP class A and B, and BS 5295 Class E and F.

ISO Class 7 (GMP classification D)

An ISO Class 7 facility can have an unrestricted number of small particles (0.1µm to 0.3µm) but must have no more than 352,000 particles at size 0.5µm and no more than around 2,900 particles at 5µm. This equates to an EU GMP Class C facility or a BS 5295 Class J facility and would typically be used for sub-sterile pharmaceutical processes.

ISO Class 8 (GMP classification D)

An ISO Class 8 cleanroom is permitted up to 3,520,000 particles at size 0.5µm and 293,000 particles at size 5µm, equating approximately to EU GMP Class D or BS 5295 Class K. This level of cleanliness would be used for less sensitive applications where sterility is not an issue but where it makes general sense to maintain a good level of hygiene, such as packaging or storage of pharmaceuticals.

Clean Room Testing and Validation Services


It is worth noting that these classes provide a starting point for clarifying what standards are required for a particular cleanroom, they do not always give the full picture. Actual standards are set by a combination of different factors relating to the specific application, and may fall somewhere between the levels specified in these standards.

APT Cleanroom Testing is an independent  clean room services contractor, qualified to carry out clean room validation for all classes of facility, to ensure that not only are your facilities validated and maintained to the required levels, but that your customers and clients can have complete trust in the quality of your clean room processes.

I hope the above information was informative. If you would like some more information in regards to our cleanroom testing service please don’t hesitate to contact Darren directly on 07775623464.

APT Cleanroom Testing provides clients with a reliable and proactive clean room testing service. If you would like to know more about our particulate testing service and/or  HEPA filter testing service to cleanrooms, please don’t hesitate to contact us at:

Our Cleanroom Testing Process

Our Cleanroom Testing Process

To ensure that your clean room environment is working effectively a number of factors relating to the air supply coming from your ventilation need to be tested. These tests apply to every type of clean room, whether used for the manufacture of pharmaceutical products, sterile and aseptic or food production.

We will need to test the quantity of air to ensure that there is enough to dilute or remove any contamination generated within your clean room, and we will need to test the quality of the air to ensure that it is not adding to any contamination, rather than removing it.


We also need to test the flow of the air to ensure that it is moving from clean to less clean areas, minimising the movement of any contaminated air into your clean area, and also to ensure there are no areas of the room with high concentrations of pollutants.

In order to carry out these cleanroom tests, for every clean room we are working in, we will measure and check:

  1. Air Tightness Testing – to check your room envelope is air tight and not leaking.
  1. Air Supply and Extract Quantities – If your air supply is unidirectional we will measure and record the air velocity.
  1. Differential Pressure – Here we will be testing to ensure that the air in your clean room always moves from clean to less clean areas.
  1. Filter Installation Leak Testing – Your ventilation system’s high efficiency particulate air (HEPA) filter can be tested to ensure their integrity.
  1. Containment Leak Testing – We will check the construction of your clean room to ensure that no airborne contamination can occur via leaks from higher pressure work areas adjacent to it.
  1. Air Movement Control – Studying the movement of the air within your clean room we will check that there is sufficient air movement to dilute or remove pollutants, preventing any contamination build-up.
  1. Room Recovery – Reviewing the effectiveness of airflow we will measure how quickly a clean room recovers to its normal operating cleanliness following a release of particulate contaminant.
  1. Airborne particles and microbial concentrations – Finally, we will carry out measurements to ensure that the concentration of particles and micro-organisms is compliant with the specification set out for your clean room.
  1. Temperature, Relative Humidity – We may also need to carry out tests on temperature, relative humidity, and the heating and cooling capabilities of the room, as well as noise, lighting and vibration levels.

If you have a clean room that requires particulate monitoring or any of the above testing then please get in touch with us as soon as possible as we should be able to offer you an expedient solution for your cleanroom testing and cleanroom certification.


We can also offer maintenance programmes to ensure your cleanroom is in compliance with the corresponding ISO standards– it’s why we place such emphasis on the process of ‘expert intervention’.

Please contact us at:  or phone Darren directly on: 07775623464.

Acoustic Terminology M-S

Acoustic Terminology M-S

Our previous blog explained the  of acoustic terminology, this blog covers  M-S.


This is a physical quantity that expresses the amount of matter in a body. Walls and floors may be described in terms of the surface density (mass per unit area, kg/m2) of the wall face or the floor surface, which is the sum of the surface densities of each component of the construction. The density of materials is expressed as mass per unit volume, kg/m3, which can be provided via the core structure and linings such as in-situ concrete or solid dense block walls.

Mass per unit area (or surface density)

This is is expressed in terms of kilograms per square metre (kg/m2). This is often used to describe boards, panels, flooring and dry linings (see gypsum based board).


This can reduce structural vibration transmission and still maintain material performance and overall dimensions, examples include floating floor treatments such as resilient battens or cradles, or resilient ceiling bars.

Resilient ceiling bars

This acoustic solution is generally metal based and vary in thickness from 11 mm to 30 mm. They are mounted perpendicular to the joist span direction and can increase both airborne and impact sound insulation. Care should be taken to ensure that the ceiling board fixings into the resilient bar do not come into contact with the joists and reduce the potential performance.

Resilient noggin

This is a small section of resilient ceiling bar which is used to assist in bracing non load bearing partitions.


This is a single-number quantity (weighted) which characterises the airborne sound insulation of a building element from measurements undertaken in a laboratory, in accordance with BS EN ISO 717-1: 1997

Sound Insulation Testing

Sound Insulation Testing is required near the end of a development to show that the performance of the party wall and floor partitions meet the standards as stipulated in Building Regulations Approved Document E. The testing methods for airborne and impact sound insulation is in full accordance with the suggested methods presented in BS EN ISO 140-parts 4 & 7: 1998.


This is can improve low frequency sound insulation, for example in floors, by reducing the potential for deflection or movement of the primary structure, therefore the correct spacing and depth of joists is important.

If your project requires some acoustic design input and/or sound insulation testing please don’t hesitate to contact us at or call Darren direct on 07775623464 or visit our website at:

Acoustic Terminology F – L

Acoustic Terminology F – L 

Our previous blog explained the C-F of acoustic terminology, this blog further covers F – L.

Following on from our previous blogs which gave a brief description of

Flanking strip or edge strip

This is a resilient strip using foamed polyethylene normally 5 mm thick, which is located at the perimeter of a floor to isolate the floor boards from the walls and skirtings.

Flanking transmission

This is airborne or impact transmission between rooms that is transmitted via flanking elements and/or flanking elements in conjunction with the main separating elements. An example of a flanking element is the inner leaf of an external wall that connects to the separating ‘core’ of a wall or floor.

Flexible closer

This is a flexible cavity stop or cavity barrier which seals the air path in cavities linking adjoining dwellings.

Floating floor treatment (FFT)

This is a timber floating floor system which may use battens, cradles or platform base, all of which use a resilient layer to provide isolation from the base floor and adjacent wall elements.

Gypsum based plasterboard

This is a dry lining board applied to walls, ceilings and within floating floor treatments which has gypsum content. It may also have fibre reinforcement within the board.

Impact sound

This is sound which is propagated from a noise source through a direct

medium. An example of this is footfall on a floor.

Impact sound transmission

This is sound which is spread from an impact noise source in direct contact with a building element.


This is a strategy to limit the number and type of rigid connections between elements of construction.


This is the weighted standardized impact sound pressure level. A single-number quantity (weighted) to characterise the impact sound insulation of floors, in accordance with BS EN ISO 717-2: 1997.

If you have a project that requires our acoustic design service and/or sound insulation testing please contact us at or youhone Darren Direct on 07775623464. You can also visit our website at:



If you have a room that’s protected by a gaseous fire suppressant system, it is required to have an annual Room Integrity Test. Protected enclosures such as Server Rooms, Plant Rooms, and Laboratory’s all need to be tested on an annual basis, given the potential consequences of fire damage and the subsequent down time for critical assets.

Under BS ISO 15004, it states that an integrity test be undertaken prior to the handover of the enclosure and annually thereafter. Also, if the enclosure envelope has received new works i.e. new penetrations for electrical installations another room integrity test should be undertaken immediately after the works have been completed.

To allow a fire suppression system to work properly the room must have sufficient airtight to retain an extinguishing concentration for a specified period after discharge – usually 10 minutes. Failure to do so may cause the fire to reignite causing further damage.

Fire Damage to a Server Room.


We undertake room integrity testing to all types and sizes of enclosures, from large data centre’s which have a floor areas of hundreds of square metres to small server rooms not much bigger than a WC. In each case we carry out the necessary calculations prior to the test, and use high powered UKAS calibrated fan systems with integrity testing software to determine results immediately upon completion of the room integrity test.

Our experienced engineers continually ensure that the room integrity testing is clean and non-disruptive, using the latest door mounted fan systems to measure the air leakage flow. Throughout the test the room can carry on working as normal, with no requirement for shutdowns to your critical assets.

If you have a protected enclosure that requires a room integrity test or you think you have a problem in terms of your enclosure construction, please contact us at: or call Darren direct on 07775623464.

Designing Enclosures for Room Integrity Testing

Designing Enclosures for Room Integrity Testing 

When designing server/data enclosures, it is the responsibility of the user and system suppliers to ensure that the enclosure and extinguishing system meet the design requirements as stated in ISO 15004.


At the contract stage of the project, it is essential that responsibility for each of the enclosure requirements is made clear to all the relevant parties. In all cases it is important to consider the construction of the walls, floor and ceiling envelope when designing the enclosure containing one of your most important company asset(s) to be protected by the extinguishing system.  When designing the envelope for a protected enclosure there are  four critical factors to consider:

  1. Enclosure strength – to withstand pressure during gaseous suppressant discharge.
  2. Enclosure fire resistance – to withstand fire external to the enclosure.
  3. Enclosure pressure relief balance – to constrain the pressure differential across the enclosure structure to an acceptable level, by venting off excess enclosure gases during gaseous suppressant discharge.
  4. Enclosure air tightness – to aid retention of the agent after agent discharge.

In all cases the strength of an enclosure will be dependent on the materials of construction, the strength of fixings and attachments and the area they present to the load applied by the pressurised agent.

It is worth noting that Its been shown that once a fire – which has commenced externally to the protected area) breaks into the protected enclosure the agent will have little or no impact on asset protection. It is important therefore to maintain strict a‑minimum fire resisting enclosure of 60 min.


At APT we provide room integrity testing for a wide variety of types and manufacturers of fire suppression systems, whether it is part of a system installation or annual inspection or intermediate post work testing

For further information on our room integrity testing services, please contact our technical manager Darren on 07775623464; or email us at

Designing for Sound Insulation

Designing for Sound Insulation

Many of the dwellings in throughout the UK consist of large houses or office blocks that have been converted into flats. Unfortunately during the design stage of the project designing for sound insulation is not always shown the highest priority, so many converted dwellings fail their precompletion testing.


We have helped many of our clients achieve compliance with Part E, by undertaking some simple steps. We can undertake an initial sample sound test of the existing wall and floor construction to ascertain the existing sound insulation levels. Once we have established the sound levels for the existing construction, we can then look at extent of the acoustic upgrades to attain Part E Compliance. This is much more effective than just forwarding an acoustic design that may be to excessive and expensive, especially if the existing floor and/or wall only needs to improve by a minimal amount such as 1-3dB. By having the existing sound levels of the partitions we can recommend targeted, acoustic upgrades to comply with Building Regulations Part E.

Even though the sound insulation levels required to pass Part E for refurbishment projects are less stringent than new build projects – instead of 45dB for airborne its 43dB (2dB less), and for instead of 62dB for Impact Sound Testing its 64dB on new build (2dB more) it is still essential that the acoustic design is shown the highest priory from the start of the project.


In our experience, refurbishment projects usually achieve 30-35dB for airborne sound and 70dB for Impact Sound during the sample sound test – if the existing construction has not been acoustically upgraded. These figures do not meet the required 43dB & 64dB as stipulated in Part E of Building Regulations. As sound double every 10dB this is a massive failure and major acoustic improvements must be made.

On all new or converted developments, is it essential that good acoustic design is addressed right from the start of the refurbishment project, so the building passes the sound testing at the first attempt and prevents delays in handover.

If you would like advice on your acoustic design or require sound testing in London, please contact us now on 07775623464 or contact us at

Why do my Floors Squeak?

Why do my Floors Squeak?

We often receive complaints from clients in regards to their floors creaking. This is often because the Joists are often spaced too far apart, which can result in a reduction in floor stiffness. Over-notching of joists can also lead to a reduction in floor stiffness and also potential squeaking. Although the floors may pass the airborne and impact sound testing, however it won’t stop the squeaking of the floors under the extra load imposed by people walking above.


Other problems may be down to the contractor using 12mm floor boarding instead of 18mm to the top of the joists, again this may allow the boards to move and squeak. It may also be down to the chipboard not sitting level across the joists, this may down to the  joists being installed at slightly the wrong level or a joist hanger may have been hit or come loose during the build. If the joist has been built into the wall the bearing could be unsatisfactory. it may be as simple as a missing joist, or cut edge unsupported or an over span on the joists.

  • Incorrect bridging of resilient layer by over-long screws/nails
  • Fixings connecting ceiling boards to resilient bars should not bridge to joists
  • Extra wide joist spacing that reduces floor stiffness
  • Platform floor resilient layers damaged by inserting pipes and services within the layers
  • Reduction in stiffness due to use of joist hangers
  • Ceiling boards not staggered
  • Over-notching of joists for services reduces floor stiffness
  • Incorrect omission of flanking strips at floor edge perimeters.

In most cases, due to the complexity of acoustical and noise problems along with an overwhelming variety of material designs and combinations due to varying constructions, it is impossible to cover all problems in a short article such as this; however in our experience if the acoustic design is taken into consideration from the offset of the project, then it usually results in compliance with Building Regulations Part E.

If you have a project that requires acoustic design advice and/or sound insulation testing, then please contact us at: or phone me (Darren) on 07775623464.

Good Acoustic Design for Sound Testing

Good Acoustic Design for Sound Testing

To attain the standards stipulated within Building Regulations Part E, careful consideration should be shown to your buildings acoustic design  from the start of the project; however this requires different construction techniques and acoustic design detailing for new and build and conversion projects. With new build properties you have a blank canvas in terms of the overall design whereas conversions usually require you to work with the existing construction which can be quite difficult if the existing construction is not acoustically robust.


To try and overcome the problems with attaining Part E for your conversion project, we now offer an acoustic design package, which contains the following elements:

  1. Sample Sound Testing – of the existing construction. This offers an accurate overview of the acoustic performance of the existing partitions; this enables us to offer a targeted acoustic design using the sound insulation performance of the existing construction.
  2. Acoustic Design Review – a full design review of the proposed developments party walls and floors taking into account the performance characteristics of the existing construction as well as the buildability and materiel cost of the acoustic upgrade.
  3. Site Survey Visits – to let us view the existing site construction. This allows us to check for potential problematic construction such as inclusion of lightweight blocks in the existing construction. It also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines.
  4. Final Precompletion Sound Testing  – in compliance with Building Regulations Part E to help achieve building control sign off.

We have undertaken hundreds of design reviews around London and the South East with our clients achieving  a 100% pass rate where the acoustic review has been followed. If you would like some more information in regards to our acoustic services and/or sound testing services please visit our website at, or contact us at: or call me (Darren) direct on 07775623464.


Noise Damping to Improve Sound Testing

Noise Damping to Improve Sound Testing 

Noise damping is the most efficient and effective ways to control vibration and noise radiation at the source. Damping materials lessen this noise by turning the vibration into a low-grade heat. By using viscoelastic materials, it changes the resonant frequency of a substrate. By combining vibration damping materials and sound absorbers a composite acoustic construction can be achieved, that can control both airborne and structure borne noise – the final element for good soundproofing.


It is worth noting that a  large number of manufacturers now produce a wide range of systems designed to improve sound insulation in homes and commercial buildings. In all instances, the effectiveness of these materials will vary depending on the situation in which they are installed. When choosing the acoustic product/s, detailed information on the likely sound insulation performance should be requested from the supplier. If you have an existing property you should check the existing construction of the dividing wall/floor partitions and work back from there. You are advised to give careful consideration to the data supplied by a manufacturer before using a proprietary product. it is also worth noting that the sound insulation value/s given for each product will be ‘best case’ as they have been tested in laboratory conditions and not on site – this is usually worse result by up to 3-5 dB) which may be the difference between a sound test pass or failure.


Also when undertaking remedial work to improve the sound insulation, the acoustic materials are often quite heavy which may result in considerable weight being added to the structure of a property. Thus it is essential to check that the ceiling or floor joists can carry the increased loads satisfactorily.

So in a nutshell if you allow for the following four main elements of sound insulation on your acoustic partition design; Decoupling, Absorption, Mass and Damping, your development should pass the sound insulation test at the first attempt.

If you would like more information in regards to acoustic design and sound insulation testing, please contact us now at or call Darren direct on 07775623464.