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FAQ (Frequently Asked Questions)

1. What is your turn-around time for repair, service and calibration?

At OptiCal Sciences Ltd, we are extremely proud of our fast turn-around time.

We usually ask our customers to set aside 5-7 working days for a calibration or repair (depending on whether required parts are in stock for any repairs).

We also offer a service where our customers can request high priority for their calibration or repair and we can even sometimes offer same day calibrations (subject to conditions). Should you have any specific deadlines for the completion of work, please make sure to let us know and we will be pleased to accommodate you wherever possible.

In order to make the turn-around as quick as possible, please ask one of our staff members to provide you with a quotation in advance (if you have not received a reminder quotation already). If you have an account with us, submitting a purchase order along with your instrument will greatly speed up the process.

2. What instruments can you repair, service and calibrate?

Please refer to our list of instruments we can repair, service and calibrate. Should your instrument not appear on the list, please feel free to contact us and see if we are able to accommodate your instrument.

3. What is the process of sending our instrument to you for calibration, service and/or repair?

Please send any instrumentation to: OptiCal Sciences Limited, Envirotest House, Anglia Way, Moulton Park Industrial Estate, Northampton, NN3 6JA with a completed Equipment Return Form. For a faster turn-around time, please specify what work you require, or contact us with your requirements.

4. Do you offer service contracts?

Yes, we do offer contracts for the service and calibration of instrumentation. Please  contact us with your requirements and we will be able to generate a price to best suit your needs. 

5. Are we able to hire instruments from OptiCal Sciences Limited?

Yes, we offer the hire for a wide variety of instruments. Please  contact us with your requirements and we will be able to assist you.

6. What are the main differences between the new ISO 14644-1:2015 vs 1999 cleanroom classification standards?

The limit for 5 um particles is removed for ISO Class 5

ISO Class 5 no longer has a limit for 5um particles. The GMP 2008 reports continue to include the same limits for 5um particles as before, and the formulas are not changing for GMP 2008 reports at this time.

Elimination of 5um limits for Class 5 & Class 6 locations

The limits were removed for Class 5 and Class 6 locations because there were too few particles to be statistically significant. For general cleanroom applications, this was a valid decision. Nonetheless, elsewhere in the standard it recognizes that some applications may still need to monitor these sizes, and life science is an application with a special need to continue monitoring 5um particles.

The life science industries have focused on 0.5um and 5.0um because these sizes effectively bracket the range of viable, airborne particles. Viruses, for example, may only be 0.1um in size, but they are only airborne in clusters, not individually. The number of 5um particles in a Class 5 area is typically as few as 0 to 1 particle. A small increase in counts due to viable particles would be lost in the background counts for 0.5um particles, but should stand out as unusual in the 5um channel. So, monitoring 5um particles in critical, Class 5 areas is not about statistics, but about having an early warning of potential microbial colonization in the area; this allows production to be halted before thousands of dollars of raw materials are wasted, and until confirmation of a problem or lack of a problem, can be established by viable sampling.

For this reason, and because the EU GMP, Annex 1 has not indicated a relaxation of 5um requirements, life science companies should continue to monitor 5um particles in Class 5 areas, as in the past.

The minimum number of sampling locations is different

In the 1999 standard, the minimum number of locations was equal to the square root of the area in square meters. This has been replaced with a table and more locations will be required in most cases. A new formula can be used for areas greater than 1000 square meters.

This requirement applies to cleanroom certification; monitoring does not specify the number of locations to monitor. ISO 14644-2 provides guidance for monitoring, but the Class limits are established in ISO 14644-1, and so it remains an important standard for monitoring, as well.

Removal of the 95% UCL requirement

For 10 locations or more, ISO 14644-1 has only required a straight average. For fewer than 1- locations, the standard has required a statistical calculation (95% UCL) that assures with 95% of the areas in the room will not exceed the calculated value, which needs to be less than the room limit to pass.

The problem with the calculation is that it is strongly influenced by the standard deviation. The wider the disparity in the counts between areas in the calculation, the greater the standard deviation and the greater the calculated 95% UCL number will be. This number may be higher than the room limit, even though none of the (up to 9) samples taken are even close to the limit. To avoid this, the standard allowed one outlier to be excluded from the calculations. However, even with this exclusion, there were situations where there were areas in a room that were clean, and others that were very clean, and even with one exclusion, a false failure may be reported due to the high standard deviation. The standard now avoids the problem altogether by requiring that all individual locations pass and that no 95% UCL is calculated.

The new standard is essentially a relaxation of requirements. Areas that passed before would still pass, but for certification (rather than monitoring), more time may be required due to the increased number of locations required in most instances. In terms of monitoring, the removal of the UCL calculations can eliminate some deviations. For the 5um channel, in theory it may also eliminate deviations due to 5um counts, but in practice, the limit was 29 particles per cubic meter, so, in practice, probably very few deviations will be avoided. For more information, please contact a member of staff.

7. Can particle counters detect water vapour?

Yes. A particle counter will detect anything that scatters light and has a refractive index different from the surrounding air. Even water vapor will be detected, whether it is condensation that forms when cold air from a cold storage room escapes into warmer air outside, or whether it is unevaporated droplets from steam or from sterilizing sprays.


ISO 9001:2008 Certification

We are currently certificated to the requirements of ISO 9001:2008 by Intertek Group PLC, who are accredited by the United Kingdom Accreditation Service (UKAS). UKAS, as an accreditation body, work with other similar bodies around the world to ensure that the standard of auditing is uniform and adequate. Some certification bodies do not have this accreditation and therefore the standard of their auditing has not been independently verified. For further details please see the web page linked here: http://www.ukas.com/about-accreditation/default.asp

Please click here to view a copy of our ISO 9001:2008 Certificate