UV measurement in medical applications and GMP settings
In medical UV applications the dose determines both effect and risk – which is why irradiance and dose are monitored by measurement there rather than controlled by a set time. Three tasks have to be distinguished: the ongoing checking of therapy devices, the monitoring of disinfection in clinics and laboratories, and the testing of devices for photobiological safety. Measurements are taken with spectrally or broadband calibrated radiometers.
Which quantity for which task
Releasing a therapy device depends on the irradiance in the treatment plane; the treatment itself depends on the dose integrated from it. The definitions and units of both quantities are set out in the overview of radiometric quantities. The sensor has to match the spectral range of the source – UVA, UVB or UVC – because a sensor with broadband weighting deviates systematically on a narrowband source; the cause is described in the article on spectral mismatch. How often recalibration is due is covered under calibration interval for UV measuring devices.
The procedures themselves – action spectra, dose quantities and measurement in the treatment plane, from narrowband UVB therapy to photodynamic therapy – are covered on the market page medicine and phototherapy.
Special requirements for UV measurements in a GMP environment
The GMP environment (Good Manufacturing Practice) is crucial for quality assurance in production, particularly in the pharmaceutical, biotechnology and food industries. GMP standards ensure that products are consistently produced and controlled according to quality standards.
Here is a summary of the specific requirements in the GMP environment, with a focus on user protection / passwords and data recording:
Quality assurance systems GMP requires the implementation of comprehensive quality assurance systems. These systems must monitor all aspects of production processes and environments to ensure compliance with quality standards. This includes regular staff training, adherence to strict procedures and ensuring equipment integrity, which includes UV calibration.
Validation and qualification
All equipment, systems and processes must be validated and qualified to prove their suitability and consistency for the intended purpose. Documentation of these validations is a key part of GMP requirements and must be accurately maintained. Existing processes are rarely changed, and as your supplier of UV measuring devices and light sources, we adhere to this.
User protection and passwords
Access controls Strict access controls are required in the GMP environment to ensure that only authorized personnel can access sensitive areas and systems. The use of passwords and other security mechanisms helps to protect the integrity of the production environment. Our products support different user groups, locking of settings and automatic data logging of UV measurement data.
Data recording
Documentation and records GMP requires complete documentation of all production processes. Data must be tamper-proof and stored in such a way that it can be traced and verified. The electronic data recording of UV measurement data includes device identification, calibration date etc. for this purpose.
In summary, compliance with these special requirements in the GMP environment is not only a question of legal compliance, but also crucial for ensuring product quality and safety. Just ask us!
The medical procedures themselves – action spectra, dose quantities and measurement in the treatment plane – are covered on the market page medicine and phototherapy.
Frequently asked questions on UV measurement in GMP settings
What does a GMP setting require of a UV measuring device?
Above all access control and traceable recording. In a GMP setting only authorised personnel may access sensitive systems, which is why passwords and separate user groups are required. In practice this means, for a UV measuring device: several user groups, locked settings so that an approved measurement setup cannot be changed unnoticed, and automatic recording of the readings instead of handwritten logs.
What must the data record of a UV measurement contain?
GMP requires complete documentation. The data must be stored tamper-proof and kept in a way that keeps it traceable and verifiable. A UV reading therefore needs at least the device identification and the calibration date – without both, a reading does not hold up in an audit, because it can no longer be established which device in which calibration state produced it.
What do validation and qualification mean for a UV measuring device?
All devices, systems and processes have to be validated and qualified, that is, to demonstrate their suitability and consistency for the intended purpose. Documenting that evidence is itself part of the GMP requirements and has to be kept accurately. For metrology this means: it is not the device alone that is qualified, but the measurement setup including sensor position, distance and calibration chain. The methodical approach is described in the proof of capability of UV measuring systems.
Why does device continuity matter in a GMP setting?
Because validated processes are rarely changed. A successor device with different sensors or a different spectral range means, if in doubt, a fresh validation – with all the documentation that entails. What matters is therefore the long-term availability of sensors and spare parts, the option to recalibrate the same device, and an unchanged measurement setup over years.
Author: Dr. Mark Paravia
Dr.-Ing. Mark Paravia is the managing director of Opsytec Dr. Gröbel GmbH in Ettlingen and heads the accredited calibration laboratory. Following his research on pulsed xenon excimer discharges at the Institute of Lighting Technology at KIT, his current focus is on optical radiation measurement technology. He is a recognized UV expert, vice-chair of the DIN Standards Committee FNL 7 “Optical Radiation,” and a member of the DVGW Project Group on UV Disinfection.
