Reliability of HEPA filter
Air handling represented a unique challenge to the BioTechnique facility, since all of the products that BioTechnique produces must be manufactured in an aseptic environment. If a HEPA filter was somehow compromised and did not provide at least a 99.97% reduction in non-viable particulates, it could cause potential microbial growth in a product required to be sterile. Risk assessment analysis showed a potentially critical impact to patients if non-sterile products were used, which was unacceptable.
A HEPA breach can be detected during the prescribed AQL sterility sampling of the product, during required environmental monitoring, or during the biannual HEPA certification process. However, a more substantial engineering solution was needed to ensure that the products manufactured by BioTechnique maintained the highest possible quality standards. After the product is formulated, filled, inspected, labelled, packaged, tested and released, there is no more opportunity to detect a quality issue. BioTechnique management therefore mandated, after assessing the potential impact to patient safety, that the Engineering Department seek a solution to improve the reliability of the manufacturing process and the quality of the product, while at the same time reducing the facility’s energy consumption.
In late 2014, the company embarked on a Lean Six Sigma project to improve the reliability of its manufacturing facility and reduce the energy costs of maintaining the Grade A (ISO 5), Grade B (ISO 6), Grade C (ISO 7) and Grade D (ISO 8) areas. National and local energy incentives, such as the State of California Title 24 programme, have encouraged many pharmaceutical firms like BioTechnique to initiate energy conservation projects.
Challenges 1 – Failure of existing HEPA filters
Challenges 2 – Reduce the energy consumption of HEPA filters
Challenges 3 – Improve the reliability of HEPA filters
BioTechnique undertook an engineering study to determine the return on investment by purchasing the new PAO compliant ePTFE filter media, compared to traditional glass media. The study was designed to determine the optimal filter pack depth of the ePTFE filter media to install, relative to the legacy microglass filter media.
To ensure no statistical bias, BioTechnique constructed a test rig that would allow testing in a controlled environment, ensuring that the testing methodology was statistically sound and reproducible, and would produce meaningful data to draw a defendable conclusion. The study was composed of tests that were conducted three times, each time using three filters of each type, including two traditional microglass HEPAs and the 50mm and 75mm ePTFE HEPA filters. This study therefore utilised 36 different tests, resulting in a statistically meaningful study.
This graph represents the data collected in February 2015 for the four filter types. The ePTFE 50mm had approximately 30% less pressure drop than the 100mm microglass HEPA. The ePTFE 75mm had a 36% less pressure drop than the 100mm traditional microglass HEPA.
BioTechnique calculated the total projected annual energy savings due to the lower pressure drop ePTFE HEPA filters to be 9,350 kWh.
These tests demonstrated that HEPA filters constructed of ePTFE media are significantly stronger and more reliable than traditional microglass media.
- AAF’s MEGAcel II filters outperform the competition with a 100% leak-free certification.
- ePTFE filters reduced filter failure and environmental monitoring excursions, resulting in lower production loss and labour costs.
- Utilising ePTFE filters increased BioTechniques time between recertifications, increasing cleanroom uptime.
- The lighter weight of the MEGAcel II filters allowed for a quicker installation—a labour savings advantage.
- ePTFE media has a dramatically lower pressure drop than traditional microglass media, resulting in significant energy savings for Grade A and Grade B cleanrooms.
Recommended Product & Solution
Within the pharmaceutical industry, strict requirements on air purity levels are necessary because of the direct effect that airborne contamination has on the quality of the pharmaceutical products. Anything that could come into direct contact with a pharmaceutical product is a potential risk toward contamination.
Energy efficient mini-pleat filter with a sturdy aluminum frame, boron-free media pack and outgassing-free separator. Final filtration for sensitive microelectronic cleanrooms and laminar airflow systems.