Hosokawa Micron Ltd are now able to offer HEPA Filter Integrity Tests either as a specific task or as part of a planned maintenance programme.
Industry recommends that HEPA filters be checked at 14 month intervals or less or immediately after filter change. This is because where high efficiency filters are fitted, it is important that the filter housing/sealing device does not allow particulate material to pass and therefore compromise the classification of the controlled environment installation that is being served.
The Filter Integrity Test is commonly referred to as a DOP test because the original smoke used in the test was generated using Di-Octyl Phthalate. This chemical was found to have carcinogenic properties and was subsequently substituted by a mineral oil, Shell Ondina EL. The smoke generated from this has identical characteristics and the term DOP testing remains, although it is now understood to mean