How often are medical vacuum bacterial filters changed?

How often

• Follow the manufacturer's recommendations for replacing the bacteria filter elements, so that the vacuum pump oil is not contaminated; this is usually annually or after a specified number of hours, whichever comes soonest (HTM 02-01 Part B, note to the central vacuum plant tasks).
• Filters on medical gas pipeline systems should be changed at the intervals recommended by the manufacturer, and more frequently if the filter becomes wet or the pressure drop across it exceeds the supplier's specification (11.123).
• Every week, check the bacteria filter and pump exhaust drainage flasks for liquid, and inform the Authorised Person (MGPS) if liquid is present (weekly tasks for vacuum plant).
• If water or other liquids are found in a bacteria filter drain flask, it should not be opened without first consulting the Authorised Person (MGPS) and the infection prevention and control (IPC) team (11.181).
• After a fluid contamination incident in the pipeline, both decontamination procedures include, once the system is back in use, checking the plant filters for evidence of fluid and changing the bacteria filters where it is present (vacuum system decontamination procedures).

How the change is done safely (HTM 02-01 Part B, 11.191 to 11.202)

1. Before the work, ask the user about any toxic or infectious materials that may have entered the system; if occupational exposure limits for toxic substances may be exceeded, advise the safety officer and use an appropriate air-fed respirator.
2. Work under the permit to work: the MGPS permit may be used for general work on vacuum systems, and Appendix D adds a second permit for changing bacteria filters, which allows the IPC team and the health and safety officer to intervene where additional infectious or toxic hazards have been identified.
3. Provide two heavy-duty polythene bags, and wear a disposable mask, a disposable apron, disposable gloves of strong latex or another non-allergenic material and safety goggles, plus disposable overshoes if the hospital requires them.
4. Place the used filter directly into one bag and seal it; put that bag, with the gloves, mask and overalls, inside the second bag, seal it and label it as clinical waste to be incinerated.
5. Notify the waste disposal department or the Authorised Person (MGPS) so that the bags are collected and disposed of.

Appendix D of Part B gives a sample standard operating procedure and a filter change procedure suitable for posting on or near the vacuum plant (11.202). In Part A, each bacteria filter should be marked biohazard, with a description of a safe procedure for changing and disposing of the filters and emptying the drainage trap (10.24), and each of the duplex subassemblies should be rated for the full plant capacity, with manual isolating valves so that either can be used independently (10.23). Waste oil and condensate from the pumps and exhaust traps should be disposed of as hazardous waste (11.190): because the bacteria filters protect the pumps, Part B classes them as hazardous, not clinical, waste.

ULTRAVAC

The ULTRAVAC basic configuration includes 2 bacterial filters with liquid separator. The high-efficiency filters have vacuum differential gauges and isolating valves, and a transparent liquid separator or drain flask collects liquids and impurities to protect the bacterial filter element. The datasheet lists bacterial filter elements, with oil and oil separators, as the parts replaced in maintenance.