In a hospital, a sewage smell is not only a comfort issue — it is a visible sign that the water barrier in the trap has gone. And through that same open path can travel bioaerosols from the drainage system, a well-documented reservoir of hospital pathogens. That is why drains in healthcare must not depend on manual maintenance.
Where the trap fails in a hospital
Floor drains, sinks and showers all have a trap — water that holds gases and aerosols from the sewer down. The barrier disappears when the water evaporates, or when negative pressure breaks it:
- Rarely used rooms — empty wards, isolation rooms, ancillary and plant rooms; the water in the trap evaporates within weeks.
- Seasonally or periodically closed sections — the traps dry out and greet the first staff member back with an odour.
- Negative pressure in the pipework — a sudden discharge of water elsewhere can pull water out of the trap and break the barrier.
Drains and traps are documented reservoirs of Pseudomonas aeruginosa and of multi-resistant organisms (CRE, MRSA). A dry trap = an open path for bioaerosols out of that reservoir.
Why a manual protocol is not enough
The standard solution — a schedule for manually flushing traps with water — depends on the human factor and tends to fail in exactly those rooms that are rarely used, which are precisely the highest-risk ones. The water goes in, then evaporates again; protection is temporary and uneven. In an environment where infection control is critical, the barrier must not depend on whether someone got round to doing the rounds.
A passive seal as a permanent barrier
The Green Drain™ silicone seal has a one-way valve: it lets water pass downwards while it is flowing, and the moment the water stops it closes and mechanically blocks gases and bioaerosols, even when the trap is completely dry. For a healthcare environment that means:
- A permanent barrier that does not depend on water, chemicals or a manual schedule
- Medical-grade silicone that does not degrade; no power supply and no moving parts to fail
- Installation into the existing drain with no tools, ~30 s, room by room without closing a ward
- >99.9% blocking of viral aerosols (SGS) — relevant for infection control
We cover the link between drains and hospital infections in more detail in a separate article — see the link below.