Effective odour abatement in sensitive locations by Passive Filters

OSIL are a leading provider of activated carbon-based, passive filters or odour control units (OCUs), which are commonly utilised to adsorb vent gases from sewerage processes.

These high-quality ‘passives’ offer effective odour control and hydrogen sulphide removal, and are suitable for use with activated carbon in granular or pellet form.

Passive Filters

The ‘passives’ offered by OSIL come with a disposable/refillable filter and can be mounted at the top of the pipe or at waist height.

Systems can be disguised as trees, bollards and lamp posts where odour control is required in sensitive areas.


Range of construction materials and bespoke design service to suit your environment.

Disposable or fillable filters and powered vent option available.

Typical applications of Passive Filters

  • Sludge holding tanks
  • Sewage holding tanks
  • Fume cupboard exhausts
  • Waste holding tanks
  • VOC removal for oil storage tanks
  • Pump sumps under positive pressure

Technical specification

300 sq passive

Uses a single 300mm square cartridge

Used on tank covers where weight bearing may be a design factor

600 sq passive

Uses either a single or double cartridge arrangement depending on the potential airflow

Used primarily on wet wells and covered channels

Tube Vent Unit

Uses a cartridge in a tube of up to a maximum of 300mm diameter

Can be designed to blend in with surrounding architecture

A low cost, fast turnaround activated carbon resupply service is available to support this solution.