Local Exhaust Ventilation (LEV)

Visible escape, damaged ductwork, blocked filters and complaints about extraction need investigation. The absence of visible dust does not establish adequate control of exposure. Start with the substance and task, then assess how the system captures and removes the contaminant during representative work.

The scope can include assessing the process and existing extraction, developing a design brief, coordinating installation, improving hoods or ductwork, maintaining components and arranging commissioning. The work identifies the hood, duct, filter or collector, fan and discharge arrangement as parts of one system.

Outputs include the defined process and capture requirement, equipment information, commissioning results and instructions for use and maintenance. HSE's LEV guidance explains the relationship between design, commissioning and subsequent examination. A fan replacement alone does not establish that the whole system controls exposure.

LEV differs from general room ventilation: it captures contaminants near their release point before they spread into the workplace. Hood position, the way the task is performed and competing air movement affect that capture. Operators need a method they can use consistently during normal work.

Changes at one branch can affect the rest of a shared system. Assess simultaneous use, duct condition and the fan's operating arrangement before adding another extraction point. A stronger fan is not automatically the right answer to poor capture or a badly positioned hood.

Provide the process description, substances and safety data, exposure assessment, existing drawings and commissioning information. Include recent examination reports, maintenance history and details of alterations. State which workstations operate together and how the job changes through a production cycle.

Arrange observation of representative work with the production and safety teams. Identify access restrictions, cleaning methods and waste handling. Where flammable substances or combustible dusts are involved, the specialist assessment must address those hazards and associated equipment requirements within the design brief.

We establish the process and control objective, review the existing system and agree the specialist assessment or works package. Findings distinguish a maintenance defect from a design or work-method problem, so the proposed action addresses the cause.

Installation and alteration are coordinated with production and other services. Commissioning establishes the intended performance and usable reference information for future checks. Handover includes operating instructions, maintenance tasks and outstanding actions, with the relevant staff shown how the extraction must be positioned and used.

The contaminant, number of capture points, duct routes, filtration, discharge location and access affect cost. A local repair differs from changing a shared system or providing new plant. Additional process or exposure assessment can be necessary to establish the correct scope before equipment selection.

Plan how the affected work will be controlled while extraction is unavailable. An installation window must include commissioning and user handover, not only fitting the equipment. State the responsibilities for electrical supplies, building penetrations, waste removal and reinstatement when comparing proposals.

Industrial and manufacturing sites need extraction matched to the material and process. Education needs workshop use and supervision reflected in the operating instructions. Healthcare and care needs the particular task and specialist control requirements defined before equipment is chosen.

These examples sit within the full sector range. Our service and project offering supports the sectors we serve, with specialist requirements established for each workplace rather than assumed from its industry alone.