Laboratory extraction arms provide a practical method of capturing fumes, vapours and fine airborne contaminants close to where they are generated. They are commonly used at laboratory benches, electronics workstations, pharmaceutical facilities, dental laboratories and other areas where a large extraction hood may be unnecessary or impractical.
However, not every extraction arm is suitable for every application. The contaminant, working environment, corrosion risk and potential for electrostatic discharge should all be considered before selecting a system.
Why at-source extraction matters
Airborne contaminants are generally easier to control before they disperse into the surrounding room.
A laboratory extraction arm positioned close to the source creates a local airflow that draws contaminants away from the operator and into the extraction system. South Africa’s Regulations for Hazardous Chemical Agents recognise local extraction ventilation as an engineering control for reducing exposure to airborne hazardous substances.
The effectiveness of an extraction arm depends heavily on positioning. Moving the hood further away from the source significantly reduces its ability to capture contaminants, so an arm should be easy for the operator to reposition as the task changes.
General-purpose laboratory extraction arms
A general-purpose arm is suitable for many laboratory and light industrial applications where aggressive chemicals or electrostatic discharge do not present significant risks.
Typical applications can include:
- Soldering and light assembly
- Laboratory fumes and vapours
- Dental laboratory work
- Adhesive and solvent applications
- Fine dust generated at workstations
- Small-scale inspection and processing tasks
Flexible movement is important because the extraction point often needs to be positioned very close to the work without obstructing the operator.
For the FX2 range, different arm diameters allow airflow requirements to be matched to the application rather than using excessive air volume.
When is a chemical-resistant arm required?
Laboratory fumes are not always chemically neutral.
Acids, solvents and other corrosive substances can attack materials used in conventional extraction equipment. Where aggressive vapours are present, a chemical-resistant extraction arm should be considered.
The FX2 Chemical arm uses corrosion-resistant construction specifically intended for aggressive environments. This helps protect the extraction equipment while allowing fumes to be captured directly above or alongside the process.
However, chemical compatibility should always be evaluated against the actual substance being extracted. An extraction arm is only one part of the system; ducting, fan materials, filtration equipment and the final discharge arrangement must also be suitable.
What is an ESD extraction arm?
Electrostatic discharge, or ESD, is particularly important in electronics manufacturing and other environments containing sensitive components.
A small static discharge that is harmless to a person may damage electronic components or affect product reliability. ESD extraction arms therefore use conductive materials designed to reduce the risk of static electricity accumulating in the extraction equipment.
Typical applications include electronics assembly, soldering stations and work involving electrostatically sensitive devices.
An ESD-rated arm should not automatically be assumed to make an installation suitable for a hazardous explosive atmosphere. Where flammable gases, vapours or combustible dust may be present, the complete installation and area classification must be assessed separately.
Airflow and arm diameter matter
More airflow is not always better.
As an example, FX2 extraction arms are available in different diameters, with recommended airflow increasing according to arm size. A 50 mm arm may operate at approximately 50–110 m³/h, while larger 75 mm and 100 mm versions can accommodate higher airflow requirements.
Correct airflow should provide effective capture without creating unnecessary noise, energy consumption or disturbance to sensitive laboratory processes.
Selecting the correct laboratory extraction system
Successful laboratory fume extraction requires more than selecting an arm from a catalogue. The contaminant, required capture distance, airflow, chemical compatibility, workstation layout and final filtration or discharge method should be considered together.
Envirox specialises in industrial air filtration and at-source extraction systems. By evaluating the actual application before selecting equipment, Envirox helps South African laboratories and manufacturing facilities develop extraction systems that are practical, efficient and appropriate for the contaminants being controlled.
