By workplace & process
Melting plastic gives off a fume whose make-up shifts with the polymer, the additives and the temperature - and spikes when a machine overheats or purges. What the extraction test has to confirm.
The short answer
Injection moulding and extrusion heat plastic until it flows, and that heat gives off a fume. What is in that fume depends on the polymer, the additives and how hot the material gets - and it rises sharply when a machine overheats, sticks or is purged. There is no single limit for the mixture, so control is a matter of holding the process and capturing the fume, and the test has to catch the peak, not just the steady state.
The detail
Different plastics degrade differently. ABS, polypropylene, polyethylene, PVC, polycarbonate, nylon and PBT each release their own mix of volatile organic compounds, and additives and colourants add more; styrene, formaldehyde and stearate fumes can all appear. Because it is a variable mixture, there is no single workplace exposure limit, so exposure has to be controlled as low as reasonably practicable, guided by HSE advice on controlling fume during plastics processing.
The health effects are real. Occupational asthma has been documented from heated polypropylene and from polyethylene - the latter sometimes called meat-wrapper's or paper-wrapper's asthma - and the fume irritates the eyes, nose and throat and can reduce lung function. Crucially, emissions rise steeply with temperature and residence time, so the worst exposures often come not from normal running but from overheating, degraded material and purging. Different lines can also demand very different capture - a small precision moulder and a large extruder running hot are not the same job - so control that suits one machine cannot be assumed to suit the next.
What it means for you
A thorough examination and test of plastics-processing LEV confirms that capture at the nozzle, the mould area and the purge point is holding the fume and moving air at the commissioned rate. Because the biggest emissions come at the peaks, good extraction and a good test have to account for those moments rather than only the calm of steady production, and the examiner checks performance against the design at least every fourteen months with user checks between.
Holding process temperature and dwell time is itself part of control, since it limits how much fume is generated in the first place. But where fume is produced, proving the LEV still captures it - especially at purge - rather than assuming a hood fitted years ago is coping, is what keeps a moulding shop's air under control.
The service behind the guide
We test plastics-processing LEV at the nozzle, mould and purge against the thermal fume it has to control - including the peaks - with a clear report and next test date.
Questions
It depends on the polymer, the additives and how hot the plastic gets. ABS, polypropylene, polyethylene, PVC, polycarbonate and nylon each give off different mixes - volatile organics, styrene, formaldehyde and stearates among them.
There is no single limit for the mixture, so exposure must be controlled as low as reasonably practicable. HSE guidance covers controlling fume during plastics processing, including holding process temperature and dwell time.
Yes. Occupational asthma has been documented from heated polypropylene and from polyethylene, sometimes called meat-wrapper's or paper-wrapper's asthma. The fume also irritates the eyes, nose and throat.
Fume rises steeply when plastic overheats, sticks or is purged, so the biggest exposures are often at those peak moments rather than during steady running. Good extraction and a good test have to account for the peak.
At least every fourteen months under COSHH, with user checks between. The test confirms capture at the nozzle, mould and purge point is still performing to the design.
Phoenix Duct Clean · by the numbers
We test plastics-processing LEV at the nozzle, mould and purge against the thermal fume it has to control - including the peaks - with a clear report and next test date.