By workplace & process
Few print rooms picture themselves as an LEV site, but solvent vapour from fount solutions and wash-up is the invisible exposure. Where the VOCs come from, and what a test of the extraction has to confirm.
The short answer
Most print rooms think about ink, paper and machinery, not extraction. Yet the real exposure is solvent vapour - isopropanol from the fount or damping solution and hydrocarbon solvents from wash-up and blanket cleaning - drifting through the room across the shift. Because it is largely invisible, the LEV duty gets overlooked, and where extraction exists it is often never tested.
The detail
In offset and litho printing the biggest single contributor is usually isopropanol added to the fount solution, backed up by hydrocarbon wash-up and blanket-cleaning solvents. Isopropanol has a workplace exposure limit of 400 parts per million as an eight-hour average with a 500 parts per million short-term limit. Studies of print rooms have found that automatic cleaning cycles tend to raise solvent exposure while separate exhaust ventilation lowers it - a direct pointer to where control belongs.
Flexographic, gravure and screen printing lean more on solvent-based inks and screen-wash, adding compounds such as toluene, esters and ketones. Occupational exposures in printing processes are classed by IARC as possibly carcinogenic, largely reflecting older exposures to substances now much reduced. For most print rooms today the everyday concern is the effect of solvent vapour: headaches, drowsiness, poor concentration and irritation of the eyes, nose and throat, along with dermatitis from skin contact. Substituting lower-solvent or vegetable-based inks and moving to enclosed cleaning systems can cut the vapour at source, and where those steps are taken the load on the extraction eases - but most rooms still lean on local exhaust ventilation as the practical day-to-day control, which is exactly why its condition matters.
What it means for you
A thorough examination and test of print-room LEV confirms that capture at the press, the wash-up stations and any drying is holding the vapour, moving air at the commissioned rate, and not simply venting into the same room. Solvent vapour is denser than air and spreads low, so hood position and airflow matter, and the examiner checks them at least every fourteen months with user checks between.
The recurring problem is a small print room that never recognised it had an LEV duty at all, or a system installed years ago and never re-tested while workloads and cleaning methods changed. Proving the extraction still controls the vapour - rather than trusting that the doors and a bit of general ventilation are enough - is what keeps a print room's air safe to breathe.
The service behind the guide
We test print-room LEV at the press, wash-up stations and drying against the solvent vapour it has to control, with a clear report and next test date.
Questions
Mostly from isopropanol in fount or damping solutions and from hydrocarbon wash-up and blanket-wash solvents. Flexo, gravure and screen printing add solvent-based inks and screen-wash. It is largely vapour, so it is easy to miss.
Isopropanol has a workplace exposure limit of 400 parts per million as an eight-hour average, with a 500 parts per million short-term limit. Studies show automatic cleaning raises exposure and separate exhaust ventilation lowers it.
Occupational exposures in printing processes are classed by IARC as possibly carcinogenic, largely from historic exposures now much reduced. The day-to-day concern for most print rooms is solvent vapour causing headaches, drowsiness and irritation.
If solvent use generates vapour that people breathe, exposure has to be controlled - and local exhaust ventilation is often the practical control. Small rooms are exactly where the duty gets overlooked.
At least every fourteen months under COSHH, with user checks between tests. The examination confirms capture at the press and wash-up is holding to the commissioned performance.
Phoenix Duct Clean · by the numbers
We test print-room LEV at the press, wash-up stations and drying against the solvent vapour it has to control, with a clear report and next test date.