Can I keep an extraction unit at the laboratory without installing an expulsion chimney?


This morning we received a request from one of our customers, a very common question:

“I am the owner of a small business and would like to use your extraction unit in combination with a machine in my lab to suck chips and dust. Can I nevertheless use it inside the department without arranging for release into the atmosphere?

Since they are encased, is it possible to add an additional filter in order to avoid release into the atmosphere?”

Basically, the customer is asking if a filtering unit can be kept inside the laboratory without installing an expulsion chimney, perhaps by adding an additional filter…

The question is very interesting and common at that… I wonder how many times you have asked yourself the same thing?

But what do Italian regulations say with regards to this?

Products Personal Advice

A bit of confusion

Surely in this specific field there is a lack of coordination between public Agencies, thus leaving room for subjective and often arbitrary interpretations. This leaves the sector operators with a feeling of uncertainty regarding the methods and procedures to follow in order to comply with legislative provisions.

In principle, experts in the area of industrial hygiene and safety do not recommend (and in fact prohibit its application) resorting to dust abatement systems with recirculation of the treated air into the workplace. In particular, in view of pollutants having carcinogenic or mutagenic properties.

Timber and wood chips background

Timber and wood chips background

In the wood sector…

For example, in case of wood processing activities, the presence of extraction systems located inside the workplace, with no expulsion of the extracted air to the outside, does not comply with proper prevention criteria. This following the acknowledgement that hardwood dust is carcinogenic.

Hence, we can state that it is usually not advisable to resort to dust abatement systems with recirculation of the treated air back in the workplace.


However, there are some exceptions. In fact, regional regulations acknowledge that, in certain work situations, such as, for example, small businesses located in downtown areas, it is difficult to release the extracted air outside.

This exception is therefore allowed for small business with relatively limited work volumes, provided they comply with a series of very strick parameters, including:

  • the installation of an effective additional filtration system, so that the outlet air has a very high degree of purity
  • the installation of a series of monitoring and safety instruments on the filtering unit
  • thorough routine and extraordinary maintenance, recorded in the special maintenance log.

In conclusion

It is usually not acceptable to resort to dust abatement systems with recirculation of the treated air back in the workplace. The situations where this is acceptable are few and entirely particular.

Do you have additional questions or need assistance? Contact us

Products Personal Advice