What’s a thorough examination and test?

Companies that have installed local exhaust ventilation systems have to undertake a “thorough examination and test” (TExT) at least once every 14 months. The objective of the TExT is to find any significant defects and to have them remedied to regain control. In most cases they will employ an external organisation to carry out these

Update on BOHS Module P601

Report Requirements Candidates taking the BOHS proficiency module P601(Commissioning and Thorough Examination and Testing of Local Exhaust Ventilation Systems) who successfully pass the written exam, case studies and practical test during the course  are required to submit two test reports to BOHS within 6 months of the course (there are a lot of hoops to

To test or not to test?

I recently received the following query from a client: “I have come across various items of equipment which appear to have integral LEV types of arrangement ……..  All have been introduced to reduce the level of dust or chemical that may have a deleterious effect on the user of the equipment.  I am unsure if

Testing walk-in spray booths

We recently received a query from a client who carry out paint spraying of isocyanate based two pack paints in a large walk-in type spray booth. They wanted us to carry out sampling to help them to decide when it was safe to enter the booth without their workers wearing their air fed masks. This

What is “static pressure”?

We were running the BOHS module course P601 “Commissioning and Thorough Examination and Testing of Local Exhaust Ventilation Systems” last week. One of the concepts delegates often find difficult to get to grips with is “static pressure”, which is one of the main engineering measurements carried out during the testing of a local exhaust ventilation

Visualising Airflow

It can be difficult to make a qualitative evaluation of the effectiveness of LEV hoods because the contaminants are either invisible (in the case of most gases and vapours) or difficult to see (with fine dusts). Two main techniques can be used to overcome this problem: smoke tests dust lamps Smoke released in the vicinity

Testing LEV systems when baseline data isn’t available

One of the main problems we encounter when carrying out a thorough examination and test of a local exhaust ventilation (LEV) system is the lack of “baseline data” – i.e. information on what the pressures and velocities should be when the system is operating in accordance with the design specification. Providing the system has been