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

Controlling solder fume

In a previous post I discussed the health risks associated with exposure to the fume generated during soldering with rosin cored solder. It’s a respiratory sensitiser, and is one of the main causes of occupational asthma in Great Britain. The fume is generated due to thermal degradation of the flux – usually containing colophony (also

Designing and managing local exhaust ventilation

Local exhaust ventilation (LEV) is one of the main measures used to control worker exposure to hazardous substances. It’s difficult to work out exactly how many systems there are in Britain, but the Health and Safety Executive carried out some research in 2006 and estimated that there were between 260,000 and 330,000 businesses that have

Practical Management of LEV Controls

Practical Management of LEV Controls is a new one-day  BOHS Approved Course developed in conjunction with HSE. We’re going to be running it later this year, details as follows: Date 15th September 2011 Venue Chester Cost £195.00 excluding VAT per delegate – includes course documents, lecture fees and lunch.

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

Glove boxes

Glove boxes are often used in the pharmaceutical industry to control highly toxic “active” agents used in drug formulations. In principle they should provide a high degree of protection for the user. The contaminant is completely contained inside an extracted enclosure while the worker is outside. So when we’re carrying out a risk assessment and

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

Partial enclosures – keeping contaminants out of the user’s breathing zone

In a previous post I discussed why captor hoods are ineffective at controlling contaminants generated by most common industrial processes. Partial enclosures, or booths, are another common type of hood which, in principle, should be more effective  for many situations. This is because they don’t have to actively capture the contaminant as it’s generated inside the

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