Recirculating fume cabinets (ductless) are very useful, but they do have limitations and these must be recognised in order to operate them safely and effectively. The standard that covers these fume cabinets is AS/NZS2243.9 and this contains a great deal of information on the operation of these units. The Following is a quick guide, but it must be stressed that there are a lot more directives in the standard that must be followed.
- Anyone operating a recirculating fume cupboard must have been trained in its use and features before starting any work.
- A log book SHALL be kept for each fume cabinet, listing the
date, hours used, the chemicals and volumes or amounts used.
It should also list any incidents, particularly spills and filter change dates.
- If the fume cabinet does not have an automatic air flow alarm and filter
break through detection system it SHALL be tested once per month for
both airflow and filter performance.
- The fume cabinet must be tested for electrical safety once a year.
When using a cabinet with an activated carbon filter:
- No more than 50 ml per day of evaporative solvents that are only physically absorbed on to the filter media and with a
boiling point lower than 75 degrees c. Definitely no products with anaesthetic properties
- High temperatures and high humidity adversely affect the filters performance so should be carefully considered prior
to any procedure.
- There is a maximum limit of 50 ml of liquids involved in a reaction that will generate corrosive fumes.
- Maximum recommended filter life of 2 years in very light use environments
- In heavy use applications, the filter will need to be tested for breakthrough on a regular basis and will possibly need
changing more often.
- Locations for the fume cabinet must still comply with standard practices for traffic routes, airflow disturbance, bench
spaces and architectural features.
- If the fume cabinet is moved, a full recommissioning test must be conducted before it is used again. This must be
documented and the records kept in an easily accessible place. A copy of the spacing diagram from the standard must
be kept with the fume cupboard. All testing must be undertaken by a competent person using equipment that has a
current calibration certificate.
There are other aspects to the standard and a responsible supplier will inform you of these.
Following these guide lines will help to keep everyone safe and in conjunction with regular preventative maintenance will help to extend the working life of the fume cupboard. If you have any questions please do not hesitate to contact us.
