Fume cupboard

1. Before using the fume hood, it is the duty of the user to carry out a check of the fume hood, it can be a daily check, several times a day or once a week, depending on the type of work carried out in the laboratory.
2. Visually check the fume hood if it is intact, including whether it has been cleaned after the last use.
3. Check if the technical installations (eg water, gas, electricity) work if they are to be used during work.
4. Open the sash slightly - check if there is suction in the fume hood, use a flow indicator on the sash so you can clearly see the air being drawn into the fume hood.
5. Check if the light and sound signals are working. Open the sash to maximal height, whereby a red light should be turned on in the light panel and an alarm should sound. Then lower the sash to working height and the alarm should stop and the green light is turned on once more.

In order for the fume hood to be well -functioning and safe to use, good laboratory practice for fume hood must be complied with, see the guidance here.

Annual technical functional test

• Facility Management conducts an annual technical functional test of the fume hood. Facility Management can delegate the test to an external firms.
• Facility Management must plan the time for techincal functional test in collaboration with the Health and Occupational Safety organization at the relevant institute.
• All fume hoods must have an airflow velocity at the sash opening of at least 0.5 m/s regardless of the height of the sash opening.
• If the air flow deviates more than 10% from previously measured values, a trace gas analysis is supplemented.
• A log must be kept of the results of all tests of the fume hood, log or elctronically in Dalux. .

1. Stop the work immediately – and stop any experiments!
2. Put lids on packaging and chemicals and remove them if possible to another fume hood or chemical cabinet.
3. Close the sash completely down!
4. Put the ”Out of order” sign on the fume hood window.
5.  Report the failure to Facility Mangament using Dalux.

Guidance out of order can be downloaded here

Dalux on the mobile phone:

1. Download Dalux-App and Press The Icon to open the app.
2. Click on"Ny indmelding",
3. Scan the QR-code, which is located on the fume hood,
4. Choose "Hjælp til inventar",
5. Fill out the form "Beskrivelse" with the error and
6. When you are done, click on the green button ’Send’, and you will receive a confirmation.

If you do not have a smartphone available, you can instead register using the Dalux HelpDesk web portal:  Dalux FM Helpdesk:

1. Go to the web portal, via the link above, 
2. If this is the first time you log in, you need to fill in your contact information "Email", "Name" and "Telephone number", 
3. Click on large green button "Indmelding",
4. Fill in "location" with the building number and "room" with the room number,
5. You need to categorize your request - click on "Hjælp til inventar",
6. Fill in "Beskrivelse" with a description of the error and 
7. When you are done, click on the green button ’Send’, and you will receive a confirmation.

The request has now been handed over to Facility Mangement, who will call in technicians to rectify the error. Facility Mangement will notify when the fume hood can be used again.

§20. carcinogenic chemicals:

§ 20. Work processes involving substances or materials may only take place in closed systems or in any other way that prevents the release of the substances or materials, so that any impact from this is excluded.

It is possible to work with §20 carcinogenic chemicals if the fume hood meets the requirements set in the described control program (installation test, annual function test and inspection by user), and that the fume hood is well functioning - see good laboratory practice for fume hood.

In a few cases in the period 2014-2020, Aarhus University has been ordered by the Danish Working Environment Authority to carry out trace gas analysis of fume hoods used for work with section 20 carcinogenic chemicals– at appropriate intervals.
Following the faculties' request to the Danish Working Environment Authority October 2020, the Danish Working Environment Authority has announced by telephone that they are not authorized to ask the university to perform trace gas analysis of fume hoods at appropriate intervals when the fume hoods are otherwise well-functioning.

Fume hoods or other ventilated units must be fitted with a control device indicating insufficient function.
If the amount of extracted air falls below the required air volume, an alarm is triggered in the form of a light and/or audible signal.

Aarhus University has decided that when using fume hoods, there must be an air velocity of 0.5 m/s.

The Danish Institute of Technology has shown that by lowering the air velocity from 0.5 m/s to 0.35 m/s, the safety factor is reduced by 500 times. Such a dramatic deterioration in the safety level supports the decision that the air velocity should be 0.5 m/s when working in a fume hood.

To save energy, the air velocity can be reduced to 0.3 m/s when the sash is closed and no work is done in the fume hood. It may be possible to turn off the fume hood completely if the fume hood is not connected to ventilation in e.g. chemical cabinets - provided that the fume hood is completely empty of equipment/containers that can release hazardous gases, vapours and aerosols.

Type Test 
Is performed by the manufacturer of the fume hood.

Installation Test - In house testing
Is performed by the supplier, who installs the fume hood, to ensure that the fume hood meets the applicable requirements set out in DS/EN 1417 + DS475 (trace gas analysis).

Routine Test - Annual Functional Test
Is conducted by trained staff from Facility Management, annually conducted and using calibrated equipment. Facility Management can delegate the test to an external firms.
In the event that airflow deviates more than 10% from previously measured values, a trace gas analysis is supplemented.

• A log must be kept of the results of all tests of the fume hood.
• Logs ans certificat must either be affixed to the fume hood in a logbook/file or saved electronic, e.g. in Dalux.

User control - inspection before use.
Performed by the user before using the fume hood, can be on a daily basis and even several times a day, by multiple users in the laboratory.

Trace gas analysis.

• When installing a fume hood, a trace gas analysis is carried out by the supplier, who also prepares a certificate that states whether the fume hood is suitable/not suitable for working with various chemicals.
• When installing a fume hood the trace gas analysis is carried out and paid for by the supplier.
• Certificate for the latest trace gas analysis must be available at the fume hood, either be affixed to the fume hood in a logbook/file or saved electronic, e.g. in Dalux.
• When relocating a fume hood and if there are significant changes in the use of the fume hood that may prevent normal air flow, a new trace gas analysis will be carried out, contact Facility Management.
• Other trace gas analysis are carried out by an external company at the institute's/center's expense.
   

Trace gas analysis and DS457:

In 2004, the old fume hood standard DS457 was replaced by the new standard DS/EN 14175, which is applicable throughout the EU.
As part of the new standard, fume hoods are type-tested at testing institutes before being sent out to individual laboratories. However, this is not a guarantee that the fume hoods function optimally in each laboratory in relation to the other installations and the geometry of the room, which can reduce the fume hood´s safety factor.
The Danish Working Environment Authority has maintained in their AT-guideline A.1.1 that the fume hood's extraction efficiency must be determined by trace gas analysis. This means that if a technician wishes to follow the AT-guideline, a trace gas analysis must be performed, which is why DS457 is still valid in practice.

Fume hoods play a crucial role in the laboratory environment, and their arrangement and placement should be carefully considered to ensure both efficiency and safety.

Fume hoods are set up in areas of the laboratory where there is not much traffic. Placement in corridors and by doors in the laboratory is not suitable for fume hoods, as it creates turbulence around the fume hood and thus impairs the safety of the user of the fume hood and other employees in the laboratory.

By following these guidelines, you can ensure an optimal function of the fume hood, as well as ensure a good working environment in the laboratory.