Ventilated work stations
All labs have two fume hoods, most labs are also equipped with one or more bottom-ventilated and/or top-ventilated bench hoods as supplement.
|Respect times with reduced ventilation capacity
Weekdays 07:00 - 19:00, 100% capacity
Saturdays 09:00 - 14:00, 100% capacity
All other times = 50% ventilation capacity
Fume hoods are the most important piece of chemical safety equipment in the lab.
- All work with hazardous organic or inorganic chemicals must take place in a fume hood or equivalently ventilated work station.
- Look for these symbols on chemical labels and SDS's:
- Examples of chemicals ALWAYS handled in a fume hood:
- Toxic chemicals in dry form, very toxic and CRMS chemicals
- Volatile and flammable chemicals (solvents)
- Corrosive substances (concentrated acids and bases)
- Green arrows on the hood opening indicate the maximal sash opening. Opening the hood wider reduces the air flow, dramatically increasing the risk of exposure to chemical fumes, aerosols, or dusts that can escape the hood. An alarm will go off when the airflow is below the minimum limit.
- Do not handle toxic and flammable chemicals in the fume hood when the airflow is below the minimum limit (0,5 m/s).
- If experiments are ongoing, overnight, or chemicals are stored in the fume hood afterhours, the sash opening needs to be kept closed when ventilation is reduced to 50%, otherwise fumes will escape. Put a notice on the fume hood to warn others that opening the sash bears the risk of exposure to chemicals.
- An air flow monitor is installed in all fume hoods to monitor that it is working properly at all times. An alarm will go off if airflow is below the limit of 0,5 m/s. If you need to have the sash more open, you can override sound of the alarm by pushing the buzzer button. Do not do this when working with hazardous or volatile chemicals!! Never turn the monitor off, lower the sash to the minimum to prevent the alarm sounding during times of reduced capacity.
- Never turn the monitor off - use the buzzer function. Lower the sash to the minimum to prevent the alarm sounding during times of reduced capacity.
Ventilated Bench Stations
- Can be used for handling buffers and solutions containing hazardous chemicals (i.e. when work requires a microscope or other special equipment).
- Do not use when the ventilation system is running at half capacity
- Concentrated/ pure hazardous chemical should be handled in the fume hoods, as there are limitations to which chemicals can be handled in ventilated bench stations.
- Never store hazardous chemicals, buffers, waste bottles etc. in these stations!
Bottom-ventilated bench hood
- This workstation can be used for working with buffers and solutions containing hazardous chemicals that are heavier than air (formamide and formaldehyde).
- Not suitable for: Solvents that are lighter than air. Don’t use this station to evaporate solvents off tubes, flaks, samples etc.
Top-ventilated bench hood
- This workstation can be used for working with buffers and solutions containing hazardous chemicals that are lighter than air. Low concentrations of formaldehyde for fixing can be used in here (4% formaldehyde solutions).
- Not suitable for: Solvents/chemicals that are heavier than air.