Rotary evaporators can be spotted in labs under fume hoods or directly on benchtops. While both options are valid, there are multiple factors that need to be taken into account when deciding whether to use a fume hood or not. This blog post puts everything on the table (or benchtop) to help you answer the age-old question: to fume hood or not to fume hood?
1-Using the Right Equipment
We know, it’s an obvious one, but if your set up is too big to fit under the fume hood, you won’t be able to use it. Your choice of hood usually boils down to the amount of space available in your lab: if your condenser is vertical, you will probably need a larger fume hood as compared to diagonal condensers that are more “space-friendly”. Both ways, safety always comes first, so we’ve compiled multiple criteria to help you make the right choice when deciding whether or not to purchase a fume hood.
Implosions are most likely to occur if your glassware has cracks or fractures in it. When the glass is put under different stressors, it’s prone to break, which might lead to injury. In that case, it is advised to keep the sash closed at all times.
Some applications of your rotary evaporators come with a risk of explosion; this includes but isn’t limited to the use of different chemical mixtures that carry a high risk of explosion when put under certain conditions. For instance, multiple reports have emerged recording the presence of azide with the use of halogenated solvents leading to explosions shattering the glassware of rotary evaporators.
If an explosion was to occur, bystanders would be at risk of exposure to chemical splashes and being hit by flying glass shards. Using your rotary evaporator with your fume hood’s sash always closed is one of the easiest ways to mitigate the risk of different injuries caused by an explosion.
Another reason why you might consider getting your rotary evaporator a fume hood is high temperature applications. Say you’re using an oil bath and you’re heating it to temperatures at or above 100°C to perform a high-temperature evaporation; leaving it unattended might pose a prominent safety concern. You might be wondering what the best way is to mitigate that risk, and you guessed it: fume hoods.
5-Health Risks due to Fumes
Rotary evaporators should be used in well-ventilated areas. Removing volatile solvents is not a risk-free process: sometimes volatiles escape, and if present in high concentrations, might lead to explosions, irritation, and/or different respiratory illnesses. Sometimes, proper ventilation might not be accessible in your lab. In that case, once again, fume hoods are the answer.
It’s worth mentioning that some applications of your rotary evaporator might lead to the generation of toxic fumes or vapors. In that case, no matter how well ventilated your lab is, fitting your equipment under a fume hood becomes a necessity.
Getting the Job done without a Fume Hood
For whatever reason, getting a fume hood for your lab might not be an option. However, compromising your safety isn’t. That’s why we added a couple more alternatives to using a fume hood that provide you with the protection and ventilation you need to carry on your work in your lab worry and risk free.
1-Building a Safe Environment
Building a safe environment starts with you donning the right Personal Protection Equipment (PPE) if handling hazardous materials. Having the proper measures implemented inside of your lab if operating in special environments is also worth considering. For instance, certain applications should be carried out in labs that have preexisting built-in ventilation systems, and that are fully explosion proof.
2- Using an Enclosure instead of a Fume Hood.
Enclosures can be a great alternative to using a fume hood in your lab when trying to minimize exposure to fumes and vapors. It is worth mentioning that not all enclosures provide protection against both vapors and shattered glassware/ splashes,
Fume hoods serve one main purpose: minimizing exposure to the different risks you might be exposed to when using your rotary evaporator, namely noxious vapor and fumes, and flying shards of glass caused by implosions and explosions. Other options to consider when fume hoods are not available are either using an enclosure, or carrying out your experiments in a pre-made special environment.