Hi everyone
I was having a chat with a technician about fume hood flow rates and raised the point of the safe but sustainable flow rate sitting around 0.35m/s-0.55m/s. The technician then raised a good point which asked if there was a similar safe but sustainable flow rate for biological safety cabinets and I was wondering if anyone knew if it was the same as fume hoods or if it differed?
It would be interesting to hear your thoughts and what you have been able to implement in your institutions. Similarly, if there has been difficulty implementing the flow rate changes or if lab members have been happy for the changes to occur.
Thanks and have a great weekend!
Naomi Martin
Queen’s University Belfast
Hello Naomi,
I asked our on site fume hood/safety cabinet specialist (we have him on site but he’s part of Laboratory Specialist Services) and his assessment is that it’s a very different situation and there is little to be gained from changing safety cabinet flows and a risk of H&S issues may arise. I’ve pasted his full answer below:
Hi Elisa, as discussed earlier.
Microbiological safety cabinet inflows are specified as follows.
MSC1 - 0.70 - 1.00 m/sec
MSC2 - >0.40 m/sec and downflow 0.25 - 0.50 m/sec.
All manufacturers must comply with these values to sell products, however, the minimum values do not guarantee a safe working environment within the enclosure for either the TC lines or the operator. To achieve a KI operator test pass, engineers may have to increase the inflow to a higher velocity. If this is lowered to achieve a slightly more sustainable lab energy usage it may pose a risk to the operator.
Thermo, Esco and Scanlaf already use digital fans in their equipment which reduces energy usage by a significant margin. Best energy saving for these cabinets is to turn them off when not in use and not use half speed setting (if this is an option on the MSC2).
Equipment owners could check if the service provider is keeping the cabinets as close to the manufacturers recommended airflows as possible.
I hope this helps!
Best
Elisa
Hi Elisa,
Thank you for coming back to me! That’s incredibly helpful, and some that I will pass on to all our technicians as this is good to know in terms of services. etc for safety cabinets. You’re very lucky to have an expert on-site for the fume hoods/safety cabinets, thank you for sharing my query.
Appreciate you asking on my behalf and sharing the expertise 
Naomi