Dear Birck Cleanroom Users, As the new cleanroom fume hoods have come online and are being used for research operations we've observed some very concerning issues. Some fundamental air-flow issues remain and we're working on solutions but more concerning is the performance of the hoods when used with chemicals. The hoods have a design flaw that uses vent holes in the upper work surface, venting the lower cabinet area through the hood exhaust. These vent holes are located in areas where chemicals and rinse water can leak through the holes and flow into the cabinets below. Puddling in the lower cabinets has been seen in almost all hoods, indicating that these holes are leaking from the upper deck. We've measured the pH in a lower cabinet and it was clearly acidic indicating that more than water is leaking into the storage area. Therefore, due to safety concerns, we are shutting down all the hoods immediately until a plan is developed by the hood supplier and the construction management to remedy these issues. We apologize for this inconvenience, but the safety of all our users is clearly the top priority and we can't continue working in unsafe hoods. We will work with the construction company and fume hood vendors to find a safe and effective solution as soon as possible. Until then the cleanroom hoods are not available for use. Thanks for your understanding. Ron