Reminder: Policies and good practices...

Mary Tang mtang at
Thu Jun 30 17:14:18 PDT 2005

Hi all --

A couple of safety & policy questions have come up, so on behalf of Uli 
and other staff, I thought I'd take the opportunity to clarify them.

1.  Please enable wbgeneral and wbgaas, even if you are not using 
functions (hot plate/bath) that require enabling.  Yes, this means that 
there is a fee even if you just leave a beaker there, but please realize 
that there is also a resource cost to the lab and other users of the 
bench (chemical disposal, space, etc.)   wbsolvent and lithosolv 
benches, however, do not need to be enabled unless you use the hot plate 
or ultrasonicator.  This is because people need to soak devices, 
especially for lift off.  Also, there's only a few chemicals involved.  
At wbgeneral/wbgaas, there are a lot more chemicals used and workspace 
is critical for safe operation - so please enable any of the hotplates, 
even if you do not use one, if you plan to soak a device there.  If you 
really need a long-term area to soak your device, there are other 
alternatives on campus and in the building.

2.  Please use a blue card for any container with a chemical, even 
water.  I hope everyone understands why.

3.  Do not pour chemicals down the sink drain.  For two reasons - 
First,  a chemical (like sulfuric acid) which heats when mixed with 
water could explode from a sink drain if not properly diluted.  By 
aspirating, the solution is quickly diluted and cooled at the same time 
- and removed from the bench area.  Second, the sinks were not designed 
to be used for dumping chemicals and may not be entirely covered by 
exhaust.  This means that by pouring down the drain, chemical fumes will 
enter into the main area of the lab, only to be recirculated through the 
air system.

Thanks for your attention -- and if you have any other suggestions for 
improvement or comments about these stations, please let us know.


Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
mtang at

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