Q-tips w/resist in the regular trash??!!!?!

Mary Tang mtang at stanford.edu
Mon Feb 13 18:00:50 PST 2006

Hey!  Who put resist-contaminated Q-tips in the regular trash this 
weekend?  Do you realize what chemicals are in the resists?  Haven't you 
read the MSDS for the resists in the lab?  Don't you know that:

1.  Most resists are based on ethyl lactate as solvent?  Although this 
is considered in the industry to be a "safe" solvent, it's only because 
the previous ones were nastier.  The PEL (Permissable Exposure Limit) 
for ethyl lactate is actually the same (5 ppm over an 8 hour period) as 
that of chlorobenzene and the glycol ethers -- the "not-safe" solvents 
(and do you know why?)

2.  How to get rid of resist-contaminated waste?  It should be placed in 
air-tight bags and then placed in the designated resist and solvent 
waste container.  Leaving them in the regular trash means that everyone 
in the lab has to breath the vapors -- and since cleanroom air is mostly 
recycled, we are all breathing it and rebreathing it for a loooong time.

Now, STOP IT!!!

Mad-eye Mary

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

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