Hello Everyone
I recently got a question from a researcher asking if EHS could confirm the disposal procedure for a synthesis where trimethyltin bromide is a byproduct.
The procedure was as follows: contaminated waste streams are separated into organic, aqueous, and solid tin waste that are specifically labelled and will be sent for disposal. The glassware can then contain residual contaminant, which will
be washed in bleach for >24 hours to oxidize any organotin species to tin oxides/hydroxides that are aqueous soluble (bleach washes are standard practice for heavy metal contamination of glassware and removes odors from volatiles). The glassware can then be
washed with standard procedures, and the bleach can be disposed of (good option for this is to have a specific tin bleach waste).
The Principal Investigator was on the email chain and provided the following information when I asked if there was any documentation of this method. “Unfortunately, this procedure (or any other for organotins) is not commonly available
in the literature. The aim here is to oxidatively decompose any organotin compounds so that they become water soluble (and these are only trace residue left on glassware, not a method to decompose the actual tin waste). Bleach is commonly used to treat all
heavy metals. Here is an example of oxidative cleavage of C-B bonds using bleach, and Sn is used as an analogous metal to B in our reaction (Stille vs Suzuki). Indeed, bleach is used to oxidize all organic compounds (alkanes etc) through complex free radical
approaches. This process is above and beyond a common procedure to just separate the waste streams and treat the glassware as safe even with residuals. The bleach ensures that any organotin residue is appropriately decomposed.”
This area of chemistry is beyond my expertise, and I was hoping another chemist could confirm that is the treatment with bleach is common or maybe another institution has a similar method in place for heavy metal reactions. I do not like
the idea of a “common” procedure that is not documented. The PI also provided some pdf documents email me directly if needed.
Thanks in advance,
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Jeffrey R. Cogswell, Ph.D.
Research and Chemical Hygiene Officer
Environmental Health & Safety
Dartmouth College
37 Dewey Field Rd.
Hanover, NH 03755
(o) 603-646-9355
