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Subject: Re: [DCHAS-L] Nature Comment Pregnancy in Lab
Date: Monday, February 14, 2022 at 1:07:39 PM
Author: Ralph Stuart <ralph**At_Symbol_Here**rstuartcih.org> 		Next by Date:
Subject: Re: [DCHAS-L] Nature Comment Pregnancy in Lab
Date: Mon, 14 Feb 2022 10:27:36 -0800
Author: neal**At_Symbol_Here**chemical-safety.com

From: Info <info**At_Symbol_Here**ilpi.com>
Subject: Re: [DCHAS-L] Chemical Safety headlines (10 articles)
Date: Mon, 14 Feb 2022 13:15:21 -0500
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID: 9B13B2DD-E5B8-45A0-AE4A-215ABA224D06**At_Symbol_Here**ilpi.com
In-Reply-To <905015534.2029079.1644858734409**At_Symbol_Here**mail.yahoo.com>


On Feb 14, 2022, at 12:12 PM, Monona Rossol <0000030664c37427-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU> wrote:

As long as activists waste their time, energy, and money banning individual bad-actor chemicals,

The EPA needs to take a nod from patent law, where the owner of the intellectual property needs to think about the end runs that someone might make around their composition of matter claim.

To use a personal example, when we patented our rhenium olefin metathesis catalysts, we had to figure out how to keep someone from infringing by doing 'ole methyl, ethyl, butyl type substitution.  The Patent Office won't let you broadly claim, for example, R = any alkyl or aryl group, so you have to be narrower than that.  But you can be broad while being narrow… https://patents.google.com/patent/US5146033 

We had two alkyl groups in the catalyst so we defined R1 and R2 as:

R1 is selected from the group consisting of an alkyl having 1 to 20 carbon atoms, an aryl having 6 to 20 carbon atoms, an aralkyl having 7 to 30 carbon atoms, halogen substituted derivative of each and silicon-containing analogs of each; R2 is selected from the group consisting of R1 or is a substituent resulting from the reaction of the Re=CHR2 moiety of the compound with an olefin that is being metathesized;

Examples of R1 and R2 include but are not limited to phenyl, t-butyl, 1bethyl-1-phenyl-ethyl, trimethylsilyl, triphenyl, methyl, triphenylsilyl, tri-t-butyl, tri-t-butylsilyl, 2,6-diisopropylphenyl, 2,4,6-triisopropylphenyl and 2,6-dimethylphenyl.

For the two alkoxides, R3 and R4, we actually got away with the obvious choices and also talked about the *properties* they would have. 

R3 and R4 are individually selected from groups consisting of R1, a halogen, triflate, and concatenated combinations of R3 and R4, wherein R3 and R4 individually may contain alkoxide oxygen atoms which are bound to the rhenium atom; n is a positive integer (preferably one or two); and provided that when R1 and R2 are t-butyl and R3 and R4 are the same, then R3 and R4 are groups other than t-butoxide, trimethylsiloxide, neopentyl or a halogen.

The remaining two ligands (R3 and R4) can be any substituent which is sufficiently electron withdrawing enough to render the complex active (i.e., render the rhenium atom sufficiently electrophilic) for metathesis reactions. While it is preferable that both ligands are electron withdrawing, the compounds of this invention may contain only one electron withdrawing ligand which is sufficiently strong enough to render the complex active for metathesis.

Preferably, R3 and R4 are both alkoxide ligands in which the alcohol corresponding to the electron withdrawing alkoxide ligands should have a pKa of about 9 or below. Suitable electron withdrawing ligands which fall within this range include phenoxide, hexafluoro-t-butoxide and diisopropylphenoxide. Other examples of preferred electron withdrawing ligands include alkoxides containing 2,6-dimethylphenyl. 2,4,6-trimethylphenyl, 2,6-diisopropylphenyl, pentafluoro, phenyl, 1-methyl-1-phenyl-ethyl, 2,6-dichlorophenyl, perchlorophenyl, triphenylmethyl, triphenylsilyl, tri-t-butylsilyl, perfluoro-2-methyl-2-pentyl, trifluoro-t-butyl (CF3 (CH3)2 C), hexafluoro-t-butyl ((CF3)2 CH3 C) and perfluoro-t-butyl. Examples of concatenated R3 and R4groups are pinacolate, 2.6-dimethyl-2,6-heptanediolate and propan-1,3-diolate.

So I would suggest that in that same vein, EPA could in theory add language of "or analogs reasonably expected to have similar pharmacokinetic/environmental/toxicological properties, belonging to a class of known carcinogens/endocrine disruptors etc. etc." unless something in the law specifically prohibits that. I would imagine the litigation attacking any such determination would be lengthy and extensive - it's bad enough now for single compounds - think TSCA, for example. http://www.ilpi.com/msds/ref/tsca.html   Industry would no doubt kill any bill that permitted this approach.

But it's nice to think about.

Rob Toreki


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