DCHAS-L Archives, Mar 31 2021 - Re: [DCHAS-L] Tetrabutylammonium Fluoride-Nasty, but Not Nasty Like HF?

One important thing to remember is that the US OSHA did not adopt all of the GHS SDS rules for products made or distributed within our country. This is particularly a problem in Section 11, Toxicology. Instead of blanks for all 10 required toxicity tests, they allow US manufacturers to just mention the existing data and say nothing else. So when you see, say, an LD50 reported but no other data, that is because THERE IS NO OTHER DATA.

An EU compliant SDS on this same substance would clearly state "no data available" in all those other 10 test blanks so the user would understand that they are working with a chemical that is untested for the other hazards. And remember that the laws in the EU are based on the precautionary principle which says in part: "in the absence of data you cannot assume a chemical is safe."

In the US, on the other hand, if you can't PROVE beyond a shadow of doubt that the chemical is toxic, the manufacturer can declare that it is safe and/or even "nontoxic." This is one of many reasons the EU (and 162 other countries) signed on to the GHS and why the EU gave us a June 2015 deadline to switch to the GHS system or they would no longer accept our exports. That's how OSHA got the only really new regulations in 20+ years without even a fight.

This all is particularly annoying to me when the "nontoxic" chemical on the US SDS is in a chemical class that any idiot would know could cause cancer if it was tested.

So if you really want to know both what is KNOWN and what is NOT KNOWN about a chemical, find a reputable US chemical exporter who has to meet the EU regulations. Sigma is a good one. Look at their Section 11s and that's a pretty good start.

There are also a flock of misleading statements that are allowed in the US and not elsewhere. One example is "safe if used as directed." But the important thing for users to know is the ingredient in the product and what could go wrong if it is not used as directed or some accident occurs. And to put that phrase on an SDS of an art or theater material is criminal since they KNOW their customers rarely use any product as directed.

Monona

-----Original Message-----
From: Franco, Jerry <Jerry.Franco**At_Symbol_Here**TTU.EDU>
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Wed, Mar 31, 2021 9:45 am
Subject: Re: [DCHAS-L] Tetrabutylammonium Fluoride-Nasty, but Not Nasty Like HF?

Thank you Sara for sharing your expertise!

From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU> On Behalf Of Sara J
Sent: Tuesday, March 30, 2021 12:42 PM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Subject: Re: [DCHAS-L] Tetrabutylammonium Fluoride-Nasty, but Not Nasty Like HF?

Afternoon,

The problem with SDS sheets is that there are a lot of variables that go into them and they are not highly regulated. A company's published SDS sheet is based on the software they use to author them, the available database, and any outside testing the company has done on their product. Product testing done by the company does not have to be shared and isn't always required by TSCA. So if there are two companies that sell the product and one has toxicological data and the other doesn't they may have different SDSs. I would look at section 11 in the SDS to see if there is published data on the SDS. If there is not PubChem is a good source for published tox data or REACH requires more data for registered chemicals, so look at ECHA's site. Based on the brief research I did TBAF has a LD50 Dermal of >2000 mg/kg, in comparison HF has an LD50 of <50mg/kg (making it fatal). This is most likely why you are not seeing the HF type warning.

On the other hand calgonate gel is not hazardous to the skin and it may work to neutralize any burns that would be caused by skin exposure to the chemical. So having it on hand may not be the worst idea.

Have a great day,

Sara Johnson, PhD, NRCC-CHO

Chemical Hygiene Manager

UNC Chapel Hill Environment, Health & Safety/Risk Management

FYI: I used to author SDSs for a small chemical company, so I have gotten really good at reading and interpreting them.

On Tue, Mar 30, 2021 at 12:58 PM Franco, Jerry <Jerry.Franco**At_Symbol_Here**ttu.edu> wrote:

Good morning,

You might want to compare SDS sheets with Chemwatch SDS. The SDS from Chemwatch says to treat skin contact with calcium gluconate gel. That's a red flag that we need to have calcium gluconate gel handy and signs posted warning people of the hazard. I am new to safety but I feel that this method is helping me catch things like this.

Which safety data sheet should we trust?

Best,

Jerry Franco

TTU Chemistry DSO

From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU> On Behalf Of TILAK CHANDRA
Sent: Tuesday, March 30, 2021 9:48 AM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Subject: Re: [DCHAS-L] Tetrabutylammonium Fluoride-Nasty, but Not Nasty Like HF?

I will recommend conducting a SciFinder search on the substrate when using TBAF as a reagent for a chemical transformation. There will be a huge difference in reactivity between HF and TBAF with different substrates. Anhydrous TBAF behaves not only as a potent source of nucleophilic fluoride but also as a potent base.

The following recent safety articles can be sources for the students to design the experiments and find suitable safety information when using the TBAF for chemical manipulations.

https://pubs.acs..org/doi/pdf/10.1021/acs.chas.0c00008

Lessons Learned=EE=83•Fluoride Exposure

https://pubs.acs.org/doi/pdf/10.1021/acs.chas.9b00015

https://pubs.acs.org/doi/10.1021/acs.chas.0c00108

Good luck.

Tilak

From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU> on behalf of Margaret Rakas <mrakas**At_Symbol_Here**SMITH.EDU>
Sent: Monday, March 29, 2021 2:32 PM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Subject: [DCHAS-L] Tetrabutylammonium Fluoride-Nasty, but Not Nasty Like HF?

Hi all-

We have a student project for advanced synthesis whose design include tetrabutylammonium fluoride (20-30%) in THF.. The SDS from the vendor, a large, trusted chem/bio supply company, plus checking on PubChem, indicates that while this is a corrosive (especially to eyes) and a health hazard, there is not the warning text that accompanies hydrofluoric acid or even ammonium fluoride-no indication for treatment with calcium gluconate gel.

Now I trust this company's SDS but given it's a fluoride compound, checked what I could and found corroboration of the hazard but no first aid requiring calcium gluconate. Can anyone explain why this material isn't quite as bad as HF or ammonium fluoride? Is it hindrance in penetrating bone from the tetrabutyl group or the low-ish percentage of the tetrabutylammonium fluoride in the solution or ???

thank you all!
Margaret

--

Margaret A. Rakas, Ph.D.
Lab Safety & Compliance Director
Clark Science Center
413-585-3877 (p)

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