DCHAS-L Archives, Oct 13 2017 - Re: [DCHAS-L] HF concentration and gluconate gel

>>You want to go down to the auto parts store, you can buy 6-13% HF as a cleaning agent for "chrome wheels" or as a rust remover.

On a recent inspection of a makerspace/shop area, the inspection team encountered a glass Mason jar with a hand-written label on a piece of tape stuck to the jar which read "Ti etchant - HF." We wondered what that abbreviation could mean - surely not hydrofluoric acid. Investigation revealed that the product was a "Rust Stain Remover" whose SDS does indeed indicate 1-2.3% hydrofluoric acid in the product. Not surprisingly given the nature of the space, the area where this container was found is not equipped to use HF, neither appropriate PPE for HF use nor calcium gluconate gel was available, and rather obviously users were not trained in use of HF; if they had been, they hopefully would not have stored an HF-containing product in a glass container. I was quite surprised that a product containing up to 2.3% HF is just commercially available out there in the world for anyone to buy (I thought "muriatic acid" (aka HCl) at Home Depot was bad enough!) but such is our world and our life as safety professionals, I guess.

Earlier in my professional life when sampling chemicals from etchant baths at a microtechnology fabrication facility, there were multiple dilution levels of HF used and we treated them all as just as potentially hazardous as 49% HF (which the facility also used).

At MIT, HF-use areas need calcium gluconate gel, stored in a prominent location that HF users know and are trained on. Checking the presence of the gel and the fact that it is not expired is an Inspection question on the semi-annual inspection checklist. MIT EHS provides the gluconate gel to labs with no cost to the labs at point of service. Of course there's no such thing as a free lunch, the cost comes out of overhead charges somewhere, but I do not know the details of that arrangement.

Thanks as always for interesting discussions on the DCHAS-L and I hope everyone has a good weekend.

Dan

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Daniel C. Herrick, CIH

Senior EHS Coordinator

Mechanical Engineering Department (MechE)

Massachusetts Institute of Technology (MIT)

Email herrickd**At_Symbol_Here**mit.edu

Web http://mecheehs.mit.edu

http://ehs.mit.edu

Office 3-449g

Phone 617-253-2338 (MIT: x3-2338)

From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Alan Hall
Sent: Friday, October 13, 2017 11:49 AM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] HF concentration and gluconate gel

Jeff, Harry, et al,

I am a physician and a medical toxicologist and one of my particular interests is HF.

You want to go down to the auto parts store, you can buy 6-13% HF as a cleaning agent for "chrome wheels" or as a rust remover. There's a phosphoric acid product also avaiable.

I had a patient one bought one of these "rust/stain removers" and used it for 8 hours to clean windows in her house (no accounting for tastes - surprised the glass wasn't etched), didn't wear any gloves, and went to bed. Woke up in the middle of the night with really, really bad pain inher dominant hand. Dilute HF may not cause pain for several hours after exposure, but it is all out of proportion to the obvious clinical appearance.

Didn't want to wake up her primary care physician, so toughed it out until office hours. Told him she had used a usual windown cleaner. He treated her as an allergic reaction.

By the time we figured out it was HF, she lost her thumb and the first 2 fingers of her dominant hand.

Now, could probably be prevented. Stuff I can't discuss on this listserve, but we did do some good research on calcium gluconate at the Rocky Mountain Poison and Dru Center where I trained.

So my recommendation would be that whatever concentration HF you work with, having calcium gluconate gel available as a first aid measure would be a very good idea. Many employers provide 3 tubes: 1 in the worker's pocket, 1 in his/her locker in the changing room, and 1 in he medicine cabinet at home. To be used by inunction as soon as pain is perceived and then immediate going to whatever healthcare facility the employer uses, hopefully with prior instruction that HF is not "just another acid -- it can not only burn you, it can KILL you. I don't ever want to get another call about "our patient just died, can you tell us why?". (HF mistaken as being HCl.)

Alan

AlanH. Hall, M.D.

Medical Toxicologist

On Fri, Oct 13, 2017 at 10:28 AM, Harry Elston <helston**At_Symbol_Here**midwestchemsafety.com> wrote:

Jeff,

I'm not a physician here, but here's my take:

Regardless of concentration in-use, having it on hand provides for good first aid practices.
How did the end-user get to "low concentration?" Did they dilute a higher concentration solution?
"Low concentration" tends to become "higher concentration" use over time because (nearly) every scientist believes "more is better". My observation of scientist nature over time. That circles the logic back to #1 above.

Honeywell's guide does give cutoff concentrations to define "dilute."

H

From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Jeffrey Lewin
Sent: Friday, October 13, 2017 9:47 AM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: [DCHAS-L] HF concentration and gluconate gel

I received a cold call for gluconate gel kits this morning that I sent on to departmental CHO's. Someone asked if they should have kits available for low concentrations of HF (<0.1%).

Does anybody have a HF "cutoff" where they don't require/recommend kits be immediately available in the laboratory?

Jeff

--

Jeff Lewin

Chemical Safety Officer

Compliance, Integrity, and Safety

Environmental Health and Safety

Michigan Technological University

Houghton, MI 49931

O 906-487.3153

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