[pcm81]

How bad is 1% solution of HF? I was helping my mom clean the driveway rust stains, using some "weak" chemicals, when our neighbor walked over and offered to help. He brought over this nice rust remover poured on the driveway rust stains and it worked very well. So I looked at the list of active ingredients and my jaw dropped. Active ingredients are oxalic acid and hydrogen fluoride. Looking at actual msds sheet it says less that 1% concentration, but still surprised to see HF in $10/gal solution available at Wal-Mart.  No spills happened, no exposure or any other oopsies, but I am just curious how bad can it be... I bought 3 gallons of that same cleaner to finish driveway cleaning next week. Usually I'd not use things this bad unless I need to, so might still go with HCl instead of this cleaner. Just curious how careful should I be with 1% solution.  Goof off rust stain remover is the actual product if anyone wants to look up msds. It basically states HF <1% and oxalic acid  <10%.

[jeffmoonchop]

Not answering the HF problem here but the oxalic acid is used as a kitchen pan cleaner when normal washing fails to remove tough stains. I used a lot of oxalic acid in my PhD and I know its toxic due to being a main ingredient in kidney stones. i.e. causes kidney failure. I'd wear thick rubber gloves when using it if I were you.

[P]

I'd wear thick rubber gloves when using it if I were you.

msds. It basically states HF <1% and oxalic acid  <10%.

What does the SDS suggest regarding PPE?    I do not know how bad HF is at 1%.  Presumably not as bad as it is in higher concentrations or they probably wouldn't sell it so flippantly to the public without strict instructions to wear gloves and goggles and breathing kit on the can.

[pcm81]

Thanks all for replies.
according to wikipedia the LC50 for F is ~1200 ppm comare that to like 3400 for Cl...

Was just surprised to see HF in OTC products at all....