Re: Krytox flourine a problem?

Ballendo:
Krytox is not a safety problem, but I wonder why people think they
need to use this grease. It is a hard to clean up and
it is expensive. The solvents used to clean this up are the
perfluoroalkanes or trifluorotoluene also called
trifluoromethylbenzene. I'm not sure if the perfluoroalkanes
or the trifluorotoluene is cheaper. I would use the trifluoro-
toluene since it dissolves regular hydrocarbon greases too.
I used this stuff in the lab for my glassware at one time
and it's used if you are worried about water or oil leaching
your grease out of your bearings (?) or glass seals. It was
good for that, but you were in for a real treat if you wanted
to clean the stuff up! Since this stuff is sticky, it still
picks up dust, dirt and metal chips.
The only danger is the burning of this grease or teflon. This
forms difluorocarbene and other similarly reactive species.
Difluorocarbene forms difluorophosgene in the presence of oxygen.
Difluorophosgene is the fluorine analog of phosgene (made famous
in WWI).
If the original engineers don't recommend the use of this
grease, then I would not use it. -Jim



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo" <ballendo@y...>
wrote:

> Vince,
>
> Glad you brought this up...
>
> According to the Krytox MSDS (govt. mandated Material Safety Data
> Sheet), you don't have to worry about flourine except in cases

where

> the temperatures exceed 500+ degrees F.
>
> Skin contact can be irritating, but only as a rash. (I've never
> experienced this, but it's on the MSDS)
>
> No carcinogens, basically inert stuff.
>
> You don't want to be careless with this stuff, but at the price

you

> prob'ly won't be!<G> As long as you are careful about washing

hands,

> cleaning clothes, and keeping things below 500 degrees, you should

be

> okay. And good ventilation is a good thing in ALL machining
> operations!
>
> Hope this helps,
>
> Ballendo
>
> P.S. There has been some concern about teflon coated baking pans,
> which ARE used at elevated temperatures... Also about aluminum and
> its relation to Alzheimers. Be informed, keep clean, and be

careful...