[greenbeer]

I will be doing a hydrogenation using palladium as a catalyst. I was wandering if their are any safe techniques or someone could point me in the right direction or recommend a book? I will be adding the catalyst in hydrogenator vessel. My concern isn't so much blanketing the vessel with nitrogen but actually weighing it beforehand. Thank you

[Dan]

It's not dangerous until it has hydrogen adsorbed (check the COSHH codes for 10% Pd/C).

It is after the experiment that there is a danger of the catalyst catching fire in the filtration step. Don't let it dry out on the filter pad, and once you have rinsed off your product, immediately slurry the residue in water and bottle it for disposal.

[DrCMS]

@Dan COSHH (Control Of Substances Hazardous to Health Regulation 2002) is UK legislation only and means not a lot to most of the world.  COSHH is the UK implementation of various new EU legislation along with previous UK legislation.

Also there is no such thing as COSHH codes.  I think you might have meant CHIP  or the newer CLP label codes.

Again these are not world wide; CHIP (Chemicals Hazard Information and Packaging for Supply Regulations 2002) is the older UK implementation of EU labeling rules and CLP (Classification, Labelling and Packaging Regulation (EC) No 1272/2008) is the current EU implementation of GHS (United Nations Globally Harmonised System).

Right now in the UK we're using both (CLP for substances but CHIP for mixtures) but from 1st June of this year the CLP/GHS system will apply to everything.

This might seem like an over the top reply but we all need to be clear what we mean when talking to people from around the world.  Your slang of COSHH codes would make sense to a UK chemist but on this board we are in the minority so be clearer in future. 

[clarkstill]

It's not dangerous until it has hydrogen adsorbed (check the COSHH codes for 10% Pd/C).

That isn't entirely true: I've seen Pd/C catch fire when added to a flask, prior to the addition of H2... It happened when a colleague added a large amount (2.5 g) of Pd/C to a large RBF. As the dust dispersed while it fell into the flask it caught fire, presumably simply due to the very large surface area in contact with air (the same reason flour dust is explosive!). However, Dan is right - it's generally not really a problem at the point of weighing out, just don't drop it from a great height so it disperses in air! You can just weigh it out with a spatula on the open bench, as you would with most solid reagents/cataysts.

[Dan]

This might seem like an over the top reply but we all need to be clear what we mean when talking to people from around the world.  Your slang of COSHH codes would make sense to a UK chemist but on this board we are in the minority so be clearer in future.

No, not over the top, I should have checked this - thanks for pointing it out.

[DrCMS]

Dan if only a few other people were half as grown up at taking constructive criticism as you the world would be a better place.

I went over the top because right now I am dealing with a CLP labelling query from one of our customers that is threatening to drag all of us under the bus.  I'm sure their expert is wrong and some of our other customers think he is wrong but at the moment he's not backing down.  If we have to do what he suggests it will either hit sales or require reformulating at considerable time and expense.

[Dan]

Dan if only a few other people were half as grown up at taking constructive criticism as you the world would be a better place.

I went over the top because right now I am dealing with a CLP labelling query from one of our customers that is threatening to drag all of us under the bus.  I'm sure their expert is wrong and some of our other customers think he is wrong but at the moment he's not backing down.  If we have to do what he suggests it will either hit sales or require reformulating at considerable time and expense.

That sounds rough, I hope it works out. It really annoys me when people can't admit their mistakes and I try not to be one of those people.

[greenbeer]

Thank you everyone for replies. The info seems consistent with what I've heard. I guess wet palladium would be more safer. I believe I have my basis covered, but I will be using about 38 psi hydrogen.  I've seen some standard university practices for loading the vessel as well as read Parr's general information, however it would be nice if their were some tutorials. Maybe theirs a good book about it? I will definitely take care when filtering. I read somewhere that their was some danger when releasing the pressure after the hydrogenation. If anyone comes across any links or book suggestions, I would appreciate it and Again thanks for the feedback