Thanks both of you.
I saw the safety data sheet before too. However I strongly doubt that all the warning sign in that note will have a soothing effect on the museum.
I had a futile wish that a at least one D.o.P out there had a prior Ph.D in toxicology and great interest in shooting smokey art and published articles containing extensive test on the matter...Dooh!
Let me know if you find something more I will keep digging.
/Pelle