KK,
Here are some links to sites about argon gas, you will need to know what grade argon you are using:
1st is a link describing MSDS sheets
2nd is a link to MSDS sheets on argon gases (you have to enter argon gas in the search field)
http://www.ilpi.com/msds/osha/I19950125.html
http://msds.pdc.cornell.edu/msdssrch.asp
Hope this helps,
John Wright