Extension for a 3/8 drive butterfly wrench

[ps4330@okc01.jccbi.gov (Peter Schauss x 2014)]

I just bought a butterfly wrench with 3/8 drive and 
a set of impact wrench sockets.  I tried also to buy
an extension for the tool, but the only ones available
are for 1/2  drive tools.  The salesman told me that
the amount of torque that the wrench delivers was
small enough that I could use a standard extension.

1.  Is he correct?  Is it safe to use a standard
3/8" drive extension?

2.  If not, any suggestions where I can get a 3/8
drive impact wrench extension?

Thanks,

Peter Schauss
ps4330@okc01.jccbi.gov
schauss@worldnet.att.net
1963 BJ7
1980 MGB