Scola air drying clay sulphur free???

As google search results tend to show mostly ads and businesses rather than useful results, I thought I'd throw myself to the mercy of you affable ladies and gentlemen.

I am making a full sized Hippogriff (Harry potter creature) bust and am at the point of sculpting the eyes and the beak. I'd like to use scola air drying clay (as it's cheap) and then silicone mold with a resin cast. Is scola air drying sulphur free?

If not, is there a way of sealing the clay so that it won't react to the silicone?

Look forward to any help offered. Thanks.

Says nothing about sulphur, butt its Gluten and wheat free!...nothing about sulphur, which doesn´t mean it´s not in it.

http://www.scolaquip.co.uk/air-hardening-clay.html

Their safety data sheet (no tech bulletin) says nothing about sulphur: either:

http://www.scolaquip.co.uk/assets/air-drying-clay-sds-081014.pdf

If you really want to use it, I´d get in touch with them directly and ask...or just make a small test if it´s a cheap prduct. Even if they said there´s no sulphur I would test it anyway.

Good luck and tell us what you found out!

Thanks for the response! I've emailed them but will try a small test today as you suggested. Wish me luck!