I've used polyester resin alot (you can tell.. ) but i think that the safety information is a bit exagurated. You don't really need a full ventilation suit. But i would recommend a change of clothes becuase the smell clings to you like ciggarete smoke. But yes, you do need a ventilation MASK or atleast work outside (with mask) where there is plenty of ventilation.
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And oh yes.. you'll probably want to get golves. i have a pack of Surgical gloves at home. Works fine for me.
Resin is a very generic term. All polymers have a resin, and a catalyst. Resin can be polyester, epoxy, urethane...
The term "resin" generally applies to Urethane casting resin, but could also mean polyester fiberglassing resin.
Either way, the fumes are dangerous and precautions need to be taken. A full chemical respirator, eye protection, and gloves are a must. Wearing old clothes is a good idea, as you always get it on you.