There are several hazards to be considered prior to shaping a surfboard, below are some factors that will make your shaping experience a whole lot safer.
Location
Ensure that your shaping bay is located far away from residential dwellings, as the by product of shaping tends to go everywhere. I would NOT recommend garages attached to houses, attics or basements. The toxic chemicals and dust can easily spread into the living areas and will be damaging to you and your families health. I use the shed at the rear of my block, which is perfect due to it's isolation from my home.
P.P.E
The smell of Polyester resin in particular is known to linger in peoples skin and hair, even after showering. I would suggest using a full body chemical-resistant painters suit, with a hood to cover your hair.
Invest in a high quality dust/gas mask for use when sanding and glassing. You don't want to be breathing in foam particles or toxic resin fumes.