George, here's some info I extracted from the MSDS on West Systems resin regarding inhalation of vapors.

POTENTIAL HEALTH EFFECTS:

ACUTE INHALATION: ......................................... Not likely to cause acute effects unless heated to high
temperatures. If product is heated, vapors generated can cause headache, nausea, dizziness and possible
respiratory irritation if inhaled in high concentrations.

CHRONIC INHALATION:.................................... Not likely to cause chronic effects. Repeated exposure to
high vapor concentrations may cause irritation of pre-existing lung allergies and increase the chance of
developing allergy symptoms to this product.