Thanks JR! I've been hoping to find some information on Sierra Antifreeze, and this gave me reason to be glad that I decided to use it in my new (and future) cooling system........ thanks again.
from link:
As an alternative, automotive chemical manufacturers have formulated a newer type of antifreeze using propylene glycol (PG) instead of ethylene glycol, which is less harmful if accidentally ingested. A popular brand is SIERRA=AE, which was the first nationally marketed propylene glycol based antifreeze. =A0=A0 Safer, propylene glycol based antifreeze provides performance and protection comparable to conventional ethylene glycol based antifreeze in four key areas of engine protection: boil over, freeze-up, corrosion and heat transfer. SIERRA=AE, and other propylene glycol based antifreeze products are available nationwide, and can be the extra margin of safety to protect your children, pets, drinking water, and neighborhood wildlife.