The largest RV dealer in Boise Idaho only blows out the lines and does not ad RV antifreeze and they service RV's clear to McCall Idaho that gets to -20+ yearly.I have never frozen just blowing out my lines as taught by the RV foreman there..To each his own...

People complain about water taste in there RV yet they fill there tanks with the garden hose instead of an RV hose and fill there lines with antifreeze.

This is from Prestone RV antifreeze.....

Quote
INHALATION: No adverse effects are expected, however, if irritation or
other symptoms develop, remove to fresh air. Seek medical attention if
symptoms persist.

SKIN CONTACT: Remove contaminated clothing and wash skin with soap and
water. Seek medical attention if irritation develops.

EYE CONTACT: Immediately flush with water, holding open eyelids, for
15 minutes. Seek medical attention if irritation persists.

INGESTION: If swallowed, get immediate medical advice by calling a
physician, poison control center or emergency room. If advice is not
available and a significant quantity has been swallowed, give 1 or 2
glasses of water or milk and induce vomiting. Take the victim and the
product container to the nearest emergency treatment center or
hospital. Do not attempt to induce vomiting or give anything by mouth
to an unconscious person.


As I said..To each his own.....

Jayco