Lifefactory12 Ounce LG4121BIR4

Q: Is this bottle 100% leak proof? Is there 0 contact of water with plastic? What materials come in contact with the water?

100% leak proof so far for me & seems very secure although I do not store the bottle floating around in a bag. The bottle is thick glass The plastic sleeve is on the outside and does not come in contact with the liquid. The screwtop would not touch the liquid at all while drinking but the top with the straw or the low flow top or pop top Would come in contact with the liquid while drinking. Love these, I have purchased four with three different tops.