Tiny TwinkleMess-Proof Apron Toddler Bibs w/Tug-Proof Closure, Baby Food Bibs, 2 Pack

How long do they take to dry (when hung?)

My son is 20 months old. Is this true to size? Not sure if I should get the 6-24 or jump to the 2-4 yo?

What's the size difference between the Small and Large? The image shows the same size for both.

Do these contain flame retardants? Are they tested for those?