Having just found out that its the proteins in latex which adhere to the powder inside and is dispersed when the balloon is used, i did a bit of surfing.
Latex allergies are on the increase which is a worry to all of us.
However, there is an alternative latex which is already being used to manufacture baby bottle teats, medical catheters etc
Its stretchy enough to be used for entertainer balloons altho they wont be available for one to two years from now.
Made from the Guayule (pronounced why you lee ), a desert plant, which is perennial so theres no replanting and the wood from these 3ft plants can be used, similar to maple.

This means entertaining in hospitals, supermarkets etc...
I cant wait