The bubble could then be removed from the straw by pinching the hole closed, sealing the air inside. The fumes could become concentrated inside the straw, making it dangerous to inhale through the straw while inflating a bubble. Besides the potential for spills when liquid plastic was handled by children, the substance also emitted noxious fumes. Roughly the consistency of bubblegum, the bubbles formed were much more durable than simple soap bubbles, and could be gently manipulated to make different shapes, and stacked to make simple figures such as snowmen. It consisted of a tube of viscous plastic substance and a thin straw used to blow semi-solid bubbles.

Bloonies Magic Plastic Bubbles Variety Pack (96 Tubes in 12

However, they were not as durable as regular balloons, and could pop easily if overinflated, handled with too much force, or squeezed.One end of the straw was then inserted into the ball, and the user would blow into the other end, inflating the plastic into a bubble.

Super Elastic Bubble Plastic - Wikipedia

Super Elastic Bubble Plastic was the brand name for a children's toy manufactured from the 1970s through the 80s by Wham-O.