Your question was: Will the Exercise Ball burst? It has to be blown up at least 4" more according to the instructions and it looks already full.
Our experts said: It is important to follow all inflation and usage instructions as indicated in the instruction guide supplied with the ball. The following are suggestions for product care and examples of conditions which could cause your Thera-Band® Exercise Ball to break and should be avoided:
1. Clean you exercise ball using a soft cloth and warm, soapy water, but do not use abrasive or chemical cleaners.
2. Thera-Band® Exercise Balls are intended for indoor use only and are not designed for use outdoors.
3. Surface of use must be free from any objects that could puncture, tear, scuff, or otherwise damage your exercise ball.
4. Always inspect the exterior of the ball for damage (abrasion and scuffing, roundness, air leakage) before each use. Should any damage be evident discontinue use and replace with a new Thera-Band® Exercise Ball.
5. Thera-Band® Exercise Balls should not be exposed to extreme variations in temperature. Exposure to sources of heat such as heating ventilators, lamps and direct sunlight can negatively affect the integrity of the product increasing the possibility of failure.
6. Since the diameter of the exercise balls can vary due to environmental temperature fluctuations, the maximum diameter of the ball should be measured prior to use and adjustment made to comply with the correct diameter setting.
7. Thera-Band® Exercise Balls have been weight tested to support 600 lbs. of static (resting) weight.
Applying excessive force (eavy bouncing)or weight (dumbbells or barbells) may exceed the capacity of Thera-Band® Exercise Balls causeing breakage which could cause injury
Using Thera-Band® Exercise Balls in unusual exercises with a high load or level of difficulty, or used for purposes other than those for which they have been designed, or in ways inconsistent with any of these instructions will increase the possibility that your ball may fail and cause injury.