Low Temperature Brittleness Apparatus is designed for plastics and elastomers of flexible and coated fabrics. It provides for the evaluation of the long term effects, such as crystallization or the incompatibility of plasticizers at low temperature in the materials being tested. The test establishes the temperature known as the Brittleness Temperature at which no cracks or failures are experienced when the test samples are subject to known impact energy. The samples are submerged in a bath containing methal, silicon fluid or similar to produce sub-zero temperatures.