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The test is designed to determine the ability of a substance to undergo oxidative self-heating or autoignition by exposing it to air at elevated temperatures in a wire mesh cube. The Grewer Self-Heating Test is a laboratory procedure designed to evaluate the self-heating tendencies of certain solid or liquid materials. Specifically, it assesses a substance’s potential for spontaneous ignition or combustion when exposed to elevated temperatures. During the Grewer test, a sample of the material is placed inside a wire mesh cube that is then immersed in a temperature-controlled Grewer furnace. The temperature of the furnace gradually increases at a predetermined rate while the sample’s temperature is continuously monitored.


The sample basket is filled to the top with the test material and tapped several times. The thermocouple is placed at the center of the sample basket.

In the temperature ramp test, the oven is not pre-heated before test begins, however, in the isothermal test, the oven is pre-heated to the desired temperature before the sample is placed at its desired position for the test to begin. It is ensured that the flow of air into the oven is controlled at a rate of 1 or 2 liters per minute and the temperature rise does not exceed 2ᣞC per minute. The graph is then monitored for self-heating or autoignition behaviors for up to 12 hours. It is recommended to test the sample with 95% minus 200 mesh, however, under certain circumstances the sample may be tested in its commercial form. In case of uncertainty on how to perform the testing please contact Prime Process Safety Center for guidance.

Applicable Standard

The Grewer Oven Self-Heating test is conducted in accordance with VDI 2263, Autoignition Testing as per Grewer.


Data interpretation

A substance is classified as self-heating when the curve of the sample crosses the curve of the inert reference standard but does not reach 400ᣞC while autoignition occurs when the temperature of the sample reaches 400ᣞC or more. The test measures the sample’s ability to generate heat and its corresponding temperature rise under controlled conditions. This is crucial in determining if the material exhibits self-heating properties that could lead to spontaneous combustion or ignition. The Grewer Self-Heating Test is commonly applied to various substances, such as certain chemicals, pharmaceutical powders, combustible dust materials or other potentially hazardous materials. It helps in assessing the risk of spontaneous combustion during storage, transportation, or processing of these substances.

When to perform Grewer Oven Self -Heating Test

The Grewer Oven is a great tool for determining the onset self-heating temperature of combustible powders. It provides the screening method for autoignition temperature determination. This test is designed to determine the relative self-heating onset temperature of a material in a hot air-stream. It is applied to products which are subjected to elevated temperatures in an air stream.

Why work with Prime Process Safety Center

  • Prime Process Safety Center is a leader in process safety testing with very experienced laboratory personnel. At Prime Process Safety Center our goal is to provide accurate, reliable and defensible data that meets industry and regulatory standards. We understand the need for the quality of your data, and we work assiduously to achieve just that.
  • We are knowledgeable and experienced in performing Grewer Self-Heating Tests, ensuring accurate and reliable results.
  • We have state-of-the-art Grewer Self-heating testing equipment, providing precise and sensitive measurements.
  • We follow strict testing protocols and quality control measures to ensure consistent and reliable test results.
  • Our team can interpret and analyze the data obtained from the tests, providing valuable insights and recommendations for your specific application or research.


What is the Grewer Self-Heating Test?

Answer: The Grewer Self-Heating Test is a laboratory procedure used to assess the propensity of materials to self-heat and potentially undergo spontaneous ignition or combustion when exposed to elevated temperatures.

How does the Grewer Self-Heating Test work?

Answer: During the test, a sample of the material is placed in a vessel immersed in a temperature-controlled furnace. The sample’s temperature rise is monitored as the temperature of the furnace gradually increases.

Why is the Grewer Self-Heating Test conducted?

Answer: The test is performed to evaluate a material’s self-heating properties, particularly its tendency to generate heat and potentially ignite without an external heat source.

What parameters are monitored during the Grewer Self-Heating Test?

Answer: The test monitors the sample’s temperature changes over time when subjected to increasing temperatures, observing any self-heating tendencies.

How long does the Grewer Self-Heating Test typically last?

Answer: The duration can vary based on the material being tested and the specified testing conditions, ranging from several hours to multiple days but typically we conduct this test for up to 12 hours.

What safety measures are observed during the Grewer Self-Heating Test?

Answer: Safety protocols are followed to prevent potential fire hazards. Adequate ventilation and proper handling of materials susceptible to spontaneous heating are crucial.

What does a positive result in the Grewer Self-Heating Test indicate?

Answer: A positive result suggests that the material has exhibited self-heating tendencies, indicating a potential risk of spontaneous ignition or combustion.

How is the data from the Grewer Self-Heating Test utilized in industries?

Answer: Industries use test results to assess fire risks associated with materials, develop preventive measures, and establish safe storage, handling, and transportation practices.

Is the Grewer Self-Heating Test a standardized method?

Answer: Yes, the Grewer Self-Heating Test is a recognized method used in various industries to evaluate materials’ self-heating tendencies and assess potential fire hazards.