TVA Best Practices

Procedures to Keep Vermiculite Asbestos Free


Vermiculite is one of the world’s most versatile minerals, and, like other minerals, is safe when used according to the supplier’s recommendations. Asbestiform minerals have been identified as potential trace components in vermiculite ore. Asbestos is a term applied to a group of silicate minerals belonging to the serpentine and amphibole groups which have crystallized in the asbestiform habit, causing them to be easily separated into long, thin, flexible, strong fibers when crushed or processed.

Recognizing the potential for contamination between vermiculite and asbestos, The Vermiculite Association created the Best Practices Program for Asbestos Detection and Control Protocol, promoting mining operations that follow proper protocol for asbestos detection and control. Only two companies in the United States and four total worldwide participate in this program, and Specialty Vermiculite—part of Dicalite Management Group—is one of them.

TVA Best Practices

The TVA Best Practices program requires participants to follow specific protocols related to many areas of internal controls. It examines quality control systems, management, technical training, asbestos control procedures, analytical test procedures, microscope setup, and pre-shipment quality assurance.

Training Required

Management and technicians must have knowledge and training about all aspects of the Quality systems, including:

  • mine geology
  • mineralogy
  • sampling
  • analysis
  • health and safety

Asbestos Control Procedures

TVA Best Practices requires vermiculite to be tested at different stages for due diligence. One of the key parts of this is documentation, ensuring all vermiculite can be traced from pre-extraction to the customers.

Pre-Extraction: Prior to any mining, a mineralogical evaluation is required to test for any suspected asbestos minerals. All tests must be carried out by trained and qualified technicians or an accredited commercial laboratory.

Processed Vermiculite: TVA requires a minimum of one daily composite sample of approximately 1kg/hour to be delivered to an internal laboratory for analysis. Different grades of vermiculite have different particle sizes, so sample size may vary per grade.

Analytical Test Procedures

These procedures determine the percent by weight of asbestiform minerals in a vermiculite ore or concentrate sample. The method is expected to be able to identify any asbestos types accurately measure 0.10% weight asbestos in a representative sample.

Part of the TVA Best Practices program includes specific microscope techniques to ensure accurate testing. A stereo-binocular microscopy inspection is completed in a lab. Under a microscope, a 50g vermiculite sample is examined at magnifications between 10X and 40X, looking to identify any suspect fibrous minerals. Any suspicious materials found are then individually inspected and weighed for identification.

Safety Is Our Top Priority.

Not all vermiculite contains asbestos, but due diligence is still required to ensure the safety of the vermiculite we supply. That’s why we participate in the Best Practices program. If you’d like to learn more about our processes, products, and receive a free sample of vermiculite, call us today at 866-728-3303.

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