Cal 133 Testing

Micom Laboratories offers Cal 133 testing. Cal 133 – Flammability Test Procedure for Seating Furniture for Use In Public Occupancies – was adopted in 1992 by the State of California for all seating furniture in public occupancies where buildings are not sprinklered. Furniture flammability testing to this method is required in many states for seating products used in hotels, motels, correctional services, health care and educational establishments. For a list of States/Jurisdictions requiring this type of testing please see: California Technical Bulletin 133.

 Cal 133 and ASTM E-1537 are test protocols that are very similar and use the same heat source, they are quite different from CAL TB-117, NFPA 260 and the UFAC standard who all use a smoldering cigarette as a heat source.

 With the Exception of furnishings for commercial aircrafts, this standard is one of the most severe flammability test that exists for seating products.

When designing a chair so that it meets this standard, manufacturers often have to use fire retardant barriers in their upholstering process. These barriers are often made of Kevlar or fiberglass. Surface treatment is also used for the same purpose.

 Use and factors to be considered:

There are two test methods in Cal 133: method A & B. Both test methods use the same ignition source and the exposure time to that ignition source is 80 seconds. The difference between the two test methods is the measured parameters to establish product compliance. For method A the pass/fail criteria are:

  1. A temperature increase of 200°F or greater at the ceiling thermocouple.
  2. A temperature increase of 50°F or greater at the 4-foot thermocouple.
  3. Greater than 75% opacity at the 4-foot smoke opacity monitor.
  4. Carbon monoxide concentration in the room, as measured in accordance with Section VI, Part C, of 1000 ppm or greater for 5 minutes.
  5. Weight loss due to combustion of 3 pounds or greater in the first 10 minutes of the test.

For method B the pass/fail criteria are:

  1. A maximum rate of heat release of 80 kW or greater.
  2. A total heat release of 25 MJ or greater in the first 10 minutes of the test.
  3. Greater than 75% opacity at the 4-foot smoke opacity monitor.
  4. The carbon monoxide concentration in the room, as measured in accordance with Section VI, Part C, of 1000 ppm or greater for 5 minutes.

Manufacturers can decide to test to either method A, method B or to both.

When requiring testing to this standard, manufacturers should also consider the use of the Cal 133 Code of Practice published by the State of California to improve repeatability. Finally, to address the fact that this standard lacks guidance on the applicability of test results to other similar products produced by a manufacturer; BIFMA published guidelines as to how to select samples and what should be the parameters justifying a re-test. This document should be considered as well.

Typical Experimental parameters:

Number of specimens/product: 1 specimen
Method: A, B or both
Specimen to be tested: Please review BIFMA Guidelines
Conditioning Temperature: 70±5°F
Conditioning and testing relative humidity: less than 55%

Other related test methods:

For additional information related to Cal 133; please see California Technical Bulletin 133 and BIFMA X5.1, BIFMA X5.4, BIFMA X5.11.

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