What is the ASTM standard for the lightweight sweater flammability test?

As of my knowledge cutoff in September 2021, there is no specific ASTM standard that addresses the flammability of lightweight sweaters. However, ASTM International has developed various standards related to textile flammability testing that may be applicable to lightweight sweaters. These standards are part of the ASTM D13 Committee on Textiles.

The most commonly referenced standard for textile flammability testing is ASTM D6413, titled "Standard Test Method for Flame Resistance of Textiles (Vertical Test)." This test method determines the flame resistance of fabrics when subjected to a small ignition source under controlled laboratory conditions.

While ASTM D6413 is not specific to lightweight sweaters, it can be used as a general guideline to evaluate the flammability characteristics of textile materials, including lightweight sweaters. It involves exposing a vertically oriented fabric specimen to a defined flame source and measuring various parameters such as afterflame time, afterglow time, and char length.

It's worth noting that standards can evolve and new ones can be introduced over time. Therefore, it's advisable to consult the latest version of ASTM standards or reach out to ASTM International for the most up-to-date information on flammability testing for lightweight sweaters.