Which organization is the largest non-governmental testing agency setting standards in textiles?

The correct answer is ASTM. The American Society for Testing and Materials (ASTM) is a recognized leader in developing and publishing voluntary consensus technical standards for a wide variety of materials, products, systems, and services, including textiles. ASTM standards are widely used in the industry to ensure quality, safety, and performance specifications. This organization operates without government direction, allowing for extensive participation from diverse stakeholders, including manufacturers, consumers, and researchers.

By setting measurable criteria for the textile industry, ASTM helps ensure that products meet established performance and safety standards, which is essential for maintaining quality and consumer trust in textile products. This ability to provide rigorous standards makes ASTM a crucial entity in the textiles sector and a primary source for testing procedures and material specifications.

The other options, while involved in various spheres, do not have the same predominant role in setting textile standards.