Which organization is known for providing testing and certification for firestop products?

Underwriters Laboratories (UL) is well-known for its rigorous testing and certification of firestop products. This organization focuses on establishing safety standards and conducting evaluations to ensure that products meet specific performance criteria in terms of fire resistance and safety. UL's certification helps manufacturers, builders, and consumers have confidence in the firestop products they are using, ensuring these products will perform as intended in a fire scenario.

The other organizations listed have different focuses: The National Fire Protection Association (NFPA) is primarily involved in developing codes and standards related to fire safety, but it does not conduct testing; the Occupational Safety and Health Administration (OSHA) is concerned with workplace safety regulations and does not certify products; and the American National Standards Institute (ANSI) oversees the development of standards for various industries but is not specifically a testing lab for products. Thus, the role of UL in testing and certifying firestop products is critical and distinct within the context of fire safety.