Which organization aims to promote public safety through scientific investigation of various materials in regard to the hazard present?

The organization that aims to promote public safety through the scientific investigation of various materials in regards to the hazards they present is Underwriters Laboratories (UL). This organization is well-known for its rigorous testing and certification processes that assess the safety, performance, and reliability of products used in various industries, including fire protection and emergency services.

UL conducts extensive research on materials and their behaviors under specific conditions, including fire exposure. By evaluating how these materials react to hazards such as heat and flames, UL provides critical information that helps manufacturers develop safer products and helps consumers make informed decisions. Their work ensures that products meet strict safety standards, thereby contributing to public safety.

Other organizations mentioned in the choices have different primary focuses. For instance, the Occupational Safety and Health Administration is concerned with ensuring safe working conditions and enforcing regulations, while the American Society for Testing and Materials focuses on developing standards for materials and products but does not specifically center on hazard investigation. The National Fire Protection Association is dedicated to fire prevention and safety codes rather than direct scientific analysis of materials. Therefore, Underwriters Laboratories stands out as the correct answer due to its specific mission and expertise in promoting safety through scientific inquiry into material hazards.