Final answer:
The primary difference between HMIS and NFPA lies in their target audience with HMIS intended for workplace safety and NFPA designed for emergency responders. The NFPA uses a hazard diamond to quickly communicate the severity of fire, health, reactivity, and special hazards associated with a chemical substance.
Step-by-step explanation:
The largest area of difference between the Hazardous Materials Identification System (HMIS) and the National Fire Protection Agency (NFPA) 704 Hazard Identification System revolves around their intended audience and how the hazard information is conveyed. While both systems are designed to provide safety information regarding hazardous substances, the HMIS is primarily meant for workers who handle these substances on a daily basis, focusing on workplace safety. On the other hand, the NFPA system, with its recognizable NFPA hazard diamond, is geared towards emergency responders such as firefighters and emergency medical services (EMS). Furthermore, the NFPA diamond provides a quick assessment of the substance's immediate hazards in case of an emergency situation, with the red, blue, yellow, and white diamonds representing fire hazard, health hazard, reactivity, and other special hazards respectively. Each of these hazards is rated on a scale from 0 to 4, with 0 indicating no hazard and 4 indicating extreme danger.