Certified Fire Protection Specialist (CFPS) Practice

Arsine is highly toxic and poses significant health risks to individuals exposed to it, making it the correct choice in this context. It is a colorless gas with a characteristic garlic-like odor and can be lethal even at very low concentrations. When inhaled, arsine can lead to severe health issues, including hemolytic anemia and damage to the respiratory system, as it can disrupt the function of red blood cells.

While hydrogen, acrylic acid, and chlorine are hazardous substances, they are not classified as highly toxic in comparison to arsine. Hydrogen, for example, is primarily flammable and poses explosive risks, but it is not toxic at lower concentrations. Acrylic acid is an irritant and can cause harm through skin and respiratory exposure, but its level of toxicity does not reach that of arsine. Chlorine, another hazardous gas, is a strong irritant capable of causing respiratory distress, yet its acute toxicity does not match that of arsine. Therefore, in the context of semiconductor processes, arsine is recognized as the highly toxic gas among the options provided.