Construction Health and Safety Technician (CHST) 2025 – 400 Free Practice Questions to Pass the Exam

The identification of carbon monoxide as a blood toxin relates to its ability to bind with hemoglobin in the blood, forming carboxyhemoglobin. This binding significantly reduces the blood's capacity to carry oxygen, leading to conditions of hypoxia, where the body's tissues are deprived of adequate oxygen supply. Hypoxia can result in serious health issues, including organ dysfunction and, in severe cases, death.

Methylene chloride and mercury can pose significant health risks, but their primary mechanisms of toxicity differ. Methylene chloride does not directly interfere with oxygen transport like carbon monoxide does, and while mercury is toxic, it primarily affects the nervous system rather than directly inducing hypoxic conditions in the way carbon monoxide does. Carbon dioxide, while an important component of respiration and capable of inducing asphyxia in high concentrations, functions differently as it primarily results in an excess of carbon dioxide rather than competing with oxygen transport in the blood. This underscores why carbon monoxide is specifically recognized for creating hypoxia in the presence of its toxicity.