Carbon Monoxide

​What is CO?

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas produced by the ​incomplete combustion of carbon-containing fuels (e.g., gasoline, natural gas, coal, wood, propane). Common sources include:

• Vehicle exhaust
• Gas heaters, furnaces, or stoves
• Generators or grills used indoors
• Fireplaces or chimneys with poor ventilation
• Tobacco smoke

CO is highly toxic even at low concentrations because it ​binds to hemoglobin in red blood cells 200–240 times more effectively than oxygen, forming ​carboxyhemoglobin (COHb). This reduces oxygen delivery to tissues, leading to hypoxia (oxygen deprivation).

​Health Risks of CO Exposure

​1. Acute Poisoning (Short-Term Exposure)

Symptoms depend on CO concentration and exposure duration:

• ​Low levels (50–200 ppm):
  • Headache
  • Dizziness
  • Nausea
  • Fatigue (often mistaken for flu or food poisoning).
• ​Moderate levels (200–800 ppm):
  • Confusion
  • Chest pain
  • Shortness of breath
  • Impaired vision or coordination.
• ​High levels (>800 ppm):
  • Loss of consciousness
  • Seizures
  • Permanent organ damage (brain, heart)
  • ​Death within minutes at concentrations >1,200 ppm.

​2. Chronic Exposure (Long-Term Effects)

Prolonged low-level exposure (e.g., faulty heaters or occupational settings) can cause:

• Memory loss
• Depression
• Cardiovascular disease
• Neurological damage (e.g., Parkinsonism-like symptoms).

​3. Vulnerable Populations

• ​Pregnant women: CO crosses the placenta, risking fetal death or developmental issues.
• ​Infants, elderly, and those with heart/lung diseases: Higher susceptibility to severe effects.

​Why CO is Dangerous

• ​Undetectable without equipment: No warning smell, color, or taste.
• ​Rapid onset: Symptoms escalate quickly in enclosed spaces.
• ​Delayed effects: Neurological damage (e.g., memory loss) may appear weeks after exposure.

​Prevention and Safety

• ​Install CO detectors near sleeping areas and fuel-burning appliances.
• ​Never use generators, grills, or engines indoors (including garages).
• ​Ensure proper ventilation for heating systems, fireplaces, and stoves.
• ​Seek immediate fresh air and medical help if CO poisoning is suspected.

​Key Differences from CO2

While both are gases produced by combustion:

• ​CO is ​toxic at low levels (e.g., 50 ppm) and directly harms human health.
• ​CO2 is non-toxic at normal levels but poses risks at very high concentrations (>5,000 ppm).

CO is a ​silent killer, responsible for thousands of accidental deaths annually. Awareness, detectors, and proper ventilation are critical to prevention.