You Can't Smell It, But It Kills

The US Consumer Products Safety Commission estimates that between 8,000 to 15,000 people are examined or treated in hospitals for non-fire related CO poisoning each year.

The smartest way to confirm there are no dangerous levels of CO gasses in your home is to have a complete home CO check by a certified contractor. During the process your contractor should check every combustible appliance using a properly calibrated Carbon Monoxide Analyzer. Your contractor should also be checking for correct chimney draft on your fireplace, furnace and hot water heater.

Low concentrations of CO breathed over long periods of time may contribute to other illnesses.

First level (that is, most - Way Cool) U. L. approved Carbon Monoxide (CO) alarms are made to go off at 70 parts per million (ppm). (these are the type sold at home centers- JH) However, lower levels of CO can be harmful.

Low-level Exposure (less than 35 ppm): of carbon monoxide poisoning can be confused with flu-like symptoms, food poisoning, or other illnesses and can have significant long-term health risks if left untreated.

High-level Exposure (more than 35 ppm; less than 70 ppm): Severe throbbing headache, drowsiness, confusion, fast heart rate.

Crisis-level Exposure (more than 70 ppm): Unconsciousness, convulsions, cardio respiratory failure, death.

9 ppm - Maximum allowable CO in living space for 8 hours per the American Society of Heating, Refrigeration & Air Conditioning Engineers (ASHRAE)

9 ppm - Maximum allowable outdoor 8 hours per the Environmental Protection Agency (EPA)

15-30 ppm - First level reported to cause harmful affects per the World Health Organization (WHO)

30 ppm - Earliest onset of exercise induced angina (WHO)

50 ppm - The maximum allowable concentration for continuous exposure for healthy adults in any 8 hour period, as recommended by the Occupation and Safety and Health Administration (OSHA) ina work environment.

(As you can see, the most common types do not protect - alarm at these levels. - Way Cool)

70 ppm - First level U. L. approved alarms must go off 2-4 hours.

200 ppm - Slight headache, fatigue, dizziness, nausea after 2-3 hours.

400 ppm - Frontal headaches within 1-2- hours, life threatening after 3 hours.

800 ppm - Dizziness, nausea, and convulsions within 45 minutes. Unconsciousness within 2 hours. Death within 2-3 hours.

These symptoms are typical for healthy adults. The critical or chronically ill, pregnant women, infants and others with respiratory difficulties can be impacted earlier and experience more adverse effects.

The excerpt above comes from Page 4 of the NSI 3000 Low-Level CO Monitor Owner's Manual.