Problem 32 - Chemistry in Context

Question

A headline from the Pioneer Press in St. Paul, Minnesota (January 8,2008 ): "Man dies after exposure to gas; carbon monoxide sickens five others." a. Name two possible sources of \(\mathrm{CO}\) inside a home. b. The level measured was \(4700 \mathrm{ppm}\). Express this value as a percent. c. How does this level compare with the U.S. ambient air quality standards set by the EPA? d. Name three symptoms that the survivors most likely experienced. e. Where in a home should you install CO detectors? Note: Adjacent to a furnace is not usually recommended.

Step-by-Step Solution

Answer

a) Common sources are faulty gas appliances and fireplaces. b) 0.47%. c) 4700 ppm is much higher than EPA standards of 9 ppm. d) Likely symptoms include headaches, dizziness, and nausea. e) Place CO detectors near sleeping areas and combustion appliances, but not next to furnaces.

Step 1: Identifying CO sources

Common sources of carbon monoxide (1CO2) inside homes include malfunctioning gas appliances (like stoves or water heaters) and improperly ventilated fireplaces or wood stoves.

Step 2: Converting ppm to percent

To convert parts per million (ppm) to a percentage, divide by 10,000 because 1% is equivalent to 10,000 ppm. So, 4700 ppm can be converted to a percentage by calculating \( \frac{4700}{10000} = 0.47\% \).

Step 3: Comparing with EPA standards

The U.S. EPA sets the ambient air quality standard for CO at 9 ppm over 8 hours and 35 ppm over 1 hour at maximum. The measured level of 4700 ppm far exceeds these limits, indicating a dangerously high level of carbon monoxide in the air.

Step 4: Identifying symptoms of CO exposure

Carbon monoxide poisoning symptoms likely experienced by survivors include headaches, dizziness, and nausea. High levels can lead to more severe symptoms and even be life-threatening.

Step 5: Recommended placement for CO detectors

Carbon monoxide detectors should be placed near sleeping areas (to alert individuals during the night), on each level of a home, and near or around areas where combustion appliances are located, but not directly beside furnaces.

Key Concepts

CO Sources in Homes

Carbon monoxide (CO) is a colorless, odorless gas that can be highly dangerous when present in homes. It's crucial to recognize the sources of CO to protect yourself and your family. The most common sources of CO in homes are malfunctioning gas appliances such as stoves or water heaters. These appliances can leak CO if they are not properly maintained or ventilated.
Another significant source is improperly ventilated fireplaces or wood stoves. These can allow CO to accumulate since the burning of wood or other fuels releases the gas.

• Ensure all gas appliances are routinely checked by professionals.
• Properly ventilate spaces with fireplaces or wood stoves.
• Consider upgrading to appliances that have safety features to prevent CO leakage.

Recognizing these sources can help prevent the dangerous buildup of carbon monoxide.

CO Exposure Symptoms

Even a small amount of carbon monoxide in your home can be harmful due to its ability to disrupt your body's ability to use oxygen. Symptoms may appear as flu-like, making it difficult to identify without a proper detector.
Mild exposure can lead to headaches, dizziness, and nausea. These symptoms can appear rapidly and may soon be followed by vomiting and confusion if the exposure is not curtailed.
Severe exposure, particularly at levels seen in significant leaks, can lead to loss of consciousness or even death.

• Headaches and dizziness are early signs.
• Nausea and vomiting suggest worsening conditions.
• Confusion or passing out signal dangerous levels needing immediate intervention.

Always take such symptoms seriously, especially if others in the home exhibit similar signs.

CO Detector Placement

Strategically placing CO detectors in your home is crucial for safety. They serve as early warning systems in case of carbon monoxide leakage.
For optimal protection, CO detectors should be installed on each level of the home, especially near sleeping areas. This ensures that you're alerted during the night when you might not be aware of symptoms.

• Place near sleeping areas to wake occupants at alarming levels.
• Install on every level of your home.
• Avoid placing directly beside furnaces but nearby can be advantageous.

These practices ensure that exposure to CO can be minimized through timely detection.

EPA Air Quality Standards

The Environmental Protection Agency (EPA) in the United States sets strict guidelines to protect public health from harmful airborne pollutants, including carbon monoxide. Understanding these standards can help in recognizing unsafe conditions in your home.
The current EPA air quality standards for CO are set at 9 parts per million (ppm) over 8 hours, and 35 ppm over 1 hour. These limits are designed to prevent the adverse health effects of CO exposure.
A CO level of 4700 ppm, as noted in the exercise, is astronomically higher than these limits, highlighting the significant danger posed by CO accumulation.

• 9 ppm over 8 hours is the long-term safety limit.
• 35 ppm over 1 hour is the short-term safety limit.
• 4700 ppm poses immediate and severe health risks.

Being informed of the EPA standards helps in assessing the risk level and taking timely action.