The threshold limit value of CO in the air is nearly ____whereas that of `CO_2` is nearly _________

Answer

To solve the question regarding the threshold limit values of CO (carbon monoxide) and CO2 (carbon dioxide) in the air, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Threshold Limit Value (TLV)**:
- The threshold limit value is the maximum concentration of a substance in the air that is considered safe for human exposure over a specified period.

2. **Identify the TLV for CO**:
- The threshold limit value for carbon monoxide (CO) in the air is approximately **40 parts per million (ppm)**. This means that at concentrations above this level, CO can be harmful to human health.

3. **Identify the TLV for CO2**:
- The threshold limit value for carbon dioxide (CO2) in the air is approximately **5000 parts per million (ppm)**. This indicates that CO2 can be harmful to humans if its concentration exceeds this level.

4. **Summarize the Findings**:
- Therefore, the answer to the question is:
- The threshold limit value of CO in the air is nearly **40 ppm**, whereas that of CO2 is nearly **5000 ppm**.

### Final Answer:
The threshold limit value of CO in the air is nearly **40 ppm**, whereas that of CO2 is nearly **5000 ppm**.

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