Naphthalene cannot exceed what maximum concentration?

In the context of heating oil and its components, Naphthalene is a substance of concern due to its potential health and environmental effects. Regulations often set specific limits on the concentration of certain compounds in heating oil to ensure safety for both human health and the environment. The correct answer, which indicates that Naphthalene cannot exceed a maximum concentration of 6.5 parts per million (ppm), is based on these regulatory standards that aim to minimize exposure risks.

Exceeding this limit could pose risks of health effects such as respiratory issues when inhaled or skin irritation. Additionally, high concentrations can lead to environmental impacts if the heating oil is spilled or leaks into the soil or waterways. Therefore, maintaining Naphthalene concentrations at or below this specified level is essential for compliance with safety regulations and to protect both users and the environment.

Overall, the correct concentration threshold reflects a balance between practical usability of heating oil and safeguarding public health and the environment.