Using very high temperatures, you can convert hazardous waste into harmless chemicals such as CO and H2. However, this is not preferred because

The process of converting hazardous waste into harmless chemicals such as CO and H2 using very high temperatures is not preferred due to several reasons:

1. High Energy Consumption: The process requires a lot of energy to achieve the high temperatures needed for the conversion. This makes the process expensive and not energy efficient.

2. Potential for Harmful Emissions: While the end products are harmless, the process can potentially release harmful emissions. If not properly managed, these emissions can contribute to air pollution.

3. Difficulty in Waste Segregation: Not all hazardous waste can be treated this way. Some materials may not break down into harmless substances, or may produce other hazardous byproducts when subjected to high temperatures. This requires careful segregation of waste, which can be challenging.

4. Risk of Equipment Damage: The high temperatures required for this process can cause wear and tear on the equipment used, leading to high maintenance and replacement costs.

5. Regulatory Challenges: There may be strict regulations governing the disposal of hazardous waste and the emissions produced by this process. Complying with these regulations can be complex and costly.