"Sugar rockets" or sparklers made of metal fillings, potassium nitrate and some carbon compound are easily made, and there is a lot of tutorials and videos on the internet suggesting them as relatively safe and non toxic DIY fireworks.
However reading on the potassium nitrate reaction, it decomposes to potassium nitrite when heated. This compound is toxic, and is suspected to be mutagenic as well. It is also an oxidizer on its own.
So I have safety concerns and questions:
- Do the charred remains of potassium nitrate fire experiments need to be handled as toxic waste?
- If potassium nitrite is an oxidizer, what does it decompose to when burned along with a carbon compound?