Disulfide is a pink liquid that comes in a small bottle. It also has a yellow label with the words "Danger! Explosive" written in red text on it.
Disulfide is a real-life compound that causes other items to explode when mixed together.
Role in episode
When SpongeBob and Mr. Krabs create a solution to clean the latter's money, SpongeBob accidentally puts two drops of disulfide into the mixture and an explosion blows himself and Mr. Krabs up.
Later, Plankton pours an entire bottle of disulfide into a vat after being tricked into thinking it is a part of the secret formula by Mr. Krabs. The explosion completely destroys the Chum Bucket, injures Plankton, and even nearly destroys Karen.