Question. Are all types of pottery safe to cook in?
Answer. no
What step-by-step reasoning justifies that answer?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Reasoning: Some types of pottery glaze are unsafe for contact with food meant for human consumption. Antique pottery pieces may have hazardous levels of lead in them.