[{"from": "human", "value": "Generate a molecule based on the given description. Solids containing varying amounts of formaldehyde, probably as paraformaldehyde (polymers of formula HO(CH2O)xH where x averages about 30). A hazard to the environment. Immediate steps should be taken to limit spread to the environment."}, {"from": "gpt", "value": "[C][=O]"}]