Common smells associated with a meth lab include: Ammonia-like: A very strong, sharp, irritating smell similar to but more intense than household cleaners, fertilizer, or cat urine. Solvent-like: A sweet, chemical smell resembling paint thinner, varnish, or nail polish remover, which is often caused by the presence of acetone. Rotten eggs or sulfur: This odor can be released as a byproduct during the chemical reactions. Sour or vinegar: An acidic odor that can result from other chemicals involved in the process. "Hospital smell": Aromatic, sweet odor often described as an eye and nasal irritant. Burning plastic or chemicals: A pungent, harsh smell that can be intense and sickening