“chemical • Affected • Always • Between • Chemical • Chemicals • Common • Completely • Concentration • Concentrations • Contain • Contains • Cost • Dangerous • Easier • Effects • Everyday • Expensive • Find • Found • Free” • Free • From • Harmful • Health • Human • Humans • Industries • Ingested • Kind • Laboratory • Made • Manufacturing • Mean • Means • More • Natural • Negative • Never • Oxygen • Prefer • Process • Product • Safer • Safety • Substances • Synthetic • There • They • While