CO in indoor ice rinks: Evaluation of absorption by adult hockey players

“We suggest that an average environmental concentration of 20 ppm of CO for the duration of a hockey game (90 minutes) should be reference limit not to be exceeded in indoor skating rinks.”

Carbon monoxide in indoor ice skating rinks: Evaluation of absorption by adult hockey players (Journal Article) | OSTI.GOV

Carbon monoxide in indoor ice skating rinks: evaluation of absorption by adult hockey players – PubMed (nih.gov)