Assertion: carbon monoxide | /r/HasProperty | encountered in concentration
Facets:
value: above about 35 ppm
type: OTHER
Source sentences:
text: It is toxic to animals that use hemoglobin as an oxygen carrier (both invertebrate and vertebrate) when encountered in concentrations above about 35 ppm, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions.