gas water heater in kitchen

I know gas water heaters should not be in bedrooms or bathrooms. But what about kitchens? To me it seems to be a possible CO2 problem. Anyone have any other thoughts?

Relatively common in townhomes and condos. . .

There are exceptions to the bedroom and bathroom installations can be located in a bathroom or bedroom if installed within an enclosed closet with self closing door with C air from an external source.

and older houses down this way. It seems it was extremely common in the subdivisions built here from right after World War II into the early 1960s.

We’ve got some 100 to 150 yr olds that have the boiler in the kit. not to mention hot water heater.