Sealing floor around hot water baseboard heater pipes

[Guest guest]

I am wanting to seal around the gaps around the pipes where they enter the floor

in my hot water baseboard heater. Because the pipes can reach 180 degrees,

should I use a high temperature caulk such as 3M's Fire Block sealant?

Since I am chemically sensitive, I am concerned about offgassing from the caulk.

Could it offgas quickly and be relatively safe in a short amount of time? Is

there another product that I could use? Would expanding foam work?

Thank you for any information and help!