Plastic smell in my tank

[PeonyTealeaf]

Hello, I am setting up a tank and trying to regulate the temperature before putting the crabs in it. Last night I turned on the heat mat (which is attached to the back of the tank) and this morning I opened it to feel inside and there was a lingering plastic smell. There was some plastic aquarium plants near the back of the tank but they weren't pressed up tightly against the glass. There is also a plastic shower caddy suctioned to the opposite side of the tank. I'm not sure if this is normal or something I should be concerned about, I have since turned off the mat and have the lid off.
The temperature is set to 80 degrees with a humidity of 80%-85%. (There are no crabs in the tank.)

[KyMart]

Hello, I am setting up a tank and trying to regulate the temperature before putting the crabs in it. Last night I turned on the heat mat (which is attached to the back of the tank) and this morning I opened it to feel inside and there was a lingering plastic smell. There was some plastic aquarium plants near the back of the tank but they weren't pressed up tightly against the glass. There is also a plastic shower caddy suctioned to the opposite side of the tank. I'm not sure if this is normal or something I should be concerned about, I have since turned off the mat and have the lid off.
The temperature is set to 80 degrees with a humidity of 80%-85%. (There are no crabs in the tank.)

I have plastic plants by my heat mat in the back and haven't had any plastic smell at all! I also have a plastic container from Target as my second level that has one side up against the glass where the mat is as well, and haven't had any plastic smell from that either! That's so weird! Maybe it's just the new plastic item? Maybe it will go away? I'm not sure! Interested to see what other people say!