For how long is open coolant good for?

[moss]

I have a gallon jug of G-05 which is almost full, but was originally opened over two years ago and has been sitting in my car's trunk. Would it be okay to use? What is the time frame for opened coolant?
Thanks in advance

 

[HTSS_TR]

Yes, it is good to use.

 

[moss]

Thank you for the answer. I will go ahead and use it then.