According to testimonies of other people, this KINGBO product it is best staying refrigerated when is not in frequent use.
It is best to keep a portion in a syringe so to serve you in small jobs.
KINGBO RMA-218 which exposed to heat due hot climate or hot working environment started getting a dark yellowish color after several months, even in this condition it is chemically good for use, but it texture changes slightly and makes it harder to fill the syringe with it.
I am keeping my constantly refrigerated, therefore its safe.