What are you using the stock solution for? Ethanol is a common solvent used to dissolve salicylic acid. This paper identified solubilities in different solvents
Article Solubility and Melting Properties of Salicylic Acid
, following citations might help answer your question too. Good luck!
In aqueous solution, salicylic acid should be quite stable to heating. However, the solubility in water at room temperature is rather low (ca. 2 g per liter). As Cory Jensen mentioned, the solubility in ethanol at room temperature is much higher (ca. 500 g per liter). Decomposition of salicylic acid will only occur upon heating of the solid material. When heated, solid salicylic acid decomposes to give CO2 and phenol.
Rakesh Bhaskar, I used salicylic acid with some ethanol controls in a study with some ability to monitor for reactive specie generation upon root elicitation,
Article Methyl jasmonate improves radical generation in macrophyte p...
I found my subject to be sensitive to salicylic acid as part of the study and concluded that some more elaborate molecular methods should be applied. I don't know the details of your study but recommend working with the natural or culture conditions (solutions) related to your application and control for any solvent you would use.