For at least several years I'be been storing various chloride solutions with methanol as a solute in Nalgene containers, which I believe are made from high density polyethylene (HDP).
But recently two of these containers had failed. On these containers the plastic seems to have hardened and cracked (see photographs below).
The other containers still seem to be pliable, in good shape. I thought that HDPE would be resilient to methanol and provide indefinite storage. Was I wrong? Or is it perhaps the methanol in combination with the particular salt that led to failure of the container? The failed containers had strontium and potassium chloride solution. Others like lithium, sodium and copper solutions are OK.