This tool should be used as a guide only. Tankguard Storage may not be an exact match for Interline 850 by but we have given the closest match we can. Tankguard Storage should do the same job and have similar properties but you should always read the technical data sheets for both Tankguard Storage and Interline 850 to be sure. Please see any notes to see any major differences and call us on 01285 862132 if you have any specific questions.