GTP cannot advise whether or not to use fuel. If it is different than what you are used to seeing, you must investigate further. Contact the fuel supplier and ask them if their fuel has changed. Compare your results with their test results. If the fuel you received is different from what they sent to you, isolate the fuel and do not use it until it is cleared by your supplier as safe. A common cause of contamination is accidental mixing of fuels at the terminal or in the delivery truck or pipeline.