Smart Tag for Food (IMAGE) American Chemical Society Caption The green smart tag on the bottle above indicates that the product is no longer fresh. The image is a screenshot of a video: http://www.youtube.com/watch?v=y-Fpj9bdht4. Credit Chao Zhang, Ph.D. Usage Restrictions Please credit Chao Zhang, Ph.D. , and the American Chemical Society. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.