 Residues of phosphamidon in the plant , soil and water were analysed by GLC , at various time intervals , and were found to decrease steadily up to 00 days . A second application of the pesticide was made on day 000 and grains harvested on day 000 . The residue level in the plants was 0 . 00 microg g ( -0 ) and in the grains 0 . 00 microg g ( -0 ) with the high dose . This is slightly below the EPA prescribed tolerance level of 0 . 00 microg g ( -0 ) . 