To be honest they were judged against much lower criteria in those days, not saying that its a good idea to use it preharvest,but what about lots of drugs we take most are harmful if not used correctly, even salt which we must have to live will kill us with a overdose, its dose not chemical that kills. The trouble is these days the truth is a very rare commodity too many vested interests in everything, whether thats brexit, chemicals or global warmingWell there you go. In their days, ddt was safe, aldrin was safe, benlate was safe, op sheep dip, not only safe but compulsory so just crack on then and hope the nhs gets its act together