As far as i know, only etherdelta is the most safest of all exchange, but i suggest you to save and put your money in a wallet so that it will be kept because you cannot rely on any exchange in keeping your coins.
I doubt that etherdelta, is the most safest of all exchange. Instead, etherdelta is the most dangerous decentralized platform exchange compare to other platform. Because giving or importing your private key to this platform is the most dangerous things for the traders if you are going to use this one which is etherdelta. Besides, Etherdelta has already a bad record before in terms of the issues of hacking the account of the wallet of their users. So, for me I think binance is safe as long as you activate your 2FA and pass the KYC too.