Boron (B) is an important element which should be considered seriously for drinking water production. Boron removal from seawater using nanofiltration (NF) and reverse osmosis (RO) membranes was investigated. Increase in salt concentration effects boron removal positively when RO membranes and negatively when NF membranes were used. Time dependencies of membrane processes for boron removal were also investigated. Based on the boron concentration in seawater and treated seawater, toxicity tests were conducted using Western Blotting method. HEK 293, human embryonic kidney cell line and antibodies, Bcl-2 and β-actin were used for boron toxicity tests.