Is sea salt safe for wounds?

Because of its availability, serious wouds and operating fields are often flushed with Normal Saline, which is 0.9% w/v of NaCl, about 300 mOsm/L (cit. WikiPedia: Saline). This is close to the blood's normal salinity. Note that this is used clinically to clean and disinfect wounds. The body does the healing.