Sodium Chloride 0.9% — EU research guide.

What is Sodium Chloride 0.9%?

Sodium chloride 0.9% w/v is a sterile solution of 9 g/L NaCl in water for injection, with about 154 mmol/L each of sodium and chloride and an osmolarity of about 308 mOsm/L, close to blood plasma. It is a fluid and electrolyte solution and a common dissolvent and carrier for injectable drugs. As a diluent it has no drug mechanism: it dissolves or dilutes another substance. The main practical distinction is between preservative-free saline, which is single-use, and bacteriostatic saline, which contains 0.9% benzyl alcohol and is supplied in multiple-dose vials.

What does the research show?

No efficacy claims are made: as a diluent it is a vehicle, not a treatment. A B. Braun product label describes 0.9% sodium chloride injection as a dissolvent and carrier solution for injectable drugs, and a US label states that it contains no bacteriostat and is single-dose. A critical care review (Reddy 2016) states that 0.9% saline is not physiologically normal: it has more chloride than plasma and a strong ion difference of zero, and large volumes can cause hyperchloraemic metabolic acidosis. A history review (Awad 2008) argues that the 0.9% figure has no firm scientific or historical basis and stems mainly from early laboratory work on red blood cells. On vial types, CDC guidance says a single-dose vial is approved for one patient and one case only, and that an opened multi-dose vial should be dated and discarded within 28 days unless the manufacturer states another date.

EU legal status

Authorised medicinal products exist in the EU, authorised nationally; an example is B. Braun Isotone Natriumchloridloesung 0,9 % Injektionsloesung in Germany (marketing authorisation number 6697366.00.00, holder B. Braun Melsungen AG), labelled as a carrier solution for compatible electrolyte concentrates and medicines, to be used immediately after opening with the container and remaining solution discarded after use. A vial sold by a research vendor is not itself an authorised medicine unless it carries a marketing authorisation number; the sterility, grade, preservative content, labelling and Ph. Eur. or USP compliance of a specific vendor vial cannot be assumed from this page. As a substance it is not listed by WADA (the 2026 List was read via a national anti-doping agency copy, as the WADA PDF was blocked), but Prohibited Method M2 covers intravenous infusions or injections of more than 100 mL per 12 hours, except those legitimately received in hospital treatment, surgery or clinical diagnostic investigations.