Yes, saline does expire. Physiological sodium chloride solution normally has a shelf life of 24 months. Deterioration and bacterial growth will usually occur if it exceeds the validity period. In addition, the water inside can evaporate over a long time, increasing the salt concentration in the solution. It cannot be used at this time to avoid skin and mucous membranes irritation, causing allergies or other adverse reactions[1].

Saline solution, also called normal saline solution, is a pH-balanced mixture of water and salt (sodium chloride). The saline solution contains 0.9% salt. And fun fact: That closely resembles the concentration of salt found in our blood and tears. Saline is often used in the medical field to clean wounds, clear out sinuses, and treat dehydration. However, it can also be important for your eyes and contact lenses.

Intravenous sodium chloride solutions are routinely used in the hospital to treat various medical conditions. Some conditions that may warrant the use of intravenous sodium chloride solutions include hypovolemic shock, dehydration, malignant hyperthermia, diabetic ketoacidosis, and hyponatremia. Emergency medical technicians also transport intravenous sodium chloride solutions to treat hypothermia and hyperthermia. Recent guidelines for cardiopulmonary resuscitation recommend the use of cold intravenous sodium chloride solution in the treatment of cardiac arrest. Treatment is carried out by infusing a cooled sodium chloride solution. Similarly, patients presenting with hypothermia may be treated with an infusion of warmed sodium chloride solution. In some cases, patients may be given warmed fluids to reduce perioperative hypothermiap[2].

References

[1] https://www. steroplast.co.uk/knowledge-base/what-is-saline-wound-wash. html#:~:text= Saline%20wound%20wash%20stays%20sterile, years %20in%20our%2020ml%20pods.

[2] Enrique Puertos, PharmD. “Extended Stability of Intravenous 0.9% Sodium Chloride Solution After Prolonged Heating or Cooling.”Hospital Pharmacy 49 3(2014): 269–272.