How to Prepare 8% Sodium Chloride Solution
To make 8% normal saline, dissolve 80 grams of sodium chloride (NaCl) in water and bring the total volume to 1000 mL (1 liter). This creates a solution containing 80 grams of NaCl per 100 mL of final solution.
Calculation Method
For 1 liter (1000 mL): Add 80 grams of NaCl to approximately 900 mL of water, then add water to reach exactly 1000 mL total volume 1
For smaller volumes: Use the formula: grams of NaCl needed = (desired volume in mL × 8) ÷ 100
- Example: For 500 mL of 8% saline = (500 × 8) ÷ 100 = 40 grams NaCl 1
For 100 mL: Dissolve 8 grams of NaCl in water to a final volume of 100 mL 1
Preparation Steps
Measure the sodium chloride powder using a calibrated scale (80 grams for 1 liter) 1
Add NaCl to approximately 80-90% of the final desired water volume first, then dissolve completely 1
Bring to final volume by adding water until you reach the exact target volume (e.g., 1000 mL) 1
Mix thoroughly until all crystals are completely dissolved 1
Important Considerations for Hydrated Compounds
If using hydrated sodium chloride (NaCl·xH₂O), you must account for the water molecules attached to the compound by using the formula weight listed on the bottle rather than the molecular weight of pure NaCl 1
The attached water molecules contribute to the solution volume and must be factored into your calculations to avoid diluting the final concentration 1
Clinical Context Warning
8% sodium chloride is a highly concentrated hypertonic solution that should never be used for routine fluid resuscitation. Standard clinical concentrations are 0.9% (normal saline), 3% (hypertonic saline for specific indications like increased intracranial pressure), or balanced crystalloid solutions 2, 3. Solutions above 3% concentration carry significant risks including hemolysis when administered peripherally 4. Any use of such concentrated solutions requires specific clinical indication, careful administration protocols, and appropriate monitoring.