In an emergency situation, the most important factor is to flush the eye of the irritant or foreign body as quickly as possible. This means that the most convenient source of water – often tap water – is usually the best choice.

However, if both are readily available, there are some considerations to take into account when deciding between tap water and distilled water for an eye wash:

Tap Water

Tap water is generally safe for eye washing. Its key advantage is that it is readily available in most locations, making it a practical choice in an emergency. However, tap water isn’t sterile and in some cases might contain chlorine or other additives, which could potentially cause discomfort, especially if the eye is already irritated.

Distilled Water

Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. This process removes impurities and minerals from the water. Distilled water is closer to being sterile than tap water, and it doesn’t contain chlorine or other additives. This makes it less likely to cause additional irritation when used for eye washing.

Sterile Saline Solution

In a non-emergency setting, or if available during an emergency, a sterile saline solution is often the best choice for eye washing. Saline solution has a salt concentration similar to human tears, making it comfortable to use. Sterile saline eye wash solutions are available in most pharmacies and are often included in first aid kits.

Conclusion

In an emergency situation, use the cleanest water available to you as quickly as possible. If you have a choice between tap water and distilled water, distilled water might cause less discomfort. However, the most important thing is to flush the eye immediately, not which type of water you use. After initial flushing, seek medical attention to ensure the irritant has been completely removed and there is no damage to the eye.