Is EDTA Necessary with Distilled Water?

Based on the properties of the ingredients, using purified or distilled water, such as Purified Water (TDS Limit 1PPM), means the water is already very pure with minimal dissolved solids and ions.

EDTA, like Disodium EDTA or Tetrasodium EDTA, primarily functions as a chelating agent. This means it binds to metal ions that might be present in less pure water sources (like tap water or even some bottled water) to prevent them from interfering with other ingredients in your formulation or causing instability.

Since distilled water is already free of these interfering ions, adding EDTA is generally not strictly necessary for its primary chelating purpose.

However, adding a small amount of EDTA to a formulation, even one using distilled water, is typically not harmful and can sometimes offer additional benefits in terms of overall formula stability and preservation efficacy by complexing trace metal ions that might be introduced from other ingredients or packaging. This aligns with the staff's response that it's not necessary but doesn't cause harm.

In summary, while not essential when using high-purity distilled water, including EDTA is acceptable and may offer minor stability advantages.