EDTA is safe when used as a prescription medicine, as eye drops, and in small amounts as a preservative in foods. EDTA can cause abdominal cramps, nausea, vomiting, diarrhea, headache, low blood pressure, skin problems, and fever. It is UNSAFE to use more than 3 grams of EDTA per day, or to take it longer than 5 to 7 days.Is EDTA a strong acid?
The structure of EDTA is shown below. However, there are a few organic acids that are quite strong. Trifluoroacetic acid has an approximate pKa of -0.3 (approximate because water levels pKas and the best you can do is between 0–14). Methane sulfonic acid is even stronger coming in at an estimated pKa of -2.6.