1 In general, the total dissolved solids concentration is the sum of the cations (positively charged) and anions (negatively charged) ions in the water.  Parts per Million (ppm) is the weight-to-weight ratio of any ion to water.
If you refrigerate the rice, and you want to eat it cold, its perfectly fine. People eat cold rice salads all the time. Cold rice pudding is fine. Its just sitting around at room temperature that is the problem.
So if you're not going to eat rice straight after you've cooked it, then you need to store it in the fridge â as soon as possible, but definitely within four hours. Refrigeration won't kill the bacteria but it will slow down its growth â any uneaten rice should be thrown out after three days in the fridge. Moir says this type of food poisoning is less frequent now than it was in the 1970s, when fried rice was a common culprit.