What is the normal pH level considered safe for NG tube testing?

A normal pH level considered safe for confirming placement of a nasogastric (NG) tube is 4 and below. This pH range indicates the presence of gastric contents, which are acidic due to the secretion of gastric acid (primarily hydrochloric acid). When the pH is at or below this level, it suggests that the tube is correctly positioned in the stomach rather than in the esophagus or respiratory tract.

In practice, the typical pH of gastric contents can range from about 1 to 4; therefore, a pH of 4 and below would be a reliable indication that the NG tube is indeed in the gastric area. A pH higher than 4 could indicate that the tube is not in the stomach, which poses risks for complications such as aspiration if the tube is misplaced.