Most beer line cleaning chemicals are harmful or fatal if swallowed. Therefore, when cleaning beer lines, it is important to always rinse lines throughly. To ensure chemicals are throughly rinsed from lines, it is recommended to always check the pH level of the rinse water. If not within the normal 7.0—8.0 range, then it is likely that chemicals are still present within the lines and additional rinsing is necessary.

The pH testing paper, also known as litmus paper, is dipped in the rinse water and changes colors to indicate pH value. Then simply match color of paper to the color chart on the thermoplastic dispenser to ensure a pH value of 7.0—8.0.