Removes cellulose and tannin browning from carpet and upholstery. Cellulose browning is often caused when natural fibers, such as cotton, jute or other natural fibers, are cleaned and the drying process is prolonged. Tannin stains also come form coffee and teas. Browning Treatment is an effective treatment for correcting these types of browning. It will correct or reduce browning quickly in an easy one-step application. Ready to use pH is 4.0.