Butylated Hydroxytoluene (BHT) is a poorly-tested chemical preservative and has been implicated as a cause of liver damage, metabolic stress, fetal abnormalities and serum cholesterol increase.

BHA and BHT are the most common human and pet food preservatives. These antioxidants protect fats and oils from becoming rancid and developing an off flavor. The FDA has determined that these antioxidants are safe and effective when used in the recommended quantities of less than 200 ppm of the fat or oil content. Federal officials carefully monitor the extent of consumption of the additives, and the results of any new research to assure its continued use within safe levels.

In general, foods will spoil without some form of temperature control or preservatives. BHA, BHT, and ethoxyquin are chemical antioxidants designed to extend the shelf life and reduce fat spoilage (rancidity) of pet foods and pet treats. Chemical additives and artificial preservatives such as BHA, BHT, and ethoxyquin may cause dry skin, allergic reactions, dental disease, and poor health, as well as stimulate adverse effects on liver and kidney functions.

BHT is a preservative and antioxidant used as a chewing gum base for potato and sweet potato flakes and dry breakfast cereals. Also, an emulsion stabilizer for shortenings in enriched rice, animal fats, and shortenings containing animal fats. Also used to retard rancidity in frozen pork sausage and freeze-dried meats. Shown to cause offspring that have abnormal behavior patterns secondary to chemical changes in the brain (study in mice).