The bleached one is white and the unbleached one is brown. The bleached one may contain toxic dioxin and which can leach when heated. It can be harmful to your health and cause many health problems. So, it’s better to use unbleached parchment paper.
Subsequently, is there brown parchment paper?
As you’d expect from the name, bleached parchment is white, while unbleached parchment is brown. This is because unbleached parchment paper is untreated and totally chlorine-free, while its bleached counterpart is treated with chlorine, producing that gleaming white color.