Cellulose Insulation

Frank, it really depends on when the cellulose was installed. Most modern day cellulose is treated with borate which is a natural mold inhibitor, as well as, a fire retardant. In addition, the paper is hygroscopic which means it disperses the moisture quickly. With proper attic ventilation, this means the cellulose will dry out fast and not allow the mold to grow (no water = no mold). While the water was present, the borates will inhibit the mold growth until it does dry. However, if the cellulose was an early version (say, pre-1977), it may not have been treated. Prior to about 1977, cellulose was not required to have a fire treatment in them. There were a lot of homes stuffed with paper and you can imagine what happened in a fire. Now that the fire retardants are required, homes are much safer. So, based on the age of your home or when you know it was insulated, will be the answer to your question.