1. in vitro testing of fiber dissolution so dif- iron could be deleterious as it would be
2. ferences between laboratories cannot ade- free to take part in free radical-generating
3. quately be ascribed to any particular part reactions (6). This could be responsible
4. of the methods used. Despite this lack of for the high radical generating activity of
5. standardization the same general trends rockwool reported by Fournier et al. (7).