The need of the calcium silicate board (reinforced with selected fibers and fillers, mainly made from cement, quartz sand and reinforced fiber) have been increased year by year. With government encourage manufacturers to use recycle materials for producing building materials in recent years, the recycle industrial by-product such as fly ash and slag can be used as alternative materials to the boards manufacturing. Labors in manufacturing workplaces and decorating the construction site for boards cutting operation may inhalant dust which containing recycled raw materials. Toxicity characteristic leaching procedure (TCLP) is conducted by Taiwan Environmental Protection Admistration (TEPA) to exam these heavy metal-containing recycle materials from waste. It is necessary for wastes to pass TCLP tests before reusing. However, worker’s exposure from heavy metals is considered as dust inhalation not TCLP tests. The survey on workers’ exposure to dusts and heavy metals during boards manufacturing and cutting work (using electric circular saw) is conducted by onsite dust sampling. Results from dusts exposure sampling showed that the average total dust concentration in the factory is 0.138 mg/m3, the average respirable dust concentration is 0.096 mg/m3. The maximum total dust concentration is observed in cutting area as 0.269 mg/m3. Furthermore, results from heavy metal analyses revealed that the recycled material A containing Ni 375 mg/kg, As 87.2 mg/kg; the recycled material B containing Cu 145 mg/kg, Ni 80.0 mg/kg, As 75.0 mg/kg; the recycled material B containing Ni 70.0 mg/kg. Nevertheless, the results on workers’ exposure to heavy metals during boards manufacturing and cutting work showed all the heavy metal concentration is below detection limit. It is worth notice to pay attention on recycled materials usage increase and change.