masksafety
Is there a standard mask to protect the lungs when cutting Hardie board? While specifics masks suggestions are appreciated, I am trying to understand how to avoid sub-standard masks and avoiding injury.
For additional context see Can I use this blade to cut Hardyboard?
Usually that warning applies only in California—most states are not at risk. :-)
The carcinogen involved is cement dust, specifically its components of tri- and dicalcium silicate, alumina, tricalcium aluminate, and iron oxide. The hazard extends to skin, eyes, mouth, and respiration.
To be completely protected, a moon suit (made of Tyvek in the photo) is in line with the most pessimistic expectations. However, the practical alternative (and recommended by CDC and OSHA) is any quarter-mask respirator with an N-95, R, or P filter to arrest fine particles, along with gloves, and enclosed eye protection—and avoiding unnecessary cement contact.
Many workers are skeptical of the carcinogenic property of cement dust: it is common to see experienced workers taking only minor precautions. Usually wearing only a mask while handling the powder. Once it is moistened and and dust is no longer a factor, most don't do anything special. But it is a strong caustic alkalai, so do take care not to get it inside or on you for an extended time.
Per the Michigan State Handbook for Public Playground Safety:
It is recommended that the average incline of a slide chute be no more than 30 degrees. This can be measured by determining that the height to length ratio (as shown in Figure 18) does not exceed 0.577. No span on the slide chute should have a slope greater than 50 degrees.
There is some other really good information in that booklet as well regarding the design of a slide.
Best Answer
Assuming you are talking about HardieBacker cement board, the manufacturer's SDS (Safety Data Sheet) recommends using an N-95 (minimum) respirator/dust mask. But there are other best-practices for preventing exposure to the dust (the dust contains crystalline silica).