Before you hire that contractor or start a DIY construction/deconstruction project in your home, it's so very important to be aware of possible toxic materials being used for the job, as well as safety hazards. Even natural materials can pose dangers. In doing so, you will help insure the safety and health of your household and everyone in it.
Recently, I arrived at a clients home who was in the midst of a bathroom remodel. While there, I observed a number of things that I found unsettling. There were tools and building supplies scattered throughout the house, heavy tiles sitting on furniture, as well as a thick layer of dust on every item in the home. Some of these building materials are pretty harmful. Even if they have no VOC's (Volatile Organic Compounds) For example: I noticed a bag of Ditra-Set sitting open on the living room floor and some of the contents had spilled out. Ditra-Set is a quick set cement used to adhere tile, stone, flooring, etc.. It is composed of Silica Quartz. Now, Silica IS a mineral and it is natural but, it's harmful to breathe and can cause a number of permanent health issues. While the family had been away all week, their cats were still at home and exposed to the surrounding dust.
Whomever is doing the job should be doing their tile cutting outside (weather permitting), If they are unable to do so, the area in which they are cutting their tile should be sealed off with plastic, as should the area in which the demo is being done. If there are bedrooms close by, the doors of the bedrooms should also be taped off with plastic and doors should be closed. The plastic can be removed at the end of the work day. This keeps the majority of dust contained. You can also help keep the dust levels down even more by occasionally misting your living spaces with a spray bottle filled with water or by purchasing a humidifier.
If there is adhesives, paints, sealants, and varnishes being used that can emit volatile organic compounds, be absolutely sure there is proper ventilation. Position fans in windows so that they bring inside air out. Purchasing a small air purifier would also help with fumes. Though, there are many options for alternatives that do not contain VOC's which should be your first choice
The work areas should be cleaned at the end of each day and materials and tools placed together in an area restricted from children and pets. For example: saws and tile cutters should never be left out. Children are especially curious at times and could wind up in a horrible situation. As a child I got a hold of a caulking gun that my mother had left out ,and proceeded to caulk the face of one of my barbie dolls. While this was not harmful to myself, my poor barbies face was not the same after her "plastic surgery".
There are plenty more areas of hazards to be aware of but, these just so happen to be the few that I had noticed at this home. Do your research, be aware, and don't be afraid to make suggestions to your contractor if you feel there are any areas of concern.