Some Construction Applications and Related Possible Health Hazards Indoors

3 Some Construction Applications and Related Possible Health Hazards Indoors 

In following sections, some construction applications of polymers will be summarised. Each construction material should be considered first for the possible inherent hazard(s) involved, which were presented before, if they are not specifically mentioned next. 

As briefly discussed previously, PCB, a family of highly toxic and oily, non-flammable industrial chemicals, can exist at high levels in and around some old buildings due to the sealants based on polysulfide polymers containing PCB. PCB in many polysulfide sealants have been replaced now by chlorinated paraffins, and smaller volumes of chloroparaffins are used as plasticising agents for various sealants. However, the effects of chloroparaffins on health, is also a controversial issue, and its use in sealants is in decline. In sealants, especially in polysulfide and PU sealants, the BBP is also used. 

Polyurea seals are 100% solid, with high elongation self-levelling elastomers. They are completely VOC free, used in horizontal saw or preformed joints on concrete or asphalt. 

The Clean Air Act demands the elimination of organic solvents use, hence a number of plasticisers and solvents (such as methylene dichloride (MEK), toluene, xylene) are classified as hazardous, which led to development of new, environment compliant systems to develop, such as water borne systems, or use of rapidly curable/dryable oligomers (i.e., printing inks use oligomeric bis acrylates, polyester acrylates and polyurethane acrylates, which can be crosslinked quickly by UV light with the aid of certain sensitisers). 

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