Which carpet fiber is least likely to be affected by bleach?

Olefin, also known as polypropylene, is a synthetic fiber that is highly resistant to bleaching agents, making it the least likely to be affected by bleach among the options provided. This resistance is attributed to olefin's chemical structure, which does not easily break down in the presence of strong oxidizing agents like bleach.

In contrast, other fibers such as wool, acrylic, and cotton have more susceptibility to chemical damage from bleaches. Wool is a natural fiber that can be significantly affected by bleach, leading to discoloration and weakening of the fibers. Acrylic, while more resistant than wool, can still be degraded by bleach, which may change its color or cause brittleness. Cotton is also vulnerable to bleach, as it can lose its color and integrity when exposed to such chemicals. Thus, olefin stands out as the best option for areas where bleach might be used, either inadvertently or intentionally.