Pool chemicals are not toys and should be handled with caution. If mistreated and that means the amount you also add to your pool in the cause of sanitation, they can do more harm than good. Here's some points to remember courtesy of Lowes.com. While pool chemicals are available to solve almost all water problems, they can be dangerous to humans and animals if handled improperly. Chemicals can cause skin and eye damage and can be fatal if swallowed.