Now, let's understand something. Pesticide is a general term for more specific chemicals that eliminate pests. You're more accurate if you say insecticide, fungicide, rodenticide and herbicide. Well, unwanted plants are pests aren't they?
The first rule of pesticide safety is 'clean up first.' If you can clean up an area that invites pests, maybe you can solve your problem. Get rid of food sources and hiding places. Keep foods (including those for pets and wild birds) in plastic and glass containers if necessary.
Besides getting rid of food sources, block entryways to your house. Caulk cracks and holes. Apply expanding foam insulation to seal large cracks and openings in semifinished areas of the house. Buy or make face plates for places where pipes and wiring come in through walls. In my garage, I keep a great number of fabric-like things in plastic tubs to keep mice from nesting in them.
Outside, clean up rotting vegetation alongside the house to discourage insects, rodents, mold and in some places, snakes. As far as I am concerned, a skunk is a pest too.
The second rule of pesticide safety is 'use mechanical devices.' Some people import insect helpers such as praying mantises and ladybugs for outside pest work but these won't help in the house. Nor will purple martin and wren houses. Inside, sticky insect traps and mechanical mouse traps are a good line of defense. For mice, you also can use a cat or a large pet snake. Just kidding about the snake.
When all else fails and you must resort to pesticides, accept the fact that if they can kill pests they can't be too good for you. The first rule of using pesticides is 'read the label.' All legal pesticides in the United States carry an approval label from the Environmental Protection Agency. If the product isn't approved, you shouldn't have it in the first place. If a label tells you a pesticide is 'restricted,' don't use it unless you have been properly trained and certified. Training and certification wouldn't be required if experts didn't think the pesticide was more than just a little toxic. How much can it hurt to err on the side of caution?
Read the label because even if you used a pesticide before, you probably won't remember exactly how much to mix or apply, how and where to apply it, how to clean up afterward, and how much care to take in using the product. How much can it hurt to take a few minutes to read the label? The words 'DANGER,' 'WARNING' and 'CAUTION' warn you how hazardous a pesticide is, from more to least.
Pesticide labels also tell you what pests a particular pesticide is good for, how much to mix, and how much to spread (granular), place (bait), dust, mix (solutions and wettable powders), and spray (aerosols and solutions). A manufacturer knows its product's strengths and weaknesses - literally. Mixing or applying too much or too little is a mistake. Twice as much of something doesn't necessarily kill anything faster!
Where you mix a pesticide can be important. Pesticide vapors can overwhelm you in an enclosed area. Also, application in an enclosed space could concentrate lasting vapors that you may want to vent safely.
Wear long pants, long sleeves, rubber gloves (not canvas or leather), full-cover footwear, a hat, and goggles. A vapor-barrier respirator wouldn't hurt but might be extreme for around-home use of pesticides.
Keep pesticides away from children, pets, birds, fish ponds, food and yourself. Don't let pesticides get near foods, utensils, glasses, dishes, pots, counters, kitchen towels and whatever else might come in contact with food or otherwise be ingested. Be especially mindful of children's toys. One way or another, either the toys or the child's sticky fingers that touched the toys get put in the child's mouth. Be extra careful to place baits out of reach where children cannot get at them.
Keep pesticides away from wells, ponds, water supplies, blooming plants, honeybees and other pollinating insects, and birds and their nests.
Use up all pesticide before discarding its cleaned container. Clean the container by filling it with water and applying the solution as if it was a regular pesticide mix. Then discard the container in municipal trash. Never reuse it.
Never transfer pesticide from one container to another of any kind. First, it negates the warning label and instructions. Second, it mixes potentially incompatible chemicals. Third, you'll forget when you bought it and what it as for.