Michael A. Pinto, CEO, Wonder Makers Environmental, of Kalamazoo, Mich., said there usually are visible clues that can help in identifying spills and leaks, such as oil floating in the water or hanging on the side of a dry wall where there’s a lot of damage. “You can also smell things,“ he says. “The best approach is to just assume that everything that was touched by that storm water is contaminated,” because there might not be a lot of clues.

Pinto advises agents and brokers to tell homeowners that when there is a major storm, they should get acquainted with the type of storm, which will determine what is to be done to protect chemical spills and leaks. If you're in low-lying areas, where the primary concern is flooding, take hazardous chemicals, such as paints, cleaners, and gasoline, separate them in plastic containers and move them to the upper floors. If you're inland, where the brunt of the storm will be high winds and wind-driven rains, then move the chemicals to lower levels. For example, if the chemicals are in upstairs bathrooms, move them downstairs or to the basement.

EPA has provided the following six tips on how residents can safely remove household hazardous waste.

(Photo: Shutterstock/Africa Studio)

1. Don't combine chemicals.

Mixing household chemicals and cleaners can produce potentially toxic vapors that can be very dangerous, even deadly. Some household chemicals are basic, and some are acidic; mixing them can make some end products ineffective, while others may react violently to cause chemical burns. You don't know what kind of reaction you'll get, says Pinto, " but most of them are going to be bad." He adds that simple household materials, such as bleach and ammonia—when mixed—can quickly become phosgene gas, which is a colorless deadly gas. Other mixtures, such as gasoline and rubbing alcohol can create explosives.

(Photo: Shutterstock/Gary Whitton)

2. Don't pour chemicals down storm sewers, drains or toilets.

Dumping chemicals down the toilet or drains may contaminate the public water supply and could introduce toxic chemicals to the marine environment, potentially damaging our ecosystems. "You never want to put anything into the storm drain because that just puts it back into the river and the oceans, and that could be bad from an environmental standpoint," says Pinto.

Wastewater treatment plants also can become overwhelmed after a storm, he adds, "and if [people] start adding all of these extra chemicals and hazardous materials," it somehow worsens the situation. He suggests getting garbage cans or bags to put the chemicals in, or using the centers or collection points usually made available by the government specifically to handle hazardous wastes after a major storm.

(Photo: Shutterstock/Monticello)

3. Don't burn household chemicals.

Burning household chemicals can lead to inhaling pollutants, which can increase health risks. Children, the elderly and people with preexisting respiratory conditions can be adversely affected. When burning debris, separate the following for proper disposal: automotive and marine batteries; pesticide cans; automotive oils; fuels and fluids; solvents; paint thinners and stripper; and compressed gas containers.

Pinto suggests that when cleaning up after a storm, people with respiratory or other health conditions use a good respirator, such as the N100, not just a dust mask. He said any clean-up effort used will take the chemicals that are contaminating things and make them airborne, so “you end up getting it in the air no matter how careful you try to be,” and this could lead to serious health issues.

Related: The Dangers of Combustible Dust

(Photo: Shutterstock/Sparkstudio)

4. Keep children and pets away from leaking or spilled chemicals.

Children and pets are susceptible to the effects of exposure to hazardous chemicals.

Call 9-1-1 if you suspect someone has been exposed to dangerous chemicals.

Report chemical spills to local authorities or the EPA National Response Center by calling 1-800-424-8802.

(Photo: Shutterstock/Monticello)

5. Mark and set aside unbroken containers for proper disposal.

Some people tend to wash and store unbroken containers of chemicals after a storm, hoping to use them in the future. Pinto says that most of the things that we as homeowners tend to store—assuming that we're going to use them in the future—we make efforts to wash off but "we don't know if we've gotten it 100% clean." If the item was in an area of the home that was impacted by the flood waters, unless it's very valuable or can be easily cleaned, dispose of it and restock it. He adds that many times labels are damaged, and people don't always remember what is or was in the container.

(Photo: Shutterstock/Liusa)

6. Repackage and label damaged containers.

In the event of a storm, and especially if your home will be evacuated, Pinto suggests that all hazardous materials be removed from bathroom cupboards or closets and be placed in the bathtub with a closed drain. "Anything that tips over and spills will be easier to clean up from the tub," he notes.

To prevent leakage, broken or damaged containers should be placed in a secondary container and marked and labeled for easy identification.

Chemicals also can be moved to the garage, if one is available, where water enters and usually leaves. Chemicals, such as fertilizers, gasolines, pesticides, rat poisons and moth balls, if dispersed, will contaminate finished materials, such as cement, dry-wall and upholstery. Storing such chemicals outside the house will save on the expense of repairs, says Pinto.

Serious flooding in the Sheapsheadbay neighborhood due to the impact from Hurricane Sandy in Brooklyn, New York, October 30, 2012. (FashionStock.com/Shutterstock.com)

Here are some additional steps Pinto suggests people consider in the event of storm:

• Depending on the type of storm and the type of damage, people "have to be aware that there are going to be hazardous materials, most likely in the storm-damaged areas.” After both Hurricane Katrina and Superstorm Sandy, it was pretty clear that the flood waters—even the ocean flood waters—carried a large number of hazardous materials, bacteria and viruses, oils, pesticides, and heavy metals that were contaminated.

• Pay attention to government restrictions and obey them. Start cleaning up as soon as emergency officials issue authorization to move back into the community. Sooner is better.

• Depending on the damage, people should seek professional help if they're unsure of what hazardous materials they may be exposed to. It's extremely important to use protective equipment when cleaning up: “boots, long pants, gloves that come up over the wrists, respiratory protection, eye protection—all of that is critical,” Pinto says.

• Avoid storing chemicals that are very reactive or self-combustible in the home. They could easily start a fire. Any kind of fuel for barbecue grills or camp stoves, law mowers or snow blowers—such as propane gas, gasoline, kerosene or diesel fuel—is best stored in a garage, not in the house.

• Once a year, people should think about spring cleaning. If you find anything that's been under the sink, in the basement or in the garage for more than a year and hasn't been used, “dispose of it properly and replace it,” Pinto says. Use up chemicals, but if you don't, they're just a danger to keep around.

• Businesses usually have compressed gas tanks, often chained to walls, which are likely to be moved by the flood waters and scattered. This could cause safety problems, because the tanks may leak. Large containers of nitrogen that are leaking can disperse in the air and could result in suffocation of maintenance personnel or anyone cleaning up. Pinto strongly suggests that businesses have pre-disaster arrangements with a professional restoration company, use efficient breathing apparatus and have clean-up done by professionals.