Various baby food makers were brought before a California judge on Monday following accusations that they failed to warn the public of possible lead contamination in their products.

In the first day of a four-week trial, California Supreme Court Judge Stephen Brick heard testimonies regarding the poor business practices by companies such as Gerber Products, Del Monte Foods, and Dole Food Co.

A suit filed back in 2011 by the Environmental Law Foundation argued that the food companies were in violation of California Proposition 65, a law requiring that any product containing high levels of lead must be accompanied with a warning label.

The company's legal counsel argues the lead in their products is occurs naturall in the fruit and vegetables used to make the baby food. If the trial judge finds that this is true, he could exempt the companies from having to warn consumers, USA Today reported.

"Despite the trace amounts of lead in the products at issue, the federal government has determined that Americans need to eat more — not less — of these nutritious foods," the companies' attorney, Michele Corash, wrote in court documents. "FDA recently reiterated its conclusion that the trace levels of lead in the products at issue in this case do not pose unacceptable health risks."

The Centers for Disease Control and Prevention estimates there are at least four million households with children who are being exposed to dangerous lead levels.

The CDC also offers these preventative measures to protect against lead exposure:

1. Talk to your state or local health department about testing paint and dust from your home for lead.

2. Make sure your child does not have access to peeling paint or chewable surfaces painted with lead-based paint.

3. Pregnant women and children should not be present in housing built before 1978 that is undergoing renovation.

4. Create barriers between living/play areas and lead sources.

5. Regularly wash children's hands and toys. Hands and toys can become contaminated from household dust or exterior soil. Both are known lead sources.

6. Regularly wet-mop floors and wet-wipe window components.

7. Prevent children from playing in bare soil; if possible, provide them with sandboxes.