When choosing the right school for their children, many parents ask about class sizes, the community, learning objectives and schedules.

But what about toxic chemicals in schools? After home, children spend more time in school than anywhere else. While many parents make important choices to protect their children from toxic chemicals in their homes, at school these factors may be off a family’s radar.

So how can parents keep their kids safe? Start by learning more about the school environment.

Here are five questions to ask your child’s school:

  1. What year was the school built?

Old buildings may contain toxic construction materials such as lead, asbestos and PCBs.

Prior to the lead paint ban in 1978, builders covered both building interiors and exteriors with it. This old paint remains in many places today, and crumbling or peeling surfaces continue to be a main source of toxic lead exposure for children.

Another building danger is asbestos. A 2015 Washington Post report revealed that exposure to this hazardous substance persists at schools across the United States. Although builders used asbestos mostly between the 1940s and the late 1970s, it is still legal today and it’s in more places than you would think.

Schools are required by law to track asbestos hazards and disclose their mitigation plans to parents. Ask your school about its plan to manage asbestos and any upcoming renovations.

  1. What’s in your drinking water?

Children use school water fountains throughout the day. But does this tap water contain harmful contaminants like lead, perchlorate or atrazine?

Possibly. Public drinking water utilities test water regularly for harmful contaminants, so ask your school which utility serves the school and check its tests results. Many utilities post this information online, and it is also available in EWG’s Tap Water Database. If you live nearby, the results may be the same for your own household.

Many schools are rightfully encouraging kids to bring water bottles instead of juice boxes or wasteful bottled water. Ask whether students have access to filtered water, and check your school’s classroom bottle policy if you want to send your child to school with filtered water from home.

  1. What products do the school cleaners use?

The janitorial workers may bring countless chemicals into school every time they clean, leaving chemical residues on the desktops, chairs and doorknobs your children touch regularly. Ask your school about the products being used, by whom and how often, and check the ingredients using EWG’s Guide to Healthy Cleaning.

Inquire about cleaning equipment as well: Do the vacuums have a high-efficiency particulate air, or HEPA, filter installed? They should.

If the answers may put your child at risk, talk to school administrators about safer options and what it takes to swap. There are good options on the market that limit chemical use and stay within tight budgets.

  1. Are pesticides sprayed near your school?

The use of genetically engineered crops has led to a sharp increase in the use of herbicides, such as glyphosate. An EWG report shows that more than 3,000 elementary schools nationwide are located within 1,000 feet of a corn or soybean field. And it’s not just schools: Nearly 12,000 churches are within this distance from glyphosate-sprayed fields, as well as more than 90 percent of playing fields and parks in a six-state sample.

It is not just corn and soybeans. Many types of crops and non-crop areas such as rights-of-ways can be sprayed with pesticides. Ask what school personnel are doing to help reduce student exposure to pesticide drift. Are janitors cleaning surfaces more often? Has the school set up hand-washing stations?

  1. How sunny is your playground?

The best ways to protect your kids from harmful sun damage are to cover up, stay in the shade, and use a safe and effective sunscreen.

Ask about school policies about hats and sunglasses, whether shade is available on the playground, and what times of day outdoor play is scheduled. When your school administrators know what’s important to your family and why, they are more likely to work with you on it.