In April 2018, I traveled to Denver for the annual Early Childhood Design conference. A standout presentation was one by Paula Burns McEvoy, from Perkins and Will, who spoke about the hidden toxins in commonly used building materials. She's the force behind the Transparency website, which has an abundance of information on building materials and what they contain.
https://transparency.perkinswill.com/

In early childhood spaces that are licensed by the state, there is an inherent conflict between health policy as determined by the Department of Health (i.e., no germs) and the risk to health by some of the chemicals used to protect us - plastics, disinfectants, foam, flame retardants.
https://www.ewg.org/healthychildcare

So what to do?

1. Get VCT off of the floor. Yes, it is inexpensive, but vinyl is a probable risk to human health. Small children spend most of their time on the floor. Here are my favorite alternatives:
   - Linoleum. Real linoleum is fabulous!
   - Wood - but watch for formaldehyde
   - Cork
   - Rubber
2. Select furnishings and toys carefully. Look for Greenguard certifications for furniture; here's a link to a searchable directory for early learning furniture. Even Greenguard-certified products (nap mats!) may have foam and vinyl, so consider other options, such as cots.
   
3. Get outside & bring fresh air in. If you have an older mechanical system with inadequate air delivery, consider installing an ERV (energy recovery ventilator) to bring in fresh air without sacrificing on heating costs.
   

In February 2018 I had the opportunity to visit the Taleny School in Guadalajara, México, designed by Aro Estudio. It's a beautiful campus that houses students from preschool through middle school. The climate allows for a very integrated site and building, with exterior walkways and courtyards, breezeways and an abundance of skillfully controlled natural light.