A Universally Recognized Accessibility Symbol for Environmental Sensitivities?

https://goo.gl/ophjSN

We need an easily recognizable accessibility symbol for non-toxic, wireless, VOC, scent, and fragrance-free places that show they are accessible to people with MCS/ES, asthma, COPD, migraines, and others who need healthy environments in order to remain functional and not become physically or cognitively impaired.

These signs would be used only in places that actually enforce the policies.

The standard accessibility signs have white symbols on blue backgrounds like these: