From the website of the company (I got curious they really don't feel like 'plastic' but wasn't sure exactly WHAT they were made of)
We not only set tight controls for ourselves and our production stages, we begin with our materials suppliers. They are only approved for use in Schleich products if they are aware of the quality of their processes and materials, comply with international toy regulations and can present the relevant laboratory reports.
The main materials we use are a variety of plastics and a special softener. We make sure that this is used in the same way all over the world so that small parts cannot break off our figures and the material is pleasant to the touch and not too hard. This softener was developed and tested by BASF for particularly demanding applications. It is not only approved for use in toy manufacturing but also for food packaging and for use in the medical field for example as bags for blood products, breathing tubes etc. This means that here too, we are meeting all legal requirements.
Schleich quality assurance staff check and control all production premises as well as our materials suppliers every year.