Yes. The limit of 2 watts per kilogram for cell and smart phones has been fixed in the EU Council's recommendation in 1999 and applies in Germany as well as in all other European countries.
All cell phones are designed not only to comply with the defined limit of 2 watts per kilogram but also to remain well below it (adaptive power control).
The limit is based on the recommendations of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), a committee of experts recognized by the World Health Organization (WHO). ICNIRP reviews the validity of the limit values on an ongoing basis. It currently concludes that it is safe to use mobile communications provided that the limit values are ensured.