1. Polyamide 6 Grades Are Claimed To Meet New Gas-Permeation Rules
2. http://www.plastverarbeiter.de/texte/anzeigen/9575/
3. http://lanxess.com/de/presse/presseinformationen/fachpresse/performance-polymers/detail/18813/
4. RAL-UZ 129: Low-Noise and Low-Pollutant Garden Tools (RAL-UZ 129), 04-2010
5. http://www.eval.eu/en/applications/automotive/emission-regulations