Certification is optional for numerical control machine operators. Certification is given by trade associations in the metalworking and plastics industries. It generally requires work experience and passing an exam.
For more information on certification for machine operators who work with plastic, contact:The Plastics Industry Association
1425 K Street N.W., Suite 500, Washington, DC 20005
Phone: 202.974.5200, Fax: 202.296.7005