An FAA Designated Engineering Representative (DER) is an engineer who is appointed under 14 CFR section 183.29 to act on behalf of a company or as an independent consultant. The DER system enables the FAA to reduce its direct employee aircraft certification workload by delegating certain involvement in airworthiness exams, tests, and inspections to qualified technical people outside of the FAA. Qualifications and policies for the appointment of Designated Airworthiness Representatives are established in FAA Order 8100.8, Designee Management Handbook. Working procedures for DERs are prescribed in FAA Order 8110.37, Designated Engineering Representative (DER) Handbook.
Company DERs act on behalf of their employer and may only approve or recommend that the FAA approves technical data produced by their employer. Consultant DERs are appointed to act as independent DERs and may approve, or recommend that the FAA approves technical data produced by any person or organization.
Neither type of DER is an employee of either the FAA or the United States government. While a DER represents the FAA when acting under the authority of a DER appointment, a DER has no federal protection for work done or the decisions made as a DER. Similarly, the FAA does not warrant any DER work and does not provide any indemnification for a DER from general tort law.

The European Union Aviation Safety Agency (EASA) is an agency of the European Union governed by European public law and represented by 31 different countries. EASA is an independent and neutral body and is responsible for ensuring confidence in safe air operations in Europe and worldwide by proposing and formulating rules, standards, and guidance; by certifying aircraft, parts, and equipment; and by approving and overseeing organizations in all aviation domains.
www.easa.europa.eu

The International Civil Aviation Organization (ICAO) is a United Nations agency that helps 193 countries to cooperate and share their skies to their mutual benefit. ICAO was established in 1944.

The United Kingdom Civil Aviation Authority (UK CAA) is responsible for the regulation of aviation safety in the UK, determining policy for the use of airspace, the economic regulation of Heathrow, Gatwick, and Stansted airports, and the licensing and financial fitness of airlines.
CAA is a public corporation of the UK Department for Transport.
www.caa.co.uk/

Transport Canada is the department within the Government of Canada responsible for developing regulations, policies, and services for road, rail, marine, and air transportation in Canada. Transport Canada is headquartered in Ottawa, Ontario.
Transport Canada is responsible for enforcing several Canadian legislations, including the Aeronautics Act, Transportation of Dangerous Goods Act, 1992, Motor Vehicle Safety Act, Canada Transportation Act, Railway Safety Act, Canada Shipping Act, 2001, Marine Transportation Security Act, and others.

tc.canada.ca

The U.S. Food and Drug Administration (FDA) is the government agency responsible for protecting public health by assuring the safety, efficacy, and security of human and veterinary drugs, biological products, medical devices, the US food supply, cosmetics, and products that emit radiation.
www.fda.gov

The Center for Devices and Radiological Health (CDRH) is a sub-organization of the U.S. FDA, responsible for the premarket approval of all medical devices, as well as overseeing the manufacturing, performance, and safety of these devices.
The CDRH also oversees the radiation safety performance of non-medical devices that emit certain types of electromagnetic radiation, such as cellular phones and microwave ovens.
www.fda.gov/cdrh