The following list mentions the 52 ADR member states in which it is obligatory to carry the known dangerous goods plates:
Albania, Andorra, Austria, Azerbaijan, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Iceland, Ireland, Italy, Kazakhstan, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Macedonia, Montenegro, Morocco, Netherlands, Nigeria, Austria, Belarus, Norway, Poland, Portugal, Republic of Moldova, Romania, Russian Federation, San Marino, Serbia, Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Tajikistan, Turkey, Tunisia, Czech Republic, Ukraine, Hungary, United Kingdom, Uzbekistan