This quote is from this link on the Shell website, aviation fuels for civil aircraft.
http://www.shell.com/home/content/av..._10081004.html
Former Soviet Union and East European Jet Fuels
Soviet kerosine type jet fuels are covered by a wide range of specification grades reflecting different crude sources and processing treatments used. The grade designation is T-1 to T-8, TS-1 or RT. The grades are covered either by a State Standard (GOST) number, or a Technical Condition (TU) number. The limiting property values, detailed fuel composition and test methods differ quite considerably in some cases from the Western equivalents.
The principle grade available in Russia (and members of the CIS) is TS-1.
The main differences in characteristics are that Soviet fuels have a low freeze point (equivalent to about -57 degrees C by Western test methods) but also a low flash point (a minimum of 28 degrees C compared with 38 degrees C for Western fuel). RT fuel (written as PT in Russian script) is the superior grade (a hydrotreated product) but is not produced widely. TS-1 (regular grade) is considered to be on a par with Western Jet A-1 and is approved by most aircraft manufacturers.
Eastern European countries have their own national standards with their own nomenclature. Many are very similar to the Russian standards but others reflect the requirements of visiting international airlines and are similar to Western Jet A-1 in properties and test methods.