Oct. 6, 2011  2  US 2011/0245219 Al  the polio virus type 1, LSc-2ab and fulfills the requirements of  the DVV/RKI Guideline. However, disinfectants with such a  high alcohol content have critical disadvantages. Thus the  flash point is mostly very low, as a result of which special  precautionary measures must be taken during transport, stor› age and use.  [0020]  EP 1 685 854 Al (B. Braun Medical AG) relates to  a virucidal disinfectant with broad spectrum action, which is  based on alcohol, acidic phosphorus compounds and poly› alkylene glycols. The disinfectant also fulfills the require› ments of the DVV/RKI Guideline, but is relatively acidic,  which can cause reddening of the skin, itching or burning in  the user.  [0021]  In WO 91/35475 (Antiseptica Chemisch-Phar› mazeutische Produkte GmbH) virucidal disinfectants for the  hands are described which contain ca. 50-60 vol. % oflower  alcohols and to increase the viral action are for example  treated with 3-10 vol. % of dials. However, during the disin› fection of the hands the dials at least partially remain on the  skin and can cause an unpleasant feeling on the skin.  It  is not  clear against which viral strains these disinfectants are effec› tive and whether for example the standard EN 14476 (2005)  or the DVV/RKI Guideline from the year 2005 are fulfilled.  [0022]  Clearly the known virucidal disinfectants are not  entirely satisfactory. There is thus still a need for virucidal  disinfectants which do not exhibit the aforesaid disadvan› tages.  [0023]  Hence the purpose of the invention is to create a  virucidal disinfectant lying within the technological field  stated at the outset, which exhibits improved activity against  as many different pathogens as possible and in particular is  tolerated by the skin.  [0024]  The solution to the problem is defined by the char› acteristics of claim  1.  According to the invention, the viru› cidal disinfectant contains urea.  [0025]  In this context, acidic compound or acids are under› stood to mean chemical compounds which in particular func› tion as proton donors in the sense of a Bronstedt acid and/or  as electrophilic electron acceptors in the form of a Lewis acid.  Here the acidic compound can for example be present as an  organic chemical and/or as an inorganic chemical compound,  where a content of the acidic compound in the disinfectant is  inter alia also determined by the acid strength or the  pKa  value. The acidic compound in particular exhibits a  pKa  value  of3-5, particularly preferably 3.5-4.0. The  pKa  value should  be understood to be the negative decimal logarithm of the  equilibrium constant  Ka  of the acidic compound in water at a  temperature of 25°  C.  [0026]  A minimum content of acidic compound is prefer› ably at least 0.1 wt. %. Such minimum contents have also  proved advisable with strongly acidic compounds. However,  the minimum content of acidic compound is inter alia also  dependent on the acid strength of the acidic compound and  can therefore vary.  [0027]  In this context, urea is understood to mean carbonic  acid diamide with the molecular formula CH$_{4}$N$_{2}$0. Urea, not  to be confused with uric acid, is inter alia also referred to as  carbamide, carbonyl diamide, diamide of carbonic acid and/  or urea. In practice, a minimum content of urea is in particular  at least 0.2 wt. %.  [0028]  All statements relating to percentages by weight or  wt.% of individual components of the disinfectants accord› ing to the invention are based on the total weight of the usable  or ready to use disinfectant.  [0029]  The expression "alcohol-based" means in particular  that a main component of the disinfectant consists of alco› hols. The main component here is in particular that compo› nent of the disinfectant which of all the components of the  disinfectant present has the greatest proportion by weight.  [0030]  It  has surprisingly been found that disinfectants  based on the combination of an alcoholic main component  with at least one acidic compound and urea exhibit extremely  good virucidal efficacy, in particular against the polio virus  (type 1, LSc-2ab ). Here the combination of the three compo› nents exhibits a considerably greater virucidal action than the  individual components alone. Hence as regards virucidal  action there is a positive synergistic effect. In addition, it has  been found that with such disinfectants the reduction in the  viral strains by 4 log stages or 99.99% reduction in the viral  strains required in the aforesaid standard EN 14476 (2005)  can already be achieved from an exposure time of 1 minute.  With longer exposure times reductions of more than 5 log  stages or more than 99 .999% reductions in the viral strains are  possible.  [0031]  As already stated above, the polio virus type 1,  LSc-2ab is a very refractory and hard to inactivate virus, since  it is in particular highly resistant to chemicals, essentially  acid-stable and unaffected by lipid solvents ( e.g. ethers or  detergents). Since the disinfectants according to the invention  are capable of inactivating the polio virus type 1, LSc-2ab,  they are very probably also active against the vaccinia virus,  strain Elstree, the adenovirus type 5, strain adenoid 75 and the  polyoma virus (SV 40), strain 777.  [0032]  Furthermore, the disinfectants according to the  invention have also been found to be very well tolerated by the  skin. In particular through the synergistic action of the urea  with the acidic compound the concentrations of these two  components can be kept relatively low. Hence even with  regular use of the disinfectants according to the invention  over prolonged periods, skin reddening, itching, burning or  the like hardly ever occur. Furthermore, on account of the  composition of the disinfectant according to the invention, no  residues which are unpleasant or adversely affect the feel of  the skin remain on the skin.  [0033]  Since urea is contained in the natural moisture reten› tion factor of human skin, this is in principle compatible with  human skin and represents no fundamental health risk.  [0034]  In addition, the disinfectants according to the inven› tion are storage-stable and thus storable relatively problem› free. Precipitation of solids and/or changes in the chemical  composition or decomposition products are essentially unde› tectable even after several weeks. Hence there is practically  no risk that in practice decomposed and no longer sufficiently  effective disinfectants will be used or that undesired and in  any case harmful by-products will form in the disinfectant.  [0035]  The content of the alcoholic main component is  advantageously at least 50 wt. % and less than 80 wt. %. A  content of the alcoholic main component of at least 50 wt. %  and less than 80 wt. % guarantees a virucidal action for the  disinfectant, without the need for special precautionary mea› sures during transport, storage and use. The content of the  alcoholic main component is advantageously at least 60 wt.  %. However, the content of the alcoholic main component is  particularly preferably 65-75 wt. %.  DESCRIPTION OF THE INVENTION 