Note(s) [2009.01]

• In section C, the definitions of groups of chemical elements are as follows:
  • Alkali metals: Li, Na, K, Rb, Cs, Fr
  • Alkaline earth metals: Ca, Sr, Ba, Ra
  • Lanthanides: elements with atomic numbers 57 to 71 inclusive
  • Rare earths: Sc, Y, Lanthanides
  • Actinides: elements with atomic numbers 89 to 103 inclusive
  • Refractory metals: Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W
  • Halogens: F, Cl, Br, I, At
  • Noble gases: He, Ne, Ar, Kr, Xe, Rn
  • Platinum group: Os, Ir, Pt, Ru, Rh, Pd
  • Noble metals: Ag, Au, Platinum group
  • Light metals: alkali metals, alkaline earth metals, Be, Al, Mg
  • Heavy metals: metals other than light metals
  • Iron group: Fe, Co, Ni
  • Non-metals: H, B, C, Si, N, P, O, S, Se, Te, noble gases, halogens
  • Metals: elements other than non-metals
  • Transition elements: elements with atomic numbers 21 to 30 inclusive, 39 to 48 inclusive, 57 to 80 inclusive, 89 upwards
• Section C covers :
  • pure chemistry, which covers inorganic compounds, organic compounds, macromolecular compounds, and their methods of preparation;
  • applied chemistry, which covers compositions containing the above compounds, such as: glass, ceramics, fertilisers, plastics compositions, paints, products of the petroleum industry. It also covers certain compositions on account of their having particular properties rendering them suitable for certain purposes, as in the case of explosives, dyestuffs, adhesives, lubricants, and detergents;
  • certain marginal industries, such as the manufacture of coke and of solid or gaseous fuels, the production and refining of oils, fats and waxes, the fermentation industry (e.g., brewing and wine-making), the sugar industry;
  • certain operations or treatments, which are either purely mechanical, e.g., the mechanical treatment of leather and skins, or partly mechanical, e.g., the treatment of water or the prevention of corrosion in general;
  • metallurgy, ferrous or non-ferrous alloys.
• In all sections of the IPC, in the absence of an indication to the contrary, the Periodic System of chemical elements referred to is the one with 18 groups as represented in the table below.
  • 
• • In the case of operations, treatments, products or articles having both a chemical and a non-chemical part or aspect, the general rule is that the chemical part or aspect is covered by section C.
  • In some of these cases, the chemical part or aspect brings with it a non-chemical one, even though purely mechanical, because this latter aspect either is essential to the operation or treatment or constitutes an important element thereof. It has seemed, in fact, more logical not to dissociate the different parts or aspects of a coherent whole. This is the case for applied chemistry and for the industries, operations and treatments mentioned in Notes (1)(c), (d) and (e). For example, furnaces peculiar to the manufacture of glass are covered by class C03 and not by class F27.
  • There are, however, some exceptions in which the mechanical (or non-chemical) aspect carries with it the chemical aspect, for example:
    • Certain extractive processes, in subclass A61K;
    • The chemical purification of air, in subclass A61L;
    • Chemical methods of fire-fighting, in subclass A62D;
    • Chemical processes and apparatus, in class B01;
    • Impregnation of wood, in subclass B27K;
    • Chemical methods of analysis or testing, in subclass G01N;
    • Photographic materials and processes, in class G03, and, generally, the chemical treatment of textiles and the production of cellulose or paper, in section D.
  • In still other cases, the pure chemical aspect is covered by section C and the applied chemical aspect by another section, such as A, B or F, e.g., the use of a substance or composition for:
    • treatment of plants or animals, covered by subclass A01N;
    • foodstuffs, covered by class A23;
    • ammunition or explosives, covered by class F42.
  • When the chemical and mechanical aspects are so closely interlocked that a neat and simple division is not possible, or when certain mechanical processes follow as a natural or logical continuation of a chemical treatment, section C may cover, in addition to the chemical aspect, a part only of the mechanical aspect, e.g., after-treatment of artificial stone, covered by class C04. In this latter case, a note or a reference is usually given to make the position clear, even if sometimes the division is rather arbitrary.

Note(s) [2012.01]

• This class does not cover the following macromolecular compounds per se:
  • peptides, e.g. proteins, which are covered by subclass C07K;
  • compounds containing two or more mononucleotide units having separate phosphate or polyphosphate groups linked by saccharide radicals of nucleoside groups, e.g. nucleic acids, which are covered by group C07H 21/00;
  • DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification, which are covered by group C12N 15/00.
• Biocidal, pest repellant, pest attractant or plant growth regulatory activity of compounds or preparations is further classified in subclass A01P.

Note(s) [7]

• Therapeutic activity of compounds is further classified in subclass A61P.

Note(s) [7]

• In this subclass, boron or silicon are considered as metals.
• In this subclass, the following expression is used with the meaning indicated:
  • "aliphatic radical" means an acyclic or a non-aromatic carbocyclic carbon skeleton which is considered to be terminated by every bond to:
    • an element other than carbon;
    • a carbon atom having a double bond to one atom other than carbon;
    • an aromatic carbocyclic ring or a heterocyclic ring.

    Examples: Polymers of

    • CH₂ =CH—O—CH₂-CH₂ —NH—COO—CH₂-CH₂ —OH are classified in group C08F 16/28;
    • are classified in group C08F 16/36;
    • are classified in group C08F 12/18.

• Therapeutic activity of compounds is further classified in subclass A61P.
• In this subclass, the last place priority rule is applied, i.e. at each hierarchical level, in the absence of an indication to the contrary, a catalyst or a polymer is classified in the last appropriate place.
• In this subclass:
  • macromolecular compounds and their preparation are classified in the groups for the type of compound prepared. General processes for the preparation of macromolecular compounds according to more than one main group are classified in the groups for the processes employed ( C08F 2/00-C08F 8/00). Processes for the preparation of macromolecular compounds are also classified in the groups for the types of reactions employed, if of interest;
  • subject matter relating to both homopolymers and copolymers is classified in groups C08F 10/00-C08F 38/00;
  • subject matter limited to homopolymers is classified only in groups C08F 110/00-C08F 138/00;
  • subject matter limited to copolymers is classified only in groups C08F 210/00-C08F 246/00;
  • in groups C08F 210/00-C08F 238/00, in the absence of an indication to the contrary, a copolymer is classified according to the major monomeric component.
• This subclass covers also compositions based on monomers which form macromolecular compounds classifiable in this subclass (paints C09D 4/00; adhesives C09J 4/00).
  • In this subclass:
    • if the monomers are defined, classification is made according to the polymer to be formed:
      • in groups C08F 10/00-C08F 246/00 if no preformed polymer is present;
      • in groups C08F 251/00-C08F 291/00 if a preformed polymer is present, considering the reaction to take place as a graft or cross-linking reaction;
    • if the presence of compounding ingredients is of interest, classification is made in group C08F 2/44 (sensitising agents C08F 2/50; catalysts C08F 4/00);
    • if the compounding ingredients are of interest per se, classification is also made in subclass C08K.

Note(s) [7]

• Therapeutic activity of compounds is further classified in subclass A61P.
• In this subclass, group C08G 18/00 takes precedence over the other groups. A further classification is given if the polymers are obtained by reactions forming specific linkages for which an appropriate group is provided.
• Within each main group of this subclass, the last place priority rule is applied, i.e. at each hierarchical level, in the absence of an indication to the contrary, classification is made in the last appropriate place.
• This subclass covers also compositions based on monomers which form macromolecular compounds classifiable in this subclass.
  • In this subclass:
    • if the monomers are defined, classification is made in groups C08G 2/00-C08G 79/00, C08G 83/00 according to the polymer to be formed;
    • if the monomers are defined in a way that a composition cannot be classified within one main group of this subclass, the composition is classified in group C08G 85/00;
    • if the compounding ingredients are of interest per se, classification is also made in subclass C08K.

Note(s) [2006.01]

• In this subclass, the following term is used with the meaning indicated:
  • "rubber" includes:
    • natural or conjugated diene rubbers;
    • rubber in general (for a specific rubber, other than a natural rubber or a conjugated diene rubber, see the group provided for compositions of such macromolecular compounds).
• In this subclass:
  • compositions are classified according to the mutual proportions by weight of only the macromolecular constituents;
  • compositions are classified according to the macromolecular constituent or constituents present in the highest proportion; if all these constituents are present in equal proportions the composition is classified according to each of these constituents.
• Any macromolecular constituent of a composition which is not identified by the classification according to Note (2) above, and the use of which is determined to be novel and non-obvious, must also be classified in this subclass. For example, a composition containing 80 parts polyethene and 20 parts polyvinyl chloride is classified in both groups C08L 23/06 and C08L 27/06, if the use of polyvinyl chloride is determined to be novel and non-obvious.
• Any macromolecular constituent of a composition which is not identified by the classification according to Notes (2) or (3) above, and which is considered to represent information of interest for search, may also be classified in this subclass. This can, for example, be the case when it is considered of interest to enable searching of compositions using a combination of classification symbols. Such non-obligatory classification should be given as "additional information".