Detailed explanation of registration of new chemical substances in polymers
According to the requirements of "New Chemical Material Environmental Management Registration Method" and "New Chemical Material Environmental Management Registration Guide", polymer, as a special type of polymer material, may cause lower hazards, and its registration conditions are different from those of general substances, and in most cases, there are different degrees of data reduction.
Starting from today, we will introduce a series of polymer registration details to analyze the requirements and processes of polymer registration. In this issue, we focus on introducing the basic concepts of polymers, registration strategies, analyzing the situation of polymer filing, and exclusion conditions.
Definition of polymer:
Polymer means that a substance molecule consists of one or more monomer units in sequence, and the molecular weight distribution of such molecules is within a certain range, and the difference of molecular weight mainly depends on the difference of the number of monomer units. The polymer shall meet the following three conditions:
(1) the molecular weight is not a certain fixed value, but presents a dispersed distribution;
(2) More than 50% (weight percentage) of the molecules contain at least three monomer units, which are connected with at least one other monomer unit or other reactants in the form of covalent bonds;
(3) Molecules with the same molecular weight shall not exceed 50% (weight percentage) of all molecules.
At the same time, substances meeting the above three conditions can be registered as new chemical substances according to the requirements of polymers. According to the nature of polymer, the possible registration types are filing, simple registration and routine registration, and the requirements of the three types of registration data are gradually increased. You can gradually judge according to the registration strategy and choose the appropriate registration type.
Polymer registration strategy:
Polymer filing situation
1. The annual production or import of new chemical substances is less than 1 ton;
Two, the new chemical monomer or reactant content is not more than 2% of the polymer or belongs to the low attention polymer.
For the first case, it is only necessary to meet the conditions that the annual production or import volume is less than 1 ton, and the requirements for filing materials are the same as those for general substances.
In the second case, the filing is only for polymers. In addition to meeting one of the two polymer conditions, polymers need not be excluded from the filing, and the annual production or import volume is not limited.
Requirements for polymer filing materials:
Record form of new chemical substances
Legal person certificate or business license, agency contract or agreement (with agent), power of attorney (with authorization)
Conformity with polymer record certification materials *:
A list of monomers/reactants
B molecular weight distribution diagram
C polymerization mechanism process
D, the application material does not belong to the discrimination and explanation materials of polymer record exclusion
Other information on environmental and health hazard characteristics and environmental risks that have been mastered
* According to the first case for the record, do not need to provide relevant documents.
Polymers meeting the second filing situation:
(1) The polymer itself is not in the List, but the weight percentage of all new chemical monomers/reactants of the polymer is less than or equal to 2%.
(2) The polymer itself is not in the List, but all monomers/reactants of the polymer are in the List.
Low concern polymer
(1) the number average molecular weight of the polymer is between 1,000 and 10,000. The content of oligomers with molecular weight less than 500 is less than 10%, and the content of oligomers with molecular weight less than 1,000 is less than 25%. At the same time, it shall not contain functional groups of high concern or high reactivity, such as heavy metals, cyano (except non-conjugated), acrylate, aziridine, isocyanate (except blocked isocyanate), thioisocyanate, vinyl sulfone, alkoxysilane (alkyl is methyl or ethyl), amine, spiroenamine, halosilane, hydrazine, α/β lactone, methacrylate, etc.
(2) The number average molecular weight of the polymer is greater than or equal to 10,000. The content of oligomers with molecular weight less than 500 is less than 2%, and the content of oligomers with molecular weight less than 1,000 is less than 5%.
(3) Polyester polymer: The main chain is a polymer in which monomers are bonded by ester bonds or a polymer in which the main chain is linked by ester bonds.
Exclusion of polymers:
Cationic polymers (such as polymers containing covalent bonds with phosphonium ions, sulfonium ions and ammonium ions), or polymers that are expected to become cationic polymers in natural water environment (polymers containing amino groups and isocyanates).
Degradable or unstable polymers, including polymers that are easy to degrade, decompose and depolymerize*, and polymers that decompose after production or use.
Water-absorbent polymer with number average molecular weight greater than or equal to 10,000 Daltons**.
Fluoropolymers with perfluoroalkyl sulfonic acid groups, perfluoroalkyl carboxylic acid groups or fluorine telomer structural fragments in their structures;
A fluoropolymer containing perfluoroalkyl structural fragments covalently bonded to carbon or sulfur atoms in the polymer molecule.
In addition to impurities, containing other elements than the following allowable elements:
Components of polymer must contain at least two elements of carbon, hydrogen, nitrogen, oxygen, sulfur or Silicon (c, h, n, o, s or si).
Additional elements: fluorine, chlorine, Bromine and iodine (f, Cl, br and I) covalently bonded to carbon, and chloride, bromide and iodide (Cl-
, Br- and I-).
Other allowed single ion elements are sodium, magnesium, aluminum, potassium and calcium (Na+, Mg+2, Al+3, K+ and Ca+2), and lithium, boron, phosphorus, titanium, manganese, iron, nickel, copper, zinc, tin and zirconium (Li, B, P)
*Degradation, decomposition, or depolymerization refers to chemical changes in which polymers are decomposed into simpler and smaller molecular weight substances by oxidation, hydrolysis, heat, light, solvents, or microorganisms.
**Water-absorbent polymers refer to polymers that can absorb their own weight of water, excluding water-soluble polymers and polymers that can be dispersed in water (including self-dispersed or dispersed).
In both cases, after submitting the data, they will receive the receipt automatically sent by the system, and they can start activities without waiting for the approval of the Ministry of Ecology and Environment. The registration materials that have been put on record will be randomly selected at the later stage of the solid management center, and scientific judgment is required when putting on record.
If polymers cannot be filed, simple registration or routine registration should be selected according to the activity volume. We will introduce the relevant requirements of simple and routine registration of polymers in the next issue.