Nanotechnologies—Guidance on physico-chemical characterization of engineered nanoscale materials for toxicologic assessment
Some standard content:
ICS71.040.50
National Standard of the People's Republic of China
GB/T 39261—2020/IS0/TR 13014:2012Nanotechnologies-—Guidance on physico-chemical characterization of engineered nanoscale materials for toxicologic Assessment (IS0/TR13014:2012, IDT)
2020-11-19 Issued
State Administration for Market Regulation
National Administration of Standardization
2021-06-01 Implementation
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Terms and definitions
Abbreviations
General purpose of physicochemical characterization before toxicological assessment
Measurement results and uncertainties of physicochemical characterization parameters of nano-objects before toxicological assessment
Report:
Appendix A (informative)
GB/T 39261—2020/IS0/TR 13014:2012T
Graphical illustration Application of physicochemical property characterization in physical testing Appendix 13 (Informative Appendix) Determination methods and standard examples References
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This standard was drafted in accordance with the rules given in GB/T1.12009 GB/T39261—2020/1S0/TR13014:2012 This standard uses the translation method and is equivalent to IS0/TR13014:2012 "Guidelines for Characterization of Physical and Chemical Properties of Nanomaterials Before Toxicological Evaluation":
This standard has made the following editorial changes:
References have been reordered.
This standard was proposed by the Chinese Academy of Sciences.
This standard is under the jurisdiction of the National Technical Committee for Nanotechnology Standardization (SAC/TC279). Drafting unit of this standard: National Center for Nanoscience and Technology Main drafters of this standard: Ru, Chen Tunying. -rrKaeerkAca-
GB/T39261—2020/IS0/TR13014:2012 Introduction
In recent years, with the widespread application of nanomaterials in consumer and other products, people have become more and more concerned about the health and environmental problems that may be caused by exposure to nanomaterials, especially nano-objects and their aggregates and aggregates (NOAA). Although there have been a large number of physicochemical studies on NOAA, most of these studies did not provide detailed physicochemical characterization data, or did not evaluate and compare the test results obtained. Given that different NOAA have similar compositions, specific chemical characterization is the key to determine the material under study and is conducive to the improvement of the understanding of the toxicity of nanomaterials.
This guide provides guidance for the physicochemical characterization of commercial artificial nano-objects before toxicity assessment (including human and ecological assessment). The purpose of this guide is to assist scientists in other fields to understand, plan, identify and confirm the physical and chemical properties of these materials before conducting toxicological studies. This is a prerequisite for biological evaluation and is consistent with other ISO standards. For example, ISO1099318 conducts chemical characterization of materials used in medical devices, and ISO14971 points out that toxicological risk analysis needs to consider the chemical properties of materials. Physical and chemical property characterization can provide important information for better understanding the relationship between toxicological test results and physical and chemical properties. This guide provides the following valuable physical and chemical characterization information to facilitate subsequent toxicological evaluation: How physical and chemical characterization fits in with NOAA's physical testing process: Physical and chemical characterization is the key to physical testing; What parameters are included in physical and chemical characterization?
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1 Scope
Nanotechnology
GB/T39261—2020/IS0/TR13014:2012 Guidelines for Characterization of Physical and Chemical Properties of Nanomaterials before Toxicological Evaluation This standard provides guidance for characterizing the chemical properties of artificial nano-objects and aggregates and aggregates (NOAA) larger than 100 μm. The purpose is to help evaluate and clarify the impact of chemical properties on toxicological effects, and can also be used to distinguish between the material to be tested and similar materials. This standard provides a description, explanation, relevant properties, examples of measurements and test methods for each chemical property. This standard has reference value for researchers (such as toxicologists, ecotoxicologists, regulators, and health and safety experts) who are committed to studying the potential toxicological effects of NOAA. 2 Terms and definitions
IS0/TS27687||TS80004-1, IS0/TS80004-3, IS0/IEC Guide 99 and the following terms and definitions apply to this document.
aggregate
aggregate
a new particle composed of particles that are strongly bound or fused together, whose surface area is approximately the sum of the surface areas of the individual particles: Note 1: The forces that support the aggregate are strong forces, such as covalent bonds or due to sintering or complex physical bonding. Note 2: Aggregates are also called secondary particles, while the source particles are called primary particles. [1ISO/TS27687:2008, Definition 3.3
agglomerate
a collection of weakly bound particles, an aggregate, or a mixture of the two, whose surface area is approximately the sum of the surface areas of the individual particles. Note 1: The forces acting on aggregates are weak forces, such as van der Waals forces or simple physical entanglements. Note 2: Aggregates are also called secondary particles, while the source particles are called primary particles. [ISO/TS276872008 definition 3.2
carbon nanotube
carbon nanotube: CNT
nanotube composed of carbon atoms.
Note: usually a single layer of curled, including single-layer nanotubes and multi-layer nanotubes. ISO/TS800043:2010, definition 4.3
colloid
a multi-village material composed of nanoparticles (11 to 1001 μm) uniformly floating in a liquid (dispersion medium) by the action of electricity, these particles show Brownian motion and electrophoresis. Note 1: has the properties of colloids.
Note 2: Rewrite ISO 1942-2
composition
The properties of nanomaterials are determined by the characteristics and composition of each specific component. Note: Rewrite IS06111.
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GB/T392612020/IS0/TR13014:20122.6
crystallinity
Crystallinity
Three-dimensional spatial structure at the molecular level.
LISO 472]
Combined standard measurement uncertainty combined standard measurement uncertainty combined standard uncertainty (deprecated) In a measurement model, the standard measurement uncertainty is obtained by calculating the individual standard measurement uncertainties associated with the input quantities. Note: If there is a correlation between the input quantities in the measurement model, the covariance must be taken into account when calculating the combined standard measurement uncertainty. See 2.3.4.S0/IECGuide99.2007 of ISO/IEC Guide 88-3: 2008, definition 2.3 [2.8
dispersibility
dispensahility
The degree of dispersion that forms a stable system under given conditions. Note 1: Dispersion refers to the suspension state of discrete particles. Note 2: Rewrite IS) 87801 and IS) 12131. 2.9
expanded measurement uncertainty
Expanded uncertaintyexpancleduncertainty means the product of the standard measurement uncertainty and a factor greater than 1. Note 1: This factor depends on the type of probability distribution output in the measurement model and the chosen range of probabilities. Note 2: In this definition, the term "factor" refers to the range factor. The range factor is a constant that is multiplied by the standard measurement uncertainty of the measurement result to give the expanded measurement uncertainty.
Note 3: Modified from ISO/IHC Guide 99
fullerene
Fullerene
A molecule consisting of a pseudo-number of carbon atoms, with a closed cage structure consisting of a polycyclic system of fused rings, of which C60 has 12 five-membered rings and the rest are hexacyclic rings.
Note 1: Adapted from the definition in the International Union of Pure and Applied Chemistry (IUIPAC) Compendium of Chemical Terminology. NOTE 2 C60, as it is commonly known, is spherical with an outer dimension of approximately 111:1S0/TS80004-8, definition 8.1
measurement modelmeasurementmodel
a mathematical relationship between all known variables in a measurementNote 1: A measurement model is usually an equation (Y, Y, X) where the output quantity Y is derived from the measurand input quantities X, Y. NOTE 2: Adapted from ISO/IEC Guide 89.
traceability
metrological lraceahility
the property of a measurement result being related to a reference standard by an unbroken chain of calibrations with stated uncertainties. NOTE 1: For this definition: "reference standard" may refer to a measurement unit or a measurement process (including non-ordinal quantities), or a measurement standard. Note 2: The measurement source must establish a calibration level sequence. Note 3: Rewrite ISO/IEC Guide $9,
To be measured
measurand
as a specific variable of the measurement object.
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GB/T39261—2020/1S0/TR13014:2012 Note 1: To be measured, the category of the measurement object needs to be determined, and the state of the phenomenon, individual or intercepted material is described, including related components, chemicals, etc. NOTE 2: In the first edition of VIM and IEC 60:050-309:201, the measurand is defined as the quantity to be measured. NOTE 3: Measurement, including the conditions of the measuring system, may cause some phenomenon, object or substance to change so that the quantity being measured does not return to the intended measurand. Therefore, appropriate correction is required. NOTE 4: In chemistry, "analyte", or the name of the material or compound, is sometimes used as the term for the measurand. This usage is incorrect because these terms do not refer to dimensions. NOTE 5: For more information, see Ref. 70], NOTE 6: Rewrite ISO/IECGuide$9
Nanofibre
nanofibre
Nanofibre with two dimensions similar in size and in the nanometer scale, and the remaining dimension significantly larger than the other two dimensions:
Note 1: Nanofibres can be flexible or rigid. Note 2: For two dimensions with similar sizes, the difference in their external dimensions must be less than 3 times, and the longest external dimension must be 3 times larger than the other two dimensions. Note 3: The longest external dimension may not be in the nanometer scale. [ISO/TS 27687:2008.Definition 4.3-2.15
nanomanufacturing
Nanomanufacturing
The synthesis, production or manipulation of nanomaterials for commercial purposes, or the use of manufacturing steps in the nanometer range. LIS0/TS80004-1:2010.Definition 2.112.16
Fnanomaterial
Nanomaterial
Material with at least one dimension at the nanometer scale, or with an internal or external structure of the nanometer scale. Note 1: This is a general term that includes nano-objects and materials with nanostructures. Note 2: Rewrite 150/1S 80004-1
nano-object
nano-object
object with one, two or three external dimensions in the nanometer scale. Note: General technical terms for all separated nanometer-scale objects ISO/TS80004-1:2010, definition 2.52.18
nanoparticle
nanoparticle
nano-object with three external dimensions in the nanometer scale. Note: When the length of the longest axis of a nano-object differs significantly (more than 3 times) from the short axis, nanoparticles and nanosheets are used to represent nanoparticles [IS0/TS 27687:2008. Definition 4.12.19
nanoplate
nanoobject with one external dimension in the nanometer scale and two external dimensions significantly larger than the smallest dimension, Note 1: The smaller external dimension is the original dimension of the nanoplate Note 2: Significantly larger means more than 3 times larger
Note 3: The larger external dimension is not necessarily in the nanometer scale [ISO/TS80004-3.2010. Definition 4.2] 2.20
nanoscale
nanoscale
is in the size range between 1nm and 100mm. - rKaeerkca-
GB/T39261—2020/IS0/TR13014:2012 Note 1: This size range is used generally but exclusively to exhibit properties that cannot be extrapolated from larger sizes. For these properties, the lower limit is approximate.
Note 2: The lower limit (about 1 nm) is introduced in this definition to avoid that a single or small cluster of atoms is assumed to be a nano-object or nano-structure unit when no lower limit is set.
[IS0/TS80004-12010, definition 2.1] 2.21
Nanostructured material
nanostruciured material
Material with nanostructures inside or on the surface. Note: This definition does not exclude the possibility that a nano-object has internal or surface structures. If the external component(s) is on the nanometer scale, it is recommended to use the term "nano-object".
[IS0/TS80004-12010, definition 2.1] 2.21
Nanostructured material
nanostruciured material
Material with nanostructures inside or on the surface. Note: This definition does not exclude the possibility that a nano-object has internal or surface structures. If the external component(s) is on the nanometer scale, it is recommended to use the term "nano-object". 80004-[:20[0, definition 2.7]2.22
Nanotechnology
nanotechnology
The application of scientific knowledge to manipulate and control matter at the nanometer scale to exploit size- and structure-dependent properties and phenomena that differ significantly from those of individual elements, components or bulk materials. Note: Manipulation and control include materials synthesis, [ISO/TS80004-1:2010, definition 2.3]2.23
Nanotubenanotube
Hollow nano-dimensions,
[ISO/TS27687:2008. definition 4.4]
Particle sizebzxz.net
particle size
Size of a spherical particle with the same physical properties as the particle being measured Note 1: See equivalent particle diameter,
Note 2: There is no separate definition of particle size at present. Different physical properties measured require different analytical methods. In order to explain the physical properties involved in the equivalent diameter, it is usually necessary to use a subscript or mark the literature containing the relevant standard reference measurement method to explain the measured particle size results. In ISO) 9276, the symbol represents particle size or spherical diameter. However, the symbol d is also commonly used to represent these values. Therefore, when "appears, it can no longer be a river.
1S02150]-[:2009.Definition 2.3
Particle size distribution
particle size distribution
particle concentration accumulated by particle size.[1S0 14641-6;2007,Definition 2.107]2.26
Particle shape
particle:shape
The geometric shape of a particle:
Note: Modified from ISO3252
Solubility
Solubility
The maximum mass of a nanomaterial that can be dissolved in a given volume of solvent under given conditions. Note 1: Solubility is expressed as grams per liter of solvent
Note 2: Modified from IS) 7570
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Surface area
surface area
The sum of the outer surface area and the inner area of the pores in contact with the surface. Note: It includes mass specific surface area or volume specific surface area. 2.29
Surface charge
surface charge
The charge on the surface of an object.
surface chemistry
Surface chemistry
The chemical properties of the surface.
validation
Verification according to the requirements corresponding to the intended use. Note: Modified ISO/IEC Guide 99
Verification verification
Provide objective evidence to prove that a specific item meets certain requirements. Note 1: In application, measurement uncertainty must be considered. Note 2: Verification may be a process, measurement step, material, compound or measurement system. Note 3: Rewrite ISO/IEC Guide
3 Abbreviations
The following abbreviations apply to this document
GB/T 39261—2020/IS0/TR13014:2012 ADME Absorption, Distribution, Metabolism and Excretion AFM: Atomic Force Microscopy BIPM: Bureau International des Poids et Mesures CNT: Carbon Nanotube EHS: Environment, Health and Safety GMP: Good Manufacturing Practices GUM: Guide to the Measurement Uncertainty OECD: Organization for Economic Cooperation and Development DcvelopmcntNOAA: Nano-objects and their aggregations and aggregates larger than lo0nm nm)SEM: Scanning Electron Microscopy SPM: Scanning Probe Microscopy TEM: Transmission Electron Microscopy UV: Ultraviolet
4 Importance of Characterization of Physical and Chemical Properties Before Toxicological Assessment 4.1 Purpose of Toxicological Tests
Before commercializing new materials, risk assessment is required. According to the properties of the materials, physical and eco-physical evaluations are conducted to evaluate the potential effects of new materials on humans and the environment. Toxicological tests are used to evaluate the potential effects of chemical substances, including N)AA, on humans and the environment. The toxicity risk of a substance depends on its ability to produce toxic effects on organisms and the exposure dose. : Reasonable design of toxicological tests helps reduce the uncertainty of test results. The purpose of all toxicological tests is to obtain reliable information, including: - dose effect: different effects related to the intrinsic properties of the substance; - different effects related to different exposure routes; - type and severity of adverse effects; - mode and mechanism of action (including upstream biochemical mechanisms); - exposure during the susceptible period of the organism (such as fetal development); - carcinogenicity, mutagenicity and teratogenicity; - time course of response; - use of control groups, 4.2 General methods for toxicological testing and risk assessment 4.2.1 Overview
The potential risk and safety of materials to the human population and the environment are evaluated through the physical risk assessment method. As described in the Federal Government Risk Assessment: A Process Management Practice published by the National Research Council in 1983, risk assessment includes four steps: 1) hazard identification;
2) dose-effect/concentration-effect assessment: 3) exposure assessment;
4) risk characterization01.
Toxicology testing provides basic data for hazard identification, dose-effect assessment and exposure assessment. Through risk assessment, exposure estimates for occupational groups, the public or consumers can be obtained, personal protective equipment can be recommended, and hazard notification regulations can be compiled. 4.2.2 Hazard Identification
Hazard identification is the first step in risk assessment: it is used to determine whether a chemical substance can cause toxic effects. Relevant data are generally obtained through in vitro tests, in vitro tests, epidemiological surveys and human clinical studies. The test methods are repeatable and reproducible, so it is recommended to use standardized toxicology test methods.
Recently, based on ethical considerations, the academic community recommends the use of improved in vitro tests (exposing the materials to be tested to simple biological objects, such as viruses, tissue culture, and biopsy) and computer simulations to replace traditional in vivo tests (including experimental animals). This can reduce the use of animals and obtain relevant mechanism information (such as chemical cascade reaction processes or events). Examples of in vitro studies are the mechanisms by which chemicals bind to cell membrane receptors (e.g., lock-and-key models), how they stimulate signaling pathways and interact with cellular components: In addition, in vitro study results can also be used to design in vivo tests, where the ability of materials to cause effects (both expected and unexpected) can be related to their specific physicochemical properties, including impurities. However, obtaining information on their physicochemical properties is a prerequisite for effective toxicology testing. Based on accurate data on chemical properties, researchers can clearly characterize and describe NOAA, thereby identifying the same material, testing it with the same method, and ultimately obtaining repeatable physicochemical results. 4.2.3 Dose-effect assessment
Dose-effect assessment is the second step in the risk assessment process, which is used to examine the relationship between exposure and test system response (such as negative effects), and to clarify the relationship between material exposure dose and negative effects on exposed populations (environment): the assessment should take into account health conditions, age, gender, sensitivity or susceptibility related to population (environment) exposure, material size, intrinsic properties, variability and other modifying factors, as well as exposure dose, 6
-riKacerKAca-Bureau International des Poids et Mesures CNT: Carbon Nanotube EHS: Environment, Health and Safety GMP: Good Manufacturing Practices GUM: Guide to the Uncertainty of Measurement OECD: Organization for Economic Cooperation and Development NOAA: Nano-objects and their Aggregates and Agglomcrates larger than 100 nm nm)SEM: Scanning Electron Microscopy SPM: Scanning Probe Microscopy TEM: Transmission Electron Microscopy UV: Ultraviolet
4 Importance of Characterization of Physical and Chemical Properties Before Toxicological Assessment 4.1 Purpose of Toxicological Tests
Before commercializing new materials, risk assessment is required. According to the properties of the materials, physical and eco-physical evaluations are conducted to evaluate the potential effects of new materials on humans and the environment. Toxicological tests are used to evaluate the potential effects of chemical substances, including N)AA, on humans and the environment. The toxicity risk of a substance depends on its ability to produce toxic effects on organisms and the exposure dose. : Reasonable design of toxicological tests helps reduce the uncertainty of test results. The purpose of all toxicological tests is to obtain reliable information, including: - dose effect: different effects related to the intrinsic properties of the substance; - different effects related to different exposure routes; - type and severity of adverse effects; - mode and mechanism of action (including upstream biochemical mechanisms); - exposure during the susceptible period of the organism (such as fetal development); - carcinogenicity, mutagenicity and teratogenicity; - time course of response; - use of control groups, 4.2 General methods for toxicological testing and risk assessment 4.2.1 Overview
The potential risk and safety of materials to the human population and the environment are evaluated through the physical risk assessment method. As described in the Federal Government Risk Assessment: A Process Management Practice published by the National Research Council in 1983, risk assessment includes four steps: 1) hazard identification;
2) dose-effect/concentration-effect assessment: 3) exposure assessment;
4) risk characterization01.
Toxicology testing provides basic data for hazard identification, dose-effect assessment and exposure assessment. Through risk assessment, exposure estimates for occupational groups, the public or consumers can be obtained, personal protective equipment can be recommended, and hazard notification regulations can be compiled. 4.2.2 Hazard Identification
Hazard identification is the first step in risk assessment: it is used to determine whether a chemical substance can cause toxic effects. Relevant data are generally obtained through in vitro tests, in vitro tests, epidemiological surveys and human clinical studies. The test methods are repeatable and reproducible, so it is recommended to use standardized toxicology test methods.
Recently, based on ethical considerations, the academic community recommends the use of improved in vitro tests (exposing the materials to be tested to simple biological objects, such as viruses, tissue culture, and biopsy) and computer simulations to replace traditional in vivo tests (including experimental animals). This can reduce the use of animals and obtain relevant mechanism information (such as chemical cascade reaction processes or events). Examples of in vitro studies are the mechanisms by which chemicals bind to cell membrane receptors (e.g., lock-and-key models), how they stimulate signaling pathways and interact with cellular components: In addition, in vitro study results can also be used to design in vivo tests, where the ability of materials to cause effects (both expected and unexpected) can be related to their specific physicochemical properties, including impurities. However, obtaining information on their physicochemical properties is a prerequisite for effective toxicology testing. Based on accurate data on chemical properties, researchers can clearly characterize and describe NOAA, thereby identifying the same material, testing it with the same method, and ultimately obtaining repeatable physicochemical results. 4.2.3 Dose-effect assessment
Dose-effect assessment is the second step in the risk assessment process, which is used to examine the relationship between exposure and test system response (such as negative effects), and to clarify the relationship between material exposure dose and negative effects on exposed populations (environment): the assessment should take into account health conditions, age, gender, sensitivity or susceptibility related to population (environment) exposure, material size, intrinsic properties, variability and other modifying factors, as well as exposure dose, 6
-riKacerKAca-Bureau International des Poids et Mesures CNT: Carbon Nanotube EHS: Environment, Health and Safety GMP: Good Manufacturing Practices GUM: Guide to the Uncertainty of Measurement OECD: Organization for Economic Cooperation and Development NOAA: Nano-objects and their Aggregates and Agglomcrates larger than 100 nm nm)SEM: Scanning Electron Microscopy SPM: Scanning Probe Microscopy TEM: Transmission Electron Microscopy UV: Ultraviolet
4 Importance of Characterization of Physical and Chemical Properties Before Toxicological Assessment 4.1 Purpose of Toxicological Tests
Before commercializing new materials, risk assessment is required. According to the properties of the materials, physical and eco-physical evaluations are conducted to evaluate the potential effects of new materials on humans and the environment. Toxicological tests are used to evaluate the potential effects of chemical substances, including N)AA, on humans and the environment. The toxicity risk of a substance depends on its ability to produce toxic effects on organisms and the exposure dose. : Reasonable design of toxicological tests helps reduce the uncertainty of test results. The purpose of all toxicological tests is to obtain reliable information, including: - dose effect: different effects related to the intrinsic properties of the substance; - different effects related to different exposure routes; - type and severity of adverse effects; - mode and mechanism of action (including upstream biochemical mechanisms); - exposure during the susceptible period of the organism (such as fetal development); - carcinogenicity, mutagenicity and teratogenicity; - time course of response; - use of control groups, 4.2 General methods for toxicological testing and risk assessment 4.2.1 Overview
The potential risk and safety of materials to the human population and the environment are evaluated through the physical risk assessment method. As described in the Federal Government Risk Assessment: A Process Management Method published by the National Research Council in 1983, risk assessment includes four steps: 1) hazard identification;
2) dose-effect/concentration-effect assessment: 3) exposure assessment;
4) risk characterization01.
Toxicology testing provides basic data for hazard identification, dose-effect assessment and exposure assessment. Through risk assessment, exposure estimates for occupational groups, the public or consumers can be obtained, personal protective equipment can be recommended, and hazard notification regulations can be compiled. 4.2.2 Hazard Identification
Hazard identification is the first step in risk assessment: it is used to determine whether a chemical substance can cause toxic effects. Relevant data are generally obtained through in vitro tests, in vitro tests, epidemiological surveys and human clinical studies. The test methods are repeatable and reproducible, so it is recommended to use standardized toxicology test methods.
Recently, based on ethical considerations, the academic community recommends the use of improved in vitro tests (exposing the materials to be tested to simple biological objects, such as viruses, tissue culture, and biopsy) and computer simulations to replace traditional in vivo tests (including experimental animals). This can reduce the use of animals and obtain relevant mechanism information (such as chemical cascade reaction processes or events). Examples of in vitro studies are the mechanisms by which chemicals bind to cell membrane receptors (e.g., the lock-and-key model), and how they stimulate signaling pathways and interact with cellular components: In addition, in vitro study results can also be used to design in vivo tests, where the ability of materials to cause effects (both expected and unexpected) can be related to their specific physicochemical properties, including impurities. However, obtaining information on their physicochemical properties is a prerequisite for effective toxicology testing. Based on accurate data on chemical properties, researchers can clearly characterize and describe NOAA, thereby identifying the same material, testing it with the same method, and ultimately obtaining repeatable physicochemical results. 4.2.3 Dose-effect assessment
Dose-effect assessment is the second step in the risk assessment process, which is used to examine the relationship between exposure and test system response (such as negative effects), and to clarify the relationship between material exposure dose and negative effects on exposed populations (environment): the assessment should take into account health conditions, age, gender, sensitivity or susceptibility related to population (environment) exposure, material size, intrinsic properties, variability and other modifying factors, as well as exposure dose, 6
-riKacerKAca-Improved in vitro tests (exposing the material to be tested to simple agents such as viruses, tissue culture, biopsies) and computer simulations are recommended to replace traditional in vivo tests (including experimental animals). This can reduce the number of animals used and can obtain relevant mechanistic information (such as chemical cascade reaction processes or events). An example of in vitro research is the mechanism by which chemicals bind to cell membrane receptors (such as the lock and key model), and how signaling pathways are stimulated and interact with cellular components: In addition, the results of in vitro studies can also be used to design in vivo tests, and the effects (expected and unexpected) caused by the material itself can be related to its specific physicochemical properties, including impurities. However, obtaining information on its physicochemical properties is a prerequisite for effective toxicology testing. Based on accurate chemical property data, researchers can clearly characterize and describe NOAA, thereby identifying the same material, testing it with the same method, and ultimately obtaining repeatable physicochemical results. 4.2.3 Dose-effect assessment
Dose-effect assessment is the second step in the risk assessment process, which is used to examine the relationship between exposure and test system response (such as negative effects), and to clarify the relationship between material exposure dose and negative effects on exposed populations (environment): the assessment should take into account health conditions, age, gender, sensitivity or susceptibility related to population (environment) exposure, material size, intrinsic properties, variability and other modifying factors, as well as exposure dose, 6
-riKacerKAca-Improved in vitro tests (exposing the material to be tested to simple agents such as viruses, tissue culture, biopsies) and computer simulations are recommended to replace traditional in vivo tests (including experimental animals). This can reduce the number of animals used and can obtain relevant mechanistic information (such as chemical cascade reaction processes or events). An example of in vitro research is the mechanism by which chemicals bind to cell membrane receptors (such as the lock and key model), and how signaling pathways are stimulated and interact with cellular components: In addition, the results of in vitro studies can also be used to design in vivo tests, and the effects (expected and unexpected) caused by the material itself can be related to its specific physicochemical properties, including impurities. However, obtaining information on its physicochemical properties is a prerequisite for effective toxicology testing. Based on accurate chemical property data, researchers can clearly characterize and describe NOAA, thereby identifying the same material, testing it with the same method, and ultimately obtaining repeatable physicochemical results. 4.2.3 Dose-effect assessment
Dose-effect assessment is the second step in the risk assessment process, which is used to examine the relationship between exposure and test system response (such as negative effects), and to clarify the relationship between material exposure dose and negative effects on exposed populations (environment): the assessment should take into account health conditions, age, gender, sensitivity or susceptibility related to population (environment) exposure, material size, intrinsic properties, variability and other modifying factors, as well as exposure dose, 6
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