Standard classification for "heavy metal" testing in coatings

0 Foreword
widely used in coatings, but due to the complex composition of coatings, a variety of hazardous substances may be introduced in the production process. These substances are mainly toluene, xylene, toluene isocyanate, phthalates, ethylene glycol ether and ether ester compounds, but also some toxic and harmful heavy metal elements such as lead (Pb), mercury (Hg), cadmium (Cd, arsenic (As), chromium (Cr) and so on, these elements in the body will accumulate, not easy to excrete, more than a certain amount of human and animal toxic effects, causing tissue organ lesions or dysfunction, etc. , causing irreversible great damage to human health. In order to limit the content of these elements in coating products, the National Standardization Management Committee has developed a number of standards
china
. These standards include national and industry standards, product standards and method standards. The development of these standards has achieved positive significance in regulating the quality of coating products and conducting coating testing. However, due to the large number of these standards and different categories, the use of the process is prone to confusion. In this paper, the standards of heavy metal testing in the commonly used coating standards are listed and classified, and the contents of the test methods in the standard are summarized to facilitate the use of heavy metal testing engineers and technicians in coatings.1 Classification of standards according to the principle of testing
1.1 Principle of "soluble" heavy metal content testing
"Soluble" heavy metal content testing refers to the use of the same solution as the concentration of human stomach acid, generally made into 0.07 mol /L's solution of thin hydrochloric acid (pH: 1.12) treats the coating dry film (self-drying or drying), and then determines the content of the specified element by appropriate method, the essence of which is to separate the elements by extraction, so that the element under test dissolves in the acid solution.
1.1.1 Domestic standards for testing the content of "soluble" heavy metals in coatings
the earliest "soluble" heavy metal testing standards in China are GB9760-1988, which provides for the use of 0.07 mol/L hydrochloric acid extraction liquid or powdery paint. The standard was developed by using ISO6713-1984, which requires the addition of solvent centrifugation to the paint filler in the excellent paint, and the current use of "soluble" heavy metal content testing is not exactly the same, not applicable to dry coating film. At present, the paint standards for "soluble" heavy metal content testing standards are:
GB 18581
-2009 interior decoration material solvent-based wood coating harmful substances limit;
GB 18581-2001 Interior decoration materials Solvent-type wood coating harmful substances limit;
GB 18582-2001 interior decoration materials interior wall paint harmful substances limit;
GB 18584-2001 interior decoration materials wood furniture harmful substances limit;
GB 24613-2009 Limits of Harmful Substances in Toy Coatings; maximum limits of soluble elements in
GB 8771-2007 pencil coatings;
GB 6675-2003 National Toy Safety Technical Specifications;
GB/T 23446-2009 Spraying polypropyl waterproof coatings;
GB/T 23996-2009 solvent-based metal plate coatings for interior decoration;
GB/T 23994-2009 limits of specific harmful elements in coatings for consumer products in contact with the human body; and
GB/T 23991-2009 coatings for determining the content of "soluble" harmful elements. HJ/T 371-2007 Environmental Mark Product Technical Requirements Concave ink and soft-print ink;
HJ4 57-2009 Environmental Mark Product Technical Requirements Waterproof Coatings;
HJ/T 201-2005 Environmental Mark Product Technical Requirements Water-based Coatings;
HJ/T 414-2007 Environmental mark product technical requirements Solvent-based wood coating for interior decoration;
HG/T 3951-2007 building paint water-based color paste;
HG/T 2238-1991 F01-1 phenolic varnish;
JC 1066-2008 Limits of hazardous substances in building waterproof coatings;
JG/T 206-2007 Environmentally friendly silicone-propylene emulsion multi-layer coating for external insulation of exterior walls;
HG// T 3828-2006 indoor water-based wood coating;
HG/T 2006-2006 thermoso-solid powder coating;
JG/T 210-2007 Primer for interior and exterior walls of buildings; technical conditions for the coating of toy surfaces in
QB/T 2359-2008;
GB/T 9758.1-1988 determination of "soluble" metal content: part 1 of
: Spectroscopic spectroscopy of flame atom absorption of lead content and spectroscopicity of double sulfur
determination of the metal content of "soluble" in GB/T 9758.4-1988: Part 4: Measurement of cadmium content Flame atomic absorption spectroscopy and polar spectrometration;
GB/T 9758.6-1988 Determination of "soluble" metal content: Part 6: Measurement of the total content of chromium in the liquid part of the paint Flame atomic absorption spectroscopy;
GB/T 9758.5-198 8 Determination of "soluble" metal content: Part 5: Testing of hexavalent chromium content in pigment parts of liquid paint or powdered paint dibenzene carbabasin dialight;
GB/T 9758.7-1988 "solubility" Determination of metal content: Part 7: The determination of mercury content of pigment part of color paint and liquid part of water dilutable paint flameless atomic absorption spectroscopy;
GB/T 9758.2-1988 Determination of "soluble" metal content: Part 2: Determination of radon content Flame atom absorption spectroscopy and Jodamin B spectrophotomtation method
;
the most important thing to note in the method standard of "soluble" heavy metal testing is the mandatory standard GB 18581 and GB 18582, which requires element extraction at room temperature, which is different from the extraction temperature specified in GB 24410 of (37±2) degrees C. At the same time GB 18581-2001, GB 18582-2001 and GB 18581-2009, GB18582-2008 compared to the test results increased coefficient correction, from the prescribed use of AAS testing to the use of appropriate instrument testing, including ICP-OES can also be used.
1.1.2 International standards for testing "soluble" heavy metal elements in coatings
ISO 8124-3:2010 Toy Safety - Part 3: Transfer of certain elements, measure the transferable amount of 8 elements.
assTM F963-2011 toy safety standards to measure the amount of 8 elements that can be migrated.
C.R.C., C.931 Canada Dangerous Products (Toys) Regulations: The amount of migration involving seven elements: lead, mercury, vanadium, arsenic, vanadium, cadmium and selenium. Mercury cannot be detected in the sample, and the content of "soluble" palladium, arsenic, vanadium, cadmium and selenium is less than or equal to 0.1%. Unexpected "soluble" lead, the total lead value can not be greater than 600×10-6.
five "soluble" heavy metals were tested in book5-experimental rules and processes (2005-07-05) of the Product Safety Laboratory in Canada.
EN 71-3:2001/AC: 2002 Toy Safety - Part 3: Transfer of certain elements specifies the maximum limit of 8 transferable elements (vanadium, arsenic, vanadium, cadmium, chromium, lead, mercury, selenium) in the accessible parts or materials of the toy.
BS 5665: Part 3/BS EN 71-3 Transfer of Certain Elements (UK), DIN EN71-3 Transfer of Certain Elements (Germany), NF EN71-3 Transfer of Certain Elements (France), UK, Germany, France Toy Standard Technical Content is used in the EU toy standard EN71.
AS/NZS ISO 8124-3:2003 Migration of certain elements, AS/NZS ISO 8124 is a common toy standard in Australia and New Zealand, and the technical content is basically equivalent to the international toy standard ISO 8124.
ST 2002, the Japan Toy Association standard, specifies the limit value of the eight heavy metal elements in the surface coating of the toy material.
1935/2004/EC, the Food Contact Substances Act (EU), which tests the outer coating of food packaging and the amount of lead, cadmium and chromium in the coating.
international coating "soluble" heavy metal content testing standards are mainly for some close contact with people on the coating of heavy metal content testing, including toy coating, food packaging coating. The methods specified in the EN 71-3 standard are adopted or used by ISO as well as in many countries, and its contents are constantly being revised and updated. In EN 71-3 (1988), AAS (atomic absorption spectrometer) is required for assay, and in EN71-3 (1994,2000) standard, what type of instrument is not specified, only the instrument detection limit can reach 1/10 of the limit. EN 71-3 (1994, 2000) also provides for numerical correction of the test results of the eight elements after multiplying the correction factor. In the latest version of EN 71-3, 19 elements were detected: aluminum, vanadium, arsenic, vanadium, boron, cadmium, chromium (III.), chromium (VI.), cobalt, copper, lead, manganese, mercury, nickel, selenium, palladium, tin, organo tin, zinc, which will take effect on 21 July 2013.
1.2 Total heavy metal content test principle
Total heavy metal content test refers to the dry coating film, the use of appropriate pre-treatment methods will be tested elements into a suitable state for determination, and then the use of appropriate analytical instruments to determine the content of heavy metal elements in the post-treatment test solution.
1.2.1 Domestic standards for testing the total heavy metal content in coatings
GB 24409-2009 Limits of Hazardous Substances in Automotive Paints;
GB 24408-2009 Limits of Harmful Substances in Exterior Paints for Buildings;
GB 24613-2009 Limits of Harmful Substances in Toy Paints;
GB/T 6822-2007 Hull anti-fouling anti-rust paint system (organic tin anti-fouling content);
HG/T 2445-91 nitro pencil paint;
HG/T 2446-91 nitro pencil primer;
HG/T 3952-2007 electrodyswimming paint;
HJ/T 303-2006 Environmental Mark Product Technical Requirements Furniture;
GB/T 13452.1-1992 Color Paint and Varnish Total Lead Content Test;
GB/T 22788-2008 Toy Surface Coating Total Lead Content Determination;
SN/T 2792-2011 Determination of the migration of specific elements and total lead content in imported and exported furniture coatings.
1.2.2 International standards for testing the total heavy metal content in coatings
AsTM F963-2011 provides for the testing of total lead, the total lead content in the coating is less than 90×10-6.
U.S. Federal Regulations (16CFR 1303) stipulates that the total lead limit for coatings in furniture, toys, and other consumer goods shall not exceed 600×10-6, which was later changed to 90×10-6 by the CPSIA Directive.
standard implementation procedures for continuous analysis of lead content prepared with dry paint samples using ASTM E 1645-01 (2007) thermal plate or microwave dissolution.
standard operating procedures for determining lead in coatings and other similar surface coatings using CPSC-CH-E1003-09.1 (2011).
IEC62321:2008 (Ed 1.0) provides standard methods for testing lead, mercury, cadmium, hexavalent chromium, PBBs and PBDEs in electrical and electronic products.
2000/53/EC Technical Directive on End-of-Life Vehicles, issued by the European Parliament and Council on 18 September 2000, prohibits the use of materials containing heavy metals such as lead, mercury, cadmium and hexavalent chromium. 2 Classification of standards by content
2.1 Paint product standards for heavy metal testing
Toy coatings: GB 24613-2009 Limits of hazardous substances in toy coatings; QB/T 2359-2 008 Toy surface coating technical conditions, GB/T 23991-2009 paint "soluble" harmful elements content determination, GB/T 23994-2009 contact with the human body in the consumption products of the paint specific harmful elements limit.
automotive coatings: GB 24409-2009 automotive coatings in the limit of harmful substances.
wood coating: HJ/T 414-2007 environmental mark product technical requirements Interior decoration with solvent-based wood coating;
waterproof coatings: HJ 457-2009 environmental mark product technical requirements waterproof coatings; GB/T 23446-2009 spray polysacchargium waterproof coatings; JC 1066-2008 building waterproof coatings in the limit of harmful substances.
Powder Coatings: HG/T 2006-