|
|||||||||||||||||||
|
QUESTION:
Lead Content in Ceramic Glazes, 04 Nov 2005, New South Wales Australia Hello I am very happy to have found such an informative organisation alerting the public on the dangers of lead. I am trying to find out about lead content in ceramic glazes. There doesn't seem to be any enforceable govt standards or industry-wide standards. I have had trouble finding test kits or labs that do such a test. Although I'm aware that there is a test designed by Standards Australia for this purpose. How can I confidently test ceramic-ware ie tiles for a kitchen splashback or for food uses? best regards Dominik Kollar |
||||||||||||||||||
|
ANSWER: 22 Nov 2005 Dear Dominik, The National Health and Medical Research Council provides essential guidelines about “Lead Hazards from Pottery Glazes.” “Council considered that pottery utensils with glazes which release 7 ppm or more of lead, as determined by the ASTM method, C-555-71: Estimation of Lead Extracted from Glazed Ceramic Surfaces’, are unsafe for use as human food or drink containers.” (NHMRC, Pottery in Australia, Vol 13, No. 1, 1974) To test the content of lead in ceramics, you might want to use a home testing kit. You may then compare the results of the sample with the guidelines provided in the operating manual, or else use the guidelines used by professional lead inspectors, which I have provided you with in this email. Scanning Analysers for lead may be specially purchased at Palintest Australia www.palintest.com.au/lead_testing.htm. In particular, the PT 450 SA-4000 is a test specifically designed to target lead content in ceramic samples, and the kit comes with all the necessary equipment and instructions for testing various ceramic wares. You may wish to view this item’s specifics at www.palintest.com.au/literature/product%20flyer-SA4000.PDF. “Based on the established technique of differential pulse anodic stripping voltammetry, the instrument uses detachable disposable electrodes to simultaneously test for lead and cadmium in ceramic leachate. The leachate is prepared as specified by the Association of Official Analytical Chemists (ADAC) - a 24 hour soak of the vessel in 4% acetic acid. A 5 ml aliquot of the leachate is taken and a conditioning tablet is added to it. The sample is now ready for testing.” Professional lead inspectors and risk assessors abide by universally enforceable codes when analysing the content of lead in ceramics. The Department of Health, Massachusetts, document 105 CMR 460.000: LEAD POISONING PREVENTION AND CONTROL provides the following definition under 460.020 (page 3) for testing lead content: (B) When present in a dried film, including but not limited to paint, glaze, stain, varnish or other substance on any toy, furniture or other articles, or when present in paint, other coating, plaster or putty on residential surfaces, a dangerous level of lead shall be deemed to be the following: (1) a positive reaction with a 6% to 8% sodium sulfide solution, indicative of 0.5% or more lead by dry weight; or (2) equal to or more than 1.0 milligram of lead per square centimeter (mg/cm2) of surface as measured on site by a mobile x-ray fluorescence analyzer; or (3) equal to or more than 5,000 parts per million (ppm) or equal to or more than 0.5% by dry weight, as measured by atomic absorption spectrophotometry. (C) When present in a glaze or enamel on a glass, ceramic, porcelain or porcelain-coated cooking, eating or drinking utensil, or a porcelain-coated household appliance or fixture, a dangerous level of lead shall be deemed to be two parts per million or greater as tested by A.S.T.M. Standard Method C 738. (D) Grandfather Provision. Surfaces identified pursuant to the provisions of 105 CMR 460.730 prior to August 30, 2002 to contain a level of lead between 1.0 milligram and 1.2 milligrams per square centimeter, inclusive, shall be deemed not to contain a dangerous level of lead, provided such surfaces are maintained in an intact condition. www.mass.gov/Eeohhs2/docs/dph/environmental/lead/1054601.pdf #search='ceramictileleaddanger Analysis of your results will depend on whichever test kit and/or method you comparably use. The testing methods listed in the CMR are as follows: 460.740: Testing Methods : (A) Testing with X-Ray Fluorescence Analyzer. Lead inspectors shall operate the instrument in conformity with the manufacturer’s instructions and training and educational materials approved by the Director. The ins trument’s standardization must be verified at least once a day when the instrument is being operated, or more often if so specified by the manufacturer, and a logbook must be maintained of all readings made during standardization verification. (B) Testing with Six Percent to Eight Percent Sodium Sulfide Solution. Lead inspectors and code enforcement lead determination inspectors shall use sodium sulfide solution in conformity with instructions in training and educational materials approved by the Director. The formation of a gray or black color indicates a dangerous level of lead. If no color change to gray or black occurs within 30 seconds, the test result is negative for dangerous levels of lead. This test shall not be performed directly on iron or copper pipes, railings or radiators, or other metal surfaces. Labs that test ceramics for lead in Sydney: Non-destructive testing (i.e., ceramic sample is NOT destroyed in the testing process.) CTI Consultants, PO Box 153, Strathfield North, NSW 2137 phone: 9736 3911 Destructive testing: Institute of Clinical Pathology and Medical Research, PO Box 162, Lidcombe, NSW 1825 phone 9646 0424 Sydney Analytical Laboratories, 1 / 4 Abbott Rd, Seven Hills, NSW 2147 phone: 9838 8903 Australian Government Analytical Laboratories, 1 Suakin St, Pymble NSW 2073 phone 9449 0111 Domimik, I hope this answers your question. If you have any further queries, please get in touch. Josephine and Nathan Volunteer Information Officers, on behalf of Elizabeth O'Brien |
|||||||||||||||||||
| Back
to Q & A About Us Contact Us Council LEAD Project egroups Library / Fact Sheets Home Page Media Releases Newsletters Q & A Referral_lists Reports Site Map Slide Shows / Films Subscription Useful Links Search this Site Last Updated 31 January 2008
|
|||||||||||||||||||
