Guidelines for Specifications of Biochars for Use in Soils FINAL ...

12345678910111213141516171819204.2 Test Categories B and C – Basic and Supplemental Toxin ReportingIn addition to Test Category A thresholds and declarations, all biochar materials must meet thebasic soil toxicity assessment thresholds of Test Category B as outlined in Table 2 below.Category B tests are sufficient to assess the toxin risk of biochar made from unprocessedfeedstocks. Biochar made from processed feedstocks may carry additional risks from thepotential presence of toxins in the feedstock and must meet both Test Category B and TestCategory C threshold requirements given in Table 3 below.Biochar toxicity assessment reporting follows commonly identified soil toxicity and chemicalcontent reporting requirements for soil amendments, composts and fertilizers. The thresholdvalues in Tables 2 and 3 are given as a range of values based on regulatory requirements forsoil amendments or fertilizers from a number of countries. 1 The Maximum Allowed Thresholds(MAT) indicate toxin levels above which the material would not be considered acceptable. Inorder to meet the requirements of these Biochar Guidelines, reported toxin levels must bebelow the MAT, and must specifically be below thresholds established in countries wherebiochar is produced and/or intended for use. If the country where the biochar will be used hasa less stringent threshold or no threshold at all for a particular toxin, the biochar must be belowthe highest maximum value provided below for each specific toxin. See Appendix 3, RegulatoryToxin Ranges, for more information.Table 2: Test Category B Characteristics and CriteriaTest Category B: Basic Biochar Toxin Reporting - Required for All FeedstocksRequirementEarthworm AvoidanceTestGermination InhibitionAssayPolycyclic AromaticHydrocarbons (PAH)Range of MaximumAllowed ThresholdsPass/FailPass/Fail6 – 20 mg /kg TMTest MethodISO 17512-1:2008 methodology and OECDmethodology (1984a) as described by Van Zwietenet al. (2010), see Appendix 3OECD methodology (1984b) 3 test species, asdescribed by Van Zwieten et al. (2010), seeAppendix 3Method following US Environmental ProtectionAgency (1996)Furan 0.5 ng/kg I-TEQDioxin 0.5 ng/kg I-TEQUS Environmental Protection Agency (2007)21221 The following jurisdictions were used to construct the range of values: Australia, Canada, EU, UK, USA.These entities were chosen as standards because they all have a long history of regulations addressingthese toxins in soils and other substrates.International Biochar Initiative – Guidelines for Specifications of Biochars for Use in Soils 14