# Total THC vs Delta 9 Total THC vs Delta-9

Understanding THC Potency Reporting
THCa is the inactive form of the THC molecule that plants naturally produce.
The plant produces only a fraction of active delta-9 THC (delta-9-THC) form.
The conversion of inactive THCa to active delta-9-THC occurs when it is heated.
Only 87.7% can be converted into active delta 9-THC.

THCa and Delta 9-THC Reporting Labs now have to report THCa values and calculate delta 9-THC from THCa

Example of Reporting and Total HHC CalculationThe data shown (top right) indicated a THCa content of 24. 34% with a 9-THC content 0. 74% is the sample.
To calculate the maximum 9THC from THCa, multiply the THCa value by 0 .887.
24. 34% (THCa), x 0. 877=21. 34% Maximum THC from THCs
To calculate the final “Total Hc” value, add the maximum THC content from THCs to the amount of THCs that was in the sample.
21. 34% (from THCa calculation + 0. 74% ^9-THC (from the plant)=22. 08% “Total THC”.

Delta-9 THC Testing for Hemp under CT Public Act 19-3 August 27, 2019
The lab might dry the sample before extracting THCA or delta-9 THC. This is to provide a dry weight basis and convert THCA into delta-9 THC. The following methods must be used for analysis:
a. Gas chromatography using flame ionization detection (GC–FID) which converts THCA into THC during analysis. The test result of our analysis will be total delta-9 HHC.
b. Use the formula below to calculate delta-9 THC from THCA by high performance liquid chromatography (HPLC).

Labs Processing Wet Samples
Laboratory personnel who process wet samples must calculate a dry mass separately, and then apply this measurement to the test results to convert to dry-weight basis.
Wet sample processing labs must use a method that can measure both THCA AND delta-9 THC. The formula on the next slide will convert THCA into delta-9 THC.
Other metabolites of THC may exist, but only THCA is included in calculations.
Delta-8 THC, not delta-9 THC, is not included in the calculation.

Formula to Use:
The total theoretical tetrahydrocannabinol (or THC) content in hemp is the maximum possible amount of delta-9 tetrahydrocannabinol within a crop. It would be calculated using the following calculation:
the sum of the concentration of delta-9 tetrahydrocannabinol and its precursor, tetrahydrocannabinol-A, multiplied by 0. 8777 based on dry weight and reporting to two significant figures.

Method of Testing
The Certificate of Analysis (COA) must be signed by the lab indicating the method of testing. A COA must include a statement indicating whether the sample contains delta-9 THC levels greater than 0.3% on dry weight.
The reporting limit is 0.3% delta-9THC. This includes any measurement uncertainty that is determined by the laboratory. As an example, if the measurement uncertainty is 30%, the reporting limit will be 0. 39% THC, and all samples lower than 0. and all samples below 0.5% THC will be reported as .a. Results below the reporting limit will be reported as less than 0.3% and given a result status “pass “
“.b. b.