Total Delta-9 THC Is a Computed Value. Here Is the Arithmetic.

Total delta-9 THC is the single most frequently misread figure in Texas hemp compliance, and the reason is structural: it is not a number a laboratory reads off an instrument. It is a number derived from two others.

The arithmetic

total delta-9 THC = delta-9 THC + (0.877 x THCA)

The coefficient reflects the mass lost when THCA decarboxylates into delta-9 THC. THCA is not itself delta-9 THC, but under heat it converts, and the rule accounts for that conversion rather than ignoring it.

The practical consequence is direct: a delta-9 figure that looks comfortable in isolation can sit next to a THCA value that changes the result materially. Reading only the delta-9 line is not a conservative shortcut. It is a different measurement.

Three values are required, not one

Under §300.301(d)(12), a certificate of analysis must report three separate results:

1. delta-9 THC
2. total delta-9 THC
3. total THC per container

A certificate missing any one of the three is non-passing on that field.

Source: 25 TAC §300.301(d), adopted rules filed with the Secretary of State March 2, 2026 (TRD-202601066). In effect March 31, 2026.

The underivable case

Where a laboratory reports delta-9 without reporting THCA, the total delta-9 THC value is not merely absent from the page — it is underivable from the document in front of you. No amount of careful reading recovers it, because the input required to compute it was never reported.

This is worth recognising as a distinct failure mode. It is not a certificate with a gap you can fill by inspection. It is a certificate that cannot answer a required question.

The threshold itself

The adopted rules bind total delta-9 THC at "0.3% or less", inclusive, with a measurement-of-uncertainty allowance applied to the range. The threshold provisions sit at 25 TAC §300.301(a)(4) and (b)(4), and §300.302(b)(1) and (c)(3).

Two precise points follow.

First, the threshold binds total delta-9 THC specifically — one of three distinct tested measures. It is not a general THC limit and it is not the same as total THC per container.

Second, the field-set rule at §300.301(d) and the threshold provisions are separate records. Section 300.301(d) is the certificate-of-analysis field set and carries no threshold of its own. An earlier and fairly widespread reading bound the two together. That binding was wrong, and it produces confident conclusions that the text does not support.

What is open

The threshold text is verified against the adopted rules and the Texas Register adoption notice.

The enforcement posture attaching to that threshold is a separate question, and it remains under review. This page asserts it in neither direction, and any source that states it confidently is going beyond what the record currently supports.

That distinction is not academic. Effective and enforced are different questions with different answers, and collapsing them is how an operator ends up confidently wrong about their exposure.

What this means in practice

The defensible operator position has three parts:

• Get all three THC values onto the certificate. Treat a missing THCA as a certificate defect, not a rounding issue.
• Compute total delta-9 THC correctly rather than substituting the delta-9 line.
• Treat the enforcement question as open rather than settled, and do not build a decision on an assumption in either direction.

The free HempDash COA check reflects this directly: where it encounters this rule, it returns NEEDS_REVIEW rather than a pass or a failure, because a pass would assert something the record does not establish.