Which Preparation Moved Your September Escalator?

Water treating compounds priced at 251.072 in August. In September they priced at 251.072, to the third decimal.

Automotive chemicals moved 0.22%. Evaporated salt has no September print at all.

And the industry index those three lines sit under, NAICS 325998, rose 3.15% in one month to an all-time high. That is the seventh-largest of 495 monthly moves in a series that starts in June 1985.

"If three of the four published lines didn't move, what did?"

One line did all of it. BLS labels it "all other chemical preparations, including essential oils, matches, and gelatin," and it rose 5.33% in September. Largest one-month increase in the whole series, ahead of June 2022's +5.28% and ahead of every January reset in forty-one years. Four of the five basic-chemical indexes that feed those preparations fell in the same month, petrochemicals hardest at -4.98% (chart below).

The Line Was Asleep Until It Wasn't

For the twelve months July 2025 through June 2026, that preparations index held a band of 279.728 to 281.817. A spread of 0.75% across a year.

Then July printed 275.545, August 277.862, and September 292.660.

Here's the number that should get your attention: in August this line was running 1.02% below a year earlier. In September it is 4.22% above.

The one month is larger than the entire twelve-month change.

Roll it up and the same thing happens one level higher. The 3259 group, which also carries printing ink (+0.01%), explosives (+0.14%), custom compounding (+0.39%) and photographic chemicals (+1.40%), rose 1.71% to its own series high.

Chemical manufacturing as a whole fell 0.20% in September.