When Froomes sample was adjusted for dehydration it came down to 1200 apparently.
From Cycling News:
Froome's uncorrected salbutamol level was 2000ng/mL, as reported last year in the original story published by The Guardian and Le Monde on December 13. That value is double WADA's limit of 1000ng/mL (eg., the maximum concentration that it considers as evidence that an athlete used the permitted therapeutic dose).
However, WADA's technical documents, which date back to at least 2014, allow for uncertainty in lab measurements of 10 percent. When deciding whether or not a reading warrants further investigation as an Adverse Analytical Finding (AAF), they use a 'decision limit' (DL) of 1200ng/mL. Froome's sample was 66.7 per cent over that limit.
WADA's newest rules allow for even further adjustment of the limit.
There has also been an allowance for urine samples that are highly concentrated because of dehydration, but a correction for this was only applied to 'endogenous substances' (growth hormone, steroids) before a WADA 2018 technical document was issued on November 15, 2017.
Although TD2018DL did not go into effect until March 1, 2018, by Froome's comments, and The Times' previous report that his corrected salbutamol level was 1429ng/mL, it can be concluded that WADA retroactively applied the correction to his pending case, bringing the decision limit up from 1200ng/mL to 1680ng/mL*.
With an adjustment for dehydration, Froome's stage 18 Vuelta sample was still 19.05 per cent over the decision limit.
"The classic [inaccuracy] from the start was of my result being double the limit when it was less than 20 per cent over with the figure corrected," Froome told The Times.
While Froome was still clearly over the decision limit, 20 per cent over is a bit easier to explain away than 66.7 per cent. While WADA rules allow for riders to undergo a controlled pharmacokinetic study to demonstrate under laboratory conditions that their bodies excrete more salbutamol than normal, the agency acknowledged that given the unique conditions of a Grand Tour – variability in Froome's doping controls over the Vuelta, which he led from stage 3 to the finish, and other factors – it would not be practicable to reproduce this kind of salbutamol excretion result.
The case also led to a rare WADA admission that "in rare cases, athletes may exceed the decision limit concentration without exceeding the maximum inhaled dose".
David Walsh’s column on Sunday will be a fascinating read.