Letter to the editor regarding a cigar smoke and cigar tobacco TSNA study of market cigars. Cigar vocabulary and testing are complex and evolving as highlighted by this letter and the authors' response also attached. https://doi.org/10.1021/acs.chemrestox.2c00082

1. Comments on “Tobacco-Specific Nitrosamines in the Tobacco and
Mainstream Smoke of Commercial Little Cigars”
Cite This: https://doi.org/10.1021/acs.chemrestox.2c00082 Read Online
ACCESS Metrics & More Article Recommendations
To the Editor:
We have read the article entitled “Tobacco-Specific Nitros-
amines in the Tobacco and Mainstream Smoke of Commercial
Little Cigars” by Edwards, S., Hassink M., Taylor, K., Watson,
C., Kuklenyik, P., Kimbrell, B., Wang, L., Chen, P., and Valentín-
Blasini, L. published in Chemical Research in Toxicology 2021, 34
(4) 1034−1045. While we are pleased to see an extensive study
that increases the understanding of cigar smoke science, a
discipline in further development, we wish to note some
concerns with the publication.
First, we understand that the study was meant to make a
comparison between “little cigars” and conventional cigarettes.
It should be noted, however, that the cigar brands used in the
study do not fall into the defined tax category of “little cigars”. In
fact, for tax purposes, these products are “large cigars”.1,2
In
general terms, these products are more accurately described as
large-filtered cigars (“LFC”). Further, it should be noted that
some of the cigar products tested in the study fall outside even
the general parameters for LFC and certainly for “little cigars”.
For example, Panter and Café Crème cigars in the study are
characterized as small cigarillos. These products are, therefore,
out of the described scope of the study.
More importantly, the study utilized only cigarette smoking
regimes for all products and cigarette reference products, never
acknowledging that there are established cigar smoking regimes
for these cigar products and established cigar reference products.
The design attributes of the LFC are markedly different than
those of cigarettes. They use different tobaccos, have different
draw characteristics, and are wrapped in tobacco rather than
paper. Strikingly, the cigars tested in the study were nearly
double in median tobacco weight, at 1089 mg, compared to the
cigarettes tested, at 661 mg. The median filter ventilation was
0.9% for the cigars compared to 26% for the study cigarettes.
Cigar reference products include 1C2, an LFC, designed for use
in smoking studies, available since 2019, and RT6 and RT8 cigar
tobacco reference products, available since 2017 and 2018,
respectively. These products are from the same supplier from
which the study authors obtained the cigarette reference
products.3
FDA-CTP has sponsored a project to develop
certified reference products for cigar testing including a design
akin to the 1C2.4
Had the authors utilized these cigar regimes
and reference products, valuable information would have been
provided and a link established between previously published
data and future studies for cigars. At a minimum, the authors had
an obligation to discuss the existing cigar reference products and
smoking regimes for the reader’s edification and understanding
of the basis for their exclusion, and to discuss any necessary
modifications to the cigarette regime to avoid particulate
breakthrough during smoking.
As the authors acknowledge, cigar tobacco is grown and
sourced differently than cigarette tobacco. Table S-4 in the
publication also provides a sound presentation of the very
significant physical parameter differences between LFC and
cigarettes. These tobaccos and their physical differences are also
relevant to significant differences in smoke chemistry. Each of
these factors makes the cigarette and smokeless tobacco
products tested inadequate for use as the reference products
in a cigar study, especially given that matched-design reference
products exist.
Regarding smoking, while the LFC size allows for smoking
under cigarette regimes, these regimes are not generally
considered appropriate for cigar smoking. Products categorized
as cigars for regulatory and analytical purposes span a very wide
range of design features, with diameters ranging from
approximately 6 mm to over 25 mm and weights from 1 g to
more than 15 g. Smoking regimes for the category must account
for this wide field of design. Additionally, a critical concern for
cigar smoking is self-extinguishment during machine-smoking.
Researchers with expertise in cigar smoking, working collabo-
ratively across international and competitive boundaries,
developed and implemented a machine-smoking regime and
associated procedures addressing the unique challenges and
characteristics of cigars. A key difference for cigar smoking is that
the regime has been designed to maintain constant puff velocity
(by varying puff volume based on diameter) to allow
comparisons between products and to minimize self-extinguish-
ment. Also, larger traps and fewer cigars/trap are used to avoid
particulate breakthrough. These methodologies, in use since
2005, are updated routinely through cross-industry controlled
collaborative studies, of which there are some 15 independent
studies to date.5
In conclusion, while we agree that more research to
understand cigar HPHC content and yields is needed, this
study would be more valuable with discussion and use of well-
established cigar-specific smoking regimes and reference
Letters to the Editor
pubs.acs.org/crt
Published XXXX by American Chemical
Society
A
https://doi.org/10.1021/acs.chemrestox.2c00082
Chem. Res. Toxicol. XXXX, XXX, XXX−XXX
Downloaded
via
71.69.225.124
on
June
25,
2022
at
01:15:05
(UTC).
See
https://pubs.acs.org/sharingguidelines
for
options
on
how
to
legitimately
share
published
articles.

2. products acknowledging different methodological requirements
for comparability of results and significance of conclusions.
Inclusion of LFC, cigarillos, or small cigarillos in a “little cigar”
study may furthermore lead to false interpretations of the results
and be misleading to the reader.
Rana Tayyarah
■ AUTHOR INFORMATION
Complete contact information is available at:
https://pubs.acs.org/10.1021/acs.chemrestox.2c00082
■ REFERENCES
(1) 15 U.S. Code § 1332; U.S. Government.
(2) 27 U.S.C. § 40.11; U.S. Government.
(3) CTRP Products. Reference Cigarettes; University of Kentucky
College of Agriculture, Food and Environment, 2021. https://ctrp.uky.
edu/products/gallery/Cigars (accessed 07-21-2021).
(4) Cigar Reference Products Program Project Number
5UC2FD006890−02. RePORT; NIH, 2021. https://reporter.nih.
gov/search/La7AngoXP0mgQQY4X39rWA/project-details/
10063874 (accessed 07-21-2021).
(5) CSM-Cigar Smoking Methods - 2006; Cooperation Centre for
Scientific Research Relative to Tobacco, 2021. https://www.coresta.
org/groups/cigar-smoking-methods (accessed 07-21-2021).
Chemical Research in Toxicology pubs.acs.org/crt Letters to the Editor
https://doi.org/10.1021/acs.chemrestox.2c00082
Chem. Res. Toxicol. XXXX, XXX, XXX−XXX
B