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              WAYNE BAGLEY ET AL. v. ADEL
                 WIGGINS GROUP ET AL.
                      (SC 19835)
        Palmer, Eveleigh, McDonald, Espinosa and Robinson, Js.*

                                  Syllabus

The plaintiff, the executrix of the estate of the decedent, sought to recover
   damages, pursuant to Connecticut’s Product Liability Act (§ 52-572m et
   seq.) for, inter alia, the wrongful death of the decedent under theories
   of negligence and strict liability. The plaintiff alleged that the decedent
   was exposed during his employment with S Co. to an asbestos containing
   product manufactured by the defendant and that exposure contributed
   to his contraction of mesothelioma, a cancer that is caused by the
   inhalation of asbestos fibers. She further alleged that the defendant’s
   actions in selling its product constituted violations of the act in that its
   product was unreasonably dangerous and that the defendant knew or
   should have known that its product was inherently dangerous and yet
   failed to use reasonable care by not testing the product to ascertain its
   danger or removing the product from the marketplace. At trial, one of
   the decedent’s former coworkers testified that the defendant’s product
   was subject to sanding and that the sanding process created visible dust
   to which the decedent would have been exposed. The plaintiff’s expert
   witnesses testified about the history of the asbestos industry, asbestos
   related diseases, and how certain exposure to asbestos can cause meso-
   thelioma. One expert, A, opined that a proximate cause of the decedent’s
   mesothelioma was his exposure to the defendant’s product at S Co.
   After the plaintiff rested her case, the trial court denied the defendant’s
   motion for a directed verdict, concluding that the plaintiff had presented
   sufficient evidence to support her theories of liability. Thereafter, the
   jury returned a verdict for the plaintiff on her negligence and strict
   liability claims, and the trial court denied the defendant’s motion to set
   aside the verdict and for judgment notwithstanding the verdict. From
   the judgment rendered in favor of the plaintiff, the defendant appealed.
   Held that the plaintiff failed to prove through expert testimony that
   respirable asbestos fibers in a quantity sufficient to cause mesothelioma
   were released from the defendant’s product when it was used in the
   manner that it was at S Co. during the decedent’s tenure there and,
   accordingly, she failed to prove her case: the defendant did not concede
   that its product, when sanded, emitted respirable asbestos fibers that
   the decedent could have inhaled, that was not a matter within the
   common knowledge of lay jurors, none of the plaintiff’s witnesses had
   done any testing or examination of the defendant’s product or a similar
   product to establish that such fibers are emitted when such a product
   is sanded, A did not possess any specialized knowledge about how
   adhesive products containing asbestos, such as the defendant’s product,
   behave when they are utilized as the defendant’s product was under
   the conditions at S Co., and, in light of these gaps in the evidentiary
   record, the trial court improperly denied the defendant’s motion for a
   directed verdict and its motion to set aside the verdict and for judgment
   notwithstanding the verdict; moreover, the requirement of an expert
   witness to prove whether the defendant’s product emitted respirable
   asbestos fibers when sanded, subject matter that was technical in nature
   and beyond the field of the ordinary knowledge of a lay juror, was
   required under well established law that existed at the time of trial and
   predated this court’s recent product liability jurisprudence, Bifolck v.
   Philip Morris, Inc. (324 Conn. 402), and Izzarelli v. R.J. Reynolds
   Tobacco Co. (321 Conn. 172), and, therefore, the plaintiff was not entitled
   to a new trial.
           Argued April 5—officially released November 7, 2017

                             Procedural History

   Action to recover damages for personal injuries sus-
tained as a result of an allegedly defective product
designed, manufactured or sold by the defendants, and
for other relief, brought to the Superior Court in the
judicial district of Fairfield, where the action was with-
drawn as to the named defendant et al.; thereafter,
the court, Bellis, J., granted the motion for summary
judgment filed by Raytheon Company et al.; subse-
quently, Marianne Bagley, executrix of the estate of
Wayne Bagley, was substituted as the named plaintiff;
thereafter, the case was tried to the jury before Rad-
cliffe, J.; subsequently, the court, Radcliffe, J., denied
the motion of the defendant Wyeth Holdings Corpora-
tion for a directed verdict; verdict for the plaintiffs;
thereafter, the court, Radcliffe, J., denied the motion
of the defendant Wyeth Holdings Corporation to set
aside the verdict and for judgment notwithstanding the
verdict, and rendered judgment in accordance with the
verdict, from which the defendant Wyeth Holdings Cor-
poration appealed. Reversed; judgment directed.
  Katharine S. Perry, with whom were James A. Hall
and, on the brief, Mark O. Denehy and Michael T.
McCormack, for the appellant (defendant Wyeth Hold-
ings Corporation).
  Kenneth J. Bartschi, with whom were Robert M.
Shields, Jr., and, on the brief, Christopher Meisenko-
then, for the appellee (plaintiffs).
                         Opinion

   PALMER, J. The issue presented by this appeal is
whether, in an action brought pursuant to Connecticut’s
Product Liability Act (act), General Statutes § 52-572m
et seq., under strict liability and negligence theories,
expert testimony was necessary to prove that a defec-
tive, asbestos containing product caused a worker who
came in contact with that product to contract a fatal
lung disease. The defendant1 Wyeth Holdings Corpora-
tion appeals2 from the judgment of the trial court ren-
dered following a jury verdict in favor of the plaintiff
Marianne Bagley.3 The jury awarded the plaintiff dam-
ages for the wrongful death of her husband, Wayne
Bagley (decedent), and for loss of consortium after
concluding that the decedent’s death was caused by
the defendant’s negligence and by its sale of an unrea-
sonably dangerous product to the decedent’s former
employer, Sikorsky Aircraft Corporation (Sikorsky).4
The defendant claims that the trial court improperly
denied its motion for a directed verdict and its motion
to set aside the verdict and for judgment notwithstand-
ing the verdict because the plaintiff failed to prove both
that the product at issue was unreasonably dangerous
and that it was a legal cause of the decedent’s fatal
lung disease. We agree and, accordingly, reverse the
judgment of the trial court.
   The following facts, which the jury reasonably could
have found, and procedural history are relevant to our
disposition of this appeal. The decedent was employed
at Sikorsky from 1979 until shortly before his death in
2012. For approximately ten months in 1979 and 1980,
he worked as a manufacturing engineer in the compos-
ite blade manufacturing and development department
(blade shop), where various helicopter blades were
manufactured. The decedent’s office was located on a
mezzanine overlooking the area where the blade pro-
duction took place. According to a coworker, however,
the decedent often entered the production areas to
assist in resolving the various issues that arose during
the manufacturing process.
   During the time that the decedent worked in the blade
shop, the defendant manufactured and sold to Sikorsky
an adhesive product known as FM-37.5 FM-37 was used
in the blade shop to bind together interior components
of helicopter blades. It was made of modified epoxy
material, supplied in sheet form with strippable release
paper, and contained 8.6 percent asbestos. In regular
usage, FM-37, after application, was heated until it
foamed and expanded. When it expanded onto areas
of the blades where it was not supposed to be, it was
removed with chisels or by sanding. Product informa-
tion sheets that the defendant supplied for FM-37 did
not indicate that it contained asbestos and further
stated that the product could be sanded after curing.
  The decedent was diagnosed with mesothelioma on
or about August 10, 2011. Mesothelioma is a cancer
occurring in the outer cells of the pleura, a membrane
surrounding the lung. It is a ‘‘signature’’ or ‘‘sentinel’’
disease for asbestos exposure, meaning that such expo-
sure is the only known cause. Mesothelioma is caused
by the inhalation of asbestos fibers and typically takes
decades to develop. There is a dose-response relation-
ship between asbestos exposure and mesothelioma; in
other words, the more exposure a person has, the
greater is the likelihood that he or she will contract
the disease.
   In the course of the litigation of this case, the dece-
dent acknowledged that he had been exposed to asbes-
tos secondarily due to his father’s employment at a
shipyard from 1958 through 1961, and directly during
three separate home renovation projects in the 1960s
and 1970s. Additionally, a workers’ compensation bene-
fits application entered into evidence reveals that the
decedent filed a claim for benefits indicating that he
had been exposed to asbestos during his employment
with the Torrington Company, prior to his employment
at Sikorsky.
   In the operative complaint, the plaintiff alleged that
the decedent was exposed to asbestos containing prod-
ucts while working at Sikorsky and that the exposure
had contributed to his contraction of mesothelioma.
She alleged further that the defendant’s actions in sell-
ing such asbestos containing products constituted viola-
tions of the act in that (1) the products were
unreasonably dangerous, that is, dangerous to an extent
beyond that which the ordinary worker in the position
of the decedent would have contemplated (strict liabil-
ity claim),6 and (2) the defendant knew or should have
known that the products were inherently dangerous, yet
failed to use reasonable care by, inter alia, not testing
or conducting research on the products to ascertain
their dangers, or removing the products from the mar-
ketplace (negligence claim).7
   The plaintiff presented the testimony of several wit-
nesses at trial. Barry Castleman testified as an expert
in public health and the history of the asbestos industry
and asbestos related disease. Castleman explained that
the dangers of asbestos to industrial workers began to
be known as early as the late nineteenth century and
that companies, including the defendant, were cogni-
zant of the dangers of inhaling asbestos dust as early
as the 1940s. In response to a hypothetical posed by the
plaintiff’s counsel, Castleman opined that a company
producing an adhesive product at approximately the
time that the defendant produced FM-37 would have
been aware that relatively low exposures to asbestos,
which might occur from sanding, could cause mesothe-
lioma, and that the company, having that knowledge,
could have done air sampling under foreseeable condi-
tions of use to determine what level of exposure would
be created. On cross-examination, Castleman acknowl-
edged that he did not examine FM-37 and did not know
what percentage of it was asbestos, what its other ingre-
dients were or whether it contained any bonding agent.
Castleman further acknowledged that he was unaware
of any other case in which someone had developed
mesothelioma as a result of exposure to a similar
product.
  Carl Ulsamer, a senior materials engineer at Sikorsky,
testified as to the asbestos containing materials that
were used in the blade shop at Sikorsky in 1979 and
1980. He identified FM-37, as well as two other adhesive
products manufactured by another company. On cross-
examination, Ulsamer named several other asbestos
containing products that had been in use elsewhere at
Sikorsky and agreed that, over the years, the company
had used many asbestos containing components in man-
ufacturing its helicopters.
   Michael Petrucci, a coworker of the decedent who
held a similar position in the blade shop in 1979 and
1980, testified that the two had adjacent desks in a
mezzanine area overlooking the shop but would spend
some of their time on the shop floor troubleshooting
problems. Petrucci described the layout of the blade
shop, which had various rooms, including one where
various blades were cured and sanded during produc-
tion. According to Petrucci, he and the decedent would
have worked all over the blade shop on a daily basis,
including in the sanding room, and workers in the sand-
ing room also would move about the shop. Petrucci
recalled the asbestos containing adhesives that Ulsamer
had identified, and he confirmed that both FM-37 and
an asbestos containing adhesive supplied by another
manufacturer were subject to sanding. He testified that
the sanding process created visible dust to which he
and the decedent would have been exposed. The sand-
ing room was equipped with a ventilation system that
collected some of the dust. During Petrucci’s time at
Sikorsky, no one informed him that there was asbestos
in the dust from FM-37.
   Arnold Brody, a pathologist, testified in detail as to
the process by which asbestos causes mesothelioma.
Brody’s presentation, however, was premised on the
assumption that a person has been exposed to respira-
ble asbestos fibers; he did not review any materials
specific to the decedent’s case. In short, he explained
that mesothelioma can result when a person inhales
tiny asbestos fibers that then make their way past the
various defense mechanisms of the body and lodge
deeply in the lungs. Brody spoke of animal experiments
that he had conducted using dust from raw asbestos
but confirmed, on cross-examination, that he had not
experimented with asbestos containing products.
  Finally, Jerrold L. Abraham, a pathologist and expert
in pulmonary pathology, occupational and environmen-
tal medicine, and asbestos related disease, reviewed
the decedent’s medical records, a pathology slide and
other evidence in the case.8 He opined that the decedent
had mesothelioma and that a proximate cause of that
disease, among others, was the decedent’s exposure to
asbestos from FM-37 in the blade shop. Prior to render-
ing his opinion, Abraham explained to the jury the dose-
response relationship between asbestos and mesotheli-
oma, and how low levels of exposure to asbestos, above
the ambient levels that may exist in the general environ-
ment, can contribute to causing that disease. He further
explained the concept of fugitive exposure, whereby
individuals may be exposed to asbestos when they are
not working directly with an asbestos source but,
rather, are in its general vicinity or have contact with
other people who work with it, and how even such
indirect exposure could cause mesothelioma.
   In rendering his opinion on causation, Abraham
responded to a hypothetical question from the plaintiff’s
counsel that presumed that the decedent had worked
in the Sikorsky blade shop for ten months, was in and
out of the sanding room periodically and was exposed
to visible dust from the sanding of FM-37 both in that
room and from contact with workers who sanded
blades and then moved about the shop. The hypotheti-
cal further directed Abraham to assume that FM-37
contained 8.6 percent asbestos. Abraham responded
that what counsel had articulated was ‘‘a very clear
description of an exposure to asbestos being released
from working with an asbestos containing material’’ and
that the presence of dust indicated inadequate control.
Abraham confirmed that counsel’s hypothetical paral-
leled the facts of the case as they had been described
by Petrucci, the testimony of whom Abraham had
reviewed. He later opined that a product that was only
8.6 percent asbestos still would contain a large number
of asbestos fibers. On cross-examination, however,
Abraham agreed that, in preparing his opinion, he did
not inspect FM-37 or speak with anyone at Sikorsky
about the ventilation in the sanding room in 1979 and
1980.
  After the plaintiff rested her case, the defendant
moved for a directed verdict, arguing that the plaintiff
had failed to establish a prima facie case for liability
under the act. Specifically, the defendant argued that
the plaintiff had failed to present any evidence of either
a design defect in FM-37 or that asbestos dust from
FM-37 had caused the decedent’s injuries and death.
According to the defendant, expert testimony was nec-
essary to prove the dangerousness of FM-37 because it
was a complex product for which an ordinary consumer
could not form a safety expectation. As to causation,
the defendant argued that there was insufficient evi-
dence that the decedent had been exposed to dust in
the sanding room, and, further, there was no expert
evidence that the dust contained asbestos fibers that
were released from FM-37 at a level sufficient to cause
mesothelioma. The trial court denied the defendant’s
motion for a directed verdict, reasoning that the plaintiff
had presented sufficient evidence from which the jury
could conclude that FM-37 was unreasonably danger-
ous and that the defendant had been negligent in failing
to test it or in selling it, and that defect and negligence
had proximately caused the decedent to contract meso-
thelioma.
   Following the court’s denial of its motion, the defen-
dant rested its case without presenting any witnesses.9
The trial court charged the jury, instructing it as to
general negligence principles and, in regard to the strict
liability claim, as to the ordinary consumer expectation
test. While the jury was deliberating, it sent a note to
the court asking whether the dust or powder from FM-
37 had ever been tested. The court responded that there
was no evidence one way or the other on that topic.
Thereafter, the jury returned a verdict in the plaintiff’s
favor on both her negligence and strict liability claims,
as well as on her loss of consortium claim. It awarded
total damages of $804,777.
   Subsequently, the defendant filed a motion to set
aside the verdict and for judgment notwithstanding the
verdict. As to the jury’s finding of negligence, the defen-
dant argued that there was no evidence that it was
negligent in selling or in failing to test or conduct
research on FM-37, which contained 8.6 percent asbes-
tos encapsulated in resin and was not shown to be
dangerous, or that its negligence had caused the dece-
dent’s illness and subsequent death. As to the jury’s
strict liability finding, the defendant contended that
there was insufficient evidence that FM-37 was unrea-
sonably dangerous and that a defect in that product
had caused the decedent’s illness and subsequent death.
Regarding causation, the defendant argued that there
was insufficient evidence that the decedent was in the
sanding room or otherwise in the vicinity of FM-37 or
its dust, and also no evidence that sanding FM-37 caused
respirable asbestos fibers to be released from that prod-
uct. The defendant contended that expert testimony
was necessary for the plaintiff to prove both dangerous-
ness and causation so as to prevail on either legal the-
ory. The court denied the defendant’s motion to set
aside the verdict and for judgment notwithstanding the
verdict, again concluding that the evidence presented
was sufficient to support both theories of recovery.
This appeal followed.
  The defendant claims on appeal that the trial court
improperly denied its motions for a directed verdict
and to set aside the verdict and for judgment notwith-
standing the verdict because the plaintiff failed to pro-
duce expert testimony establishing that FM-37 was a
defective product. The defendant argues that such testi-
mony was necessary due to the specialized and techni-
cal nature of the product at issue and to prove, among
other things, the product’s dangerousness and the risks
inherent in its use. In the defendant’s view, the plaintiff’s
failure to produce expert testimony pertaining to FM-
37 was fatal to both her strict liability claim and her
negligence claim10 because each type of claim necessar-
ily requires proof of an unreasonably dangerous prod-
uct. The defendant claims additionally that the plaintiff
failed to prove that asbestos released from FM-37 was
the proximate cause of the decedent’s mesothelioma
because there was no direct evidence that he worked
in the vicinity of FM-37 or any evidence that he was
exposed to any asbestos released from that product.11
   The plaintiff, in response, maintains that expert testi-
mony was unnecessary to prove the existence of a
defective product, under either a strict liability theory
or a negligence theory. As to strict liability, the plaintiff
contends that FM-37 is not a complex product, and,
therefore, the ordinary consumer expectation test,
which does not require expert testimony and on which
the jury was instructed, applies. Specifically, she claims,
it is within the ken of ordinary jurors to understand
that sanding a product creates dust, and, in the present
case, the product at issue contained asbestos that, as the
evidence introduced at trial established, is dangerous
to inhale. In the plaintiff’s view, ‘‘it is easy to see that
sanding a product containing asbestos would create
dust containing asbestos.’’ In regard to negligence, the
plaintiff claims that that cause of action may be proven
by applying ordinary negligence principles and without
a showing that a defendant’s product is unreasonably
dangerous as contemplated by the strict liability stan-
dard. Regarding causation, the plaintiff contends that
there was ample circumstantial evidence that the dece-
dent was exposed to dust from the sanding of FM-37
either directly or when it drifted throughout the blade
shop, and, further, the expert testimony she introduced
established that, when it comes to mesothelioma, there
is no safe level of exposure to asbestos. In the plaintiff’s
view, because there is no safe level of exposure, the
jury reasonably could infer that FM-37’s 8.6 percent
asbestos was a significant amount and, moreover, that
dangerous levels of asbestos were present in the dust.
   In its reply brief, the defendant contends that, regard-
less of what theory of liability is employed, the plaintiff
failed to prove, as required by the act, that FM-37 was
defective and that the defect caused the decedent to
contract mesothelioma. Specifically, there was no evi-
dence showing that respirable asbestos fibers could
have been released from FM-37, given that there was
no witness, lay or expert, who performed any testing,
examination or analysis of that product. The defendant
further maintains that, under either a strict liability or
negligence theory, the plaintiff was required to show
that FM-37 was unreasonably dangerous, and the plain-
tiff failed to do so.
   We agree with the defendant that the plaintiff failed
to prove that respirable asbestos fibers were released
from FM-37 during sanding in the blade shop. Without
such proof, there was insufficient evidence to show
either that FM-37 was dangerous or that it was a legal
cause of the decedent’s mesothelioma. Because lack of
proof on these matters was fatal both to the plaintiff’s
strict liability claim and to her negligence claim, the
trial court improperly denied the defendant’s motion
for a directed verdict and its motion to set aside the
verdict and for judgment notwithstanding the verdict.
   We begin with the applicable standard of review and
general governing principles. ‘‘The standards for appel-
late review of a directed verdict are well settled.
Directed verdicts are not favored. . . . A trial court
should direct a verdict only when a jury could not rea-
sonably and legally have reached any other conclusion.
. . . In reviewing the trial court’s decision [to deny
the defendant’s motion for a directed verdict] we must
consider the evidence in the light most favorable to the
plaintiff. . . . Although it is the jury’s right to draw
logical deductions and make reasonable inferences
from the facts proven . . . it may not resort to mere
conjecture and speculation. . . . A directed verdict is
justified if . . . the evidence is so weak that it would
be proper for the court to set aside a verdict rendered
for the other party.’’ (Internal quotation marks omitted.)
Metropolitan Property & Casualty Ins. Co. v. Deere &
Co., 302 Conn. 123, 150, 25 A.3d 571 (2011). The forego-
ing standard of review also governs the trial court’s
denial of the defendant’s motion for judgment notwith-
standing the verdict because that motion ‘‘is not a new
motion, but [is] the renewal of [the previous] motion for
a directed verdict.’’ (Internal quotation marks omitted.)
Haynes v. Middletown, 314 Conn. 303, 312, 101 A.3d
249 (2014). A directed verdict properly is rendered when
expert testimony is necessary to prove a plaintiff’s claim
and the plaintiff has failed to produce such expert testi-
mony. See, e.g., Grody v. Tulin, 170 Conn. 443, 451, 365
A.2d 1076 (1976); Young v. Rutkin, 79 Conn. App. 355,
363–64, 830 A.2d 340, cert. denied, 266 Conn. 920, 835
A.2d 60 (2003); Vona v. Lerner, 72 Conn. App. 179,
190–92, 804 A.2d 1018 (2002), cert. denied, 262 Conn.
938, 815 A.2d 138 (2003).
   ‘‘Expert opinions concerning scientific, technical or
other specialized knowledge may be necessary to assist
the trier of fact in understanding the evidence or in
determining a fact in issue. Conn. Code Evid. § 7-2.’’
(Internal quotation marks omitted.) State v. Buhl, 321
Conn. 688, 700, 138 A.3d 868 (2016). Such testimony is
required ‘‘when the question involved goes beyond the
field of ordinary knowledge and experience of the trier
of fact. . . . [Conversely] [t]he trier of fact need not
close its eyes to matters of common knowledge solely
because the evidence includes no expert testimony on
those matters.12 . . . Whether expert testimony is
required in a particular case is determined on a case-
by-case basis and its necessity is dependent on whether
the issues are of sufficient complexity to warrant the
use of the testimony as assistance to the . . . [trier
of fact].’’ (Citation omitted; footnote added; internal
quotation marks omitted.) Id. The trial court’s determi-
nation as to whether expert testimony was necessary
is a legal one subject to plenary review. See, e.g., Doe
v. Hartford Roman Catholic Diocesan Corp., 317 Conn.
357, 373, 119 A.3d 462 (2015).
    After our careful review of the record, we conclude
that the plaintiff’s case lacked essential expert testi-
mony to prove a vital fact in support of her negligence
and strict liability claims, namely, that respirable asbes-
tos fibers in a quantity sufficient to cause mesothelioma
were released from FM-37 when it was used in the
manner that it was in the Sikorsky blade shop during
the decedent’s tenure there. Proof of this fact was nec-
essary to prove both that (1) FM-37 was dangerous, and
(2) FM-37’s dangerous condition caused the decedent
to develop mesothelioma. Although the plaintiff proved
that breathing respirable asbestos fibers above ambient
levels can cause mesothelioma, that FM-37 contained
8.6 percent asbestos and was sanded, producing dust,
and that the decedent was exposed to that dust, both
directly and secondarily, she nevertheless failed to
establish that the dust from the FM-37 necessarily con-
tained respirable asbestos fibers. Moreover, the ques-
tion of whether respirable asbestos fibers are released
by sanding a modified epoxy adhesive product with 8.6
percent asbestos, after it has been heated and cured, is
a technical one whose answer is not within the common
knowledge of lay jurors. Accordingly, competent expert
testimony was necessary to assist them in answering
it. Because the plaintiff did not present such testimony,
the trial court should have granted the defendant’s
motion for a directed verdict or its motion to set aside
the verdict and for judgment notwithstanding the
verdict.
   This case is akin to In re R.O.C., 131 S.W.3d 129, 131
(Tex. App. 2004), a product liability action in which
the Court of Appeals of Texas upheld a trial court’s
summary judgment in favor of the defendant manufac-
turers of asbestos containing paints and other coating
substances. The plaintiffs, who had contracted asbesto-
sis, claimed that respirable asbestos was released when
the products were sprayed or when they were sanded
or ground off of the surfaces to which they had been
applied. Id. The plaintiffs testified that, when they
worked with the products, there was grinding and
scraping occurring all of the time, and that those activi-
ties produced a thick dust. Id., 137. Because the plain-
tiffs failed to produce expert testimony that spraying,
sanding or grinding the products at issue produced the
release of asbestos fibers that could cause asbestosis,
however, the court concluded that they had failed to
prove an exposure to asbestos that could have caused
their injuries. Id., 136–37. In short, in the absence of
expert testimony, proof that there was dust did not
equate to proof that the dust contained respirable asbes-
tos fibers.
   Similarly, in DiSantis v. Abex Corp., Docket No. 87-
0515, 1989 WL 150548, *1 (E.D. Pa. December 8, 1989),
aff’d, 908 F.2d 961, 962 (3d Cir. 1990), a product liability
action, the United States District Court for the Eastern
District of Pennsylvania rendered summary judgment
in favor of defendant suppliers of asbestos containing
electrical equipment used in subway cars, because there
was no evidence to support the plaintiff’s claim of injury
due to his occupational exposure to respirable asbestos
fibers. The plaintiff, who had performed service and
maintenance work on the subway cars, testified that
he and others had cleaned the motors of the cars by
blowing them out with an air hose, which caused a
good deal of accumulated dust to float up around them.
Id., *6–7. The court concluded that this was insufficient
to establish asbestos exposure, however, explaining
that the ‘‘[p]laintiff’s testimony establishe[d] that his
job did expose him to a lot of dust. But he has supplied
no testimony which would establish [that] the dust he
came in contact with contained asbestos.’’ Id., *7; see
also Sterling v. P & H Mining Equipment, Inc., 113 A.3d
1277, 1281–83 (Pa. Super. 2015) (testimony of crane
operator and his coworkers that operator worked in
vicinity of cranes equipped with defendant’s asbestos
containing brakes and wiring and saw dust emanating
from crane’s wheels was insufficient to show that opera-
tor had inhaled dust containing asbestos).13
  In contrast, in cases in which courts have found suffi-
cient evidence of exposure to asbestos fibers causing
an asbestos related disease, there has been, in addition
to testimony that there was visible dust attendant to
the use of a defendant’s product, expert testimony that
the product, when used under conditions similar to
those presented by the case, emitted respirable asbes-
tos fibers. For example, in John Crane, Inc. v. Puller,
169 Md. App. 1, 17–19, 899 A.2d 879, cert. denied, 394
Md. 479, 906 A.2d 943 (2006), the Court of Appeals of
Maryland concluded that there was sufficient evidence
that the defendant’s asbestos containing gaskets and
valve packing were a substantial, contributory factor
in the development of the plaintiff’s mesothelioma. In
addition to the plaintiff’s testimony that he had worked
extensively around those products, which released sub-
stantial dust when used; id., 11–13; and testimony from
an industrial hygienist that a visible dust cloud from an
asbestos product indicates a likely health hazard; id.,
14–15; there was expert testimony from (1) a doctor
of engineering specializing in materials science who
performed testing on asbestos gaskets and valve pack-
ing, along with air sampling, to measure the fiber release
during operations described by the plaintiff, which
revealed that significant amounts of asbestos fibers
were released, and (2) an environmental scientist who
found protruding fibers when examining the gaskets,
demonstrated that fibers would be released if a gasket
was tapped with a screwdriver, cut the gaskets and
observed microscopically that fibers were released and
simulated use of a gasket as the plaintiff described using
it while testing the air, which then contained a large
amount of asbestos fibers. Id., 15–16. The court
described this expert testimony as ‘‘[i]mportant links
in the chain of evidence . . . .’’ Id., 15.
  In Becker v. Baron Bros. Coliseum Auto Parts, Inc.,
138 N.J. 145, 157, 649 A.2d 613 (1994), the plaintiff’s
expert examined brake shoes manufactured by the
defendant with specialized equipment and determined
that they contained respirable asbestos fibers that
potentially were capable of becoming airborne if dis-
turbed. Although the defendant presented testimony to
the contrary, the Supreme Court of New Jersey con-
cluded that the conflicting evidence was sufficient to
create a factual dispute for the jury to resolve whether
dust emitted from the brake shoes could have caused
the plaintiff’s mesothelioma. Id., 158–59; see also In re
Tire Worker Asbestos Litigation, Docket Nos. 88-4540,
88-4704, 88-4706, 88-4850, 88-4852, 88-7749, 1991 WL
195575, *3 and n.5, *5–6 (E.D. Pa. September 25, 1991)
(report of expert in chemistry and environmental mat-
ters concluded that respirable asbestos fibers were
released from defendant’s brake linings during normal
operation and maintenance, which created triable issue
of fact as to whether plaintiffs had inhaled such fibers,
thereby precluding summary judgment for defendant).
   In Estate of Hicks v. Dana Companies, LLC, 984 A.2d
943, 952 (Pa. Super. 2009), appeal denied, 610 Pa. 586,
19 A.3d 1051, 1052 (2011), the Superior Court of Penn-
sylvania, reviewing a decision of the Court of Common
Pleas, concluded that there was sufficient evidence for
a jury to find that the defendant’s asbestos containing
gaskets and rope packing had caused plaintiff’s meso-
thelioma. The plaintiff testified that he had worked with
and near those products throughout his career and that
they had created dust; id., 952–53; and a physician testi-
fied that asbestos fibers were unsafe and caused meso-
thelioma with no known safe threshold. See id., 953–55.
Although the plaintiff did not present expert evidence
that the gaskets and packing emitted respirable asbes-
tos fibers, the defendants’ experts, an industrial hygien-
ist and a chemical engineer, had conceded that the
products emitted some respirable asbestos fibers and
that the defendants had begun to put warning labels
on their products advising users against inhaling their
dust as it could result in serious bodily harm. Id., 956.
  In the present case, the plaintiff adequately estab-
lished, through the testimony of Petrucci, that the dece-
dent had been exposed to dust from the sanding of FM-
37. Furthermore, she presented experts to assist the
jury in understanding that: the inhalation of asbestos
fibers is dangerous, and that this hazard has been
known by manufacturers of industrial products, such
as the defendant, for a very long time; the inhalation
of asbestos fibers is, essentially, the only cause of meso-
thelioma, and the precise disease process is well under-
stood; respirable asbestos fibers, once released into the
air, can drift or be carried on an individual’s clothing
for some distance; and the decedent, who had worked
with or near a number of asbestos containing products,
including FM-37, during his lifetime, had contracted
mesothelioma. An important link in the chain of causa-
tion, however, was missing: the plaintiff failed to prove
that FM-37, when sanded, emitted respirable asbestos
fibers that the decedent could have inhaled. Because
the defendant did not concede this point and it is not
a matter within the common knowledge of lay jurors,
the plaintiff was required to prove it with competent
expert testimony.14
   As we previously noted, Abraham, one of the plain-
tiff’s expert pathologists, in responding to a hypotheti-
cal question from the plaintiff’s counsel concerning
whether dust from sanding FM-37, which contained 8.6
percent asbestos, under the conditions about which
Petrucci had testified, could have caused the decedent’s
mesothelioma, opined that Petrucci clearly had
described an exposure to asbestos released from work-
ing with an asbestos containing material. Abraham’s
opinion, however, was not based on any evidence in
the case. Specifically, none of the experts who testified,
including Abraham, or any other witness, had done any
testing or examination of FM-37 or a similar product
to establish that respirable asbestos fibers are emitted
when the product is sanded.15 Moreover, there is no
indication in the record that Abraham possesses any
specialized knowledge, from his familiarity with pub-
lished studies or research or otherwise, about how mod-
ified epoxy adhesives containing asbestos behave when
they are utilized as they were under the conditions in
Sikorsky’s blade shop.16 Cf., e.g., Caruolo v. John Crane,
Inc., 226 F.3d 46, 52–54 (2d Cir. 2000) (jury, in finding
that asbestos fibers released from defendant’s pipe
packing and gaskets caused worker to contract meso-
thelioma, properly could have relied on testimony of
expert witness that visible dust from products indicated
asbestos exposure, given that witness also testified
about his familiarity with study measuring fiber release
when asbestos containing pipe packing and gaskets are
removed); Vedros v. Northrop Grumman Shipbuilding,
Inc., Docket No. 11-1198, 2015 WL 3916248, *3–4, *6
(E.D. La. June 25, 2015) (court found no reason to
exclude industrial hygienist’s expert testimony regard-
ing fiber release from defendant’s adhesive product
when hygienist, who testified that he had examined
‘‘ ‘tens of thousands’ ’’ of asbestos products throughout
his career, relied on, inter alia, published study by
United States Environmental Protection Agency mea-
suring fiber release from similar product); In re Asbes-
tos Litigation, Docket No. 05C-11-257 (ASB), 2009 WL
1034487, *6 (Del. Super. April 8, 2009) (in opining that
friction brakes released respirable asbestos fibers dur-
ing installation and removal, expert witness properly
relied on research of other expert witnesses, his own
research, agency reports and peer-reviewed scientific
data), aff’d, 981 A.2d 531 (Del. 2009); In re New York
City Asbestos Litigation, 148 App. Div. 3d 233, 238, 48
N.Y.S.3d 365 (2017) (expert testimony that visible dust
contains hazardous levels of asbestos must reference
studies or reports measuring fibers released by prod-
ucts at issue). In light of these gaps in the evidentiary
record, the jury could not have relied on Abraham’s
conclusory testimony to find that the decedent had been
exposed to respirable asbestos fibers from FM-37.
   As a final matter, we must address the question of
whether our holding in this appeal is compelled by the
law as it existed in Connecticut when the case was
tried or, rather, whether it stems from principles newly
articulated in this court’s recent product liability juris-
prudence, namely, our decisions in Bifolck v. Philip
Morris, Inc., 324 Conn. 402, 152 A.3d 1183 (2016), and
Izzarelli v. R.J. Reynolds Tobacco Co., 321 Conn. 172,
136 A.3d 1232 (2016), both of which were decided while
this appeal was pending and, to some degree, concern
the question of when expert testimony is necessary in
a product liability action. The plaintiff contends that,
if a reversal of the judgment is a result of our reliance
on newly articulated standards, she is entitled to a new
trial so that she may have the opportunity to prove
her case under those standards. We conclude that the
requirement of an expert witness on the issue of
whether FM-37 emitted respirable asbestos fibers when
sanded was required under the law predating Bifolck
and Izzarelli and, therefore, that the plaintiff is not
entitled to a new trial.
   First, as to the plaintiff’s strict liability claim, it was
well established law at the time of trial that the plaintiff
was required to prove, inter alia, that the product at
issue ‘‘was in a defective condition unreasonably dan-
gerous to the consumer or user’’ and that the product’s
‘‘defect caused the injury for which compensation was
sought . . . .’’ (Internal quotation marks omitted.) Pot-
ter v. Chicago Pneumatic Tool Co., 241 Conn. 199, 214,
694 A.2d 1319 (1997). Additionally, a plaintiff could
prove the unreasonably dangerous requirement, as the
plaintiff in this case attempted to do, by showing that
the product was ‘‘dangerous to an extent beyond that
which would be contemplated by the ordinary con-
sumer who purchases it, with the ordinary knowledge
common to the community as to its characteristics.’’17
(Internal quotation marks omitted.) Id., 214–15. The
plaintiff was required to show, therefore, that FM-37
was dangerous because it emitted respirable asbestos
fibers when sanded and that FM-37’s emission of respi-
rable asbestos fibers caused the decedent to contract
mesothelioma. As we explain, the plaintiff failed to
do so.
   With respect to the plaintiff’s negligence claim, pursu-
ant to black letter principles, the plaintiff bore the bur-
den of proving that the defendant’s failure to test or
conduct research on FM-37 or to remove it from the
marketplace was unreasonable and was a legal cause
of the decedent’s mesothelioma. See, e.g., Murdock v.
Croughwell, 268 Conn. 559, 566, 848 A.2d 363 (2004)
(identifying essential elements of negligence action).
The plaintiff could not do this without showing that,
had the defendant performed testing or research, it
would have learned that sanding FM-37 emitted respira-
ble asbestos fibers; otherwise, the defendant’s lack of
testing or research would be of no consequence. Simi-
larly, the jury could not find that a failure to remove
FM-37 from the marketplace was unreasonable and that
it caused the decedent to develop mesothelioma unless
the plaintiff proved that, under ordinary use, FM-37
would emit dangerous, respirable asbestos fibers. See,
e.g., Johnson v. Newell, 160 Conn. 269, 273–74, 278 A.2d
776 (1971) (to recover in negligence action for selling
dangerous and defective tire without having properly
inspected it, plaintiff was required ‘‘to have proved a
defect in the condition of the tire’’).
   In sum, proof that FM-37 emitted respirable asbestos
fibers was essential for the plaintiff to prevail on either
of her theories of recovery under well established law
that existed at the time of trial. Such proof required
the assistance of an expert because the subject matter
was technical in nature and beyond the field of ordinary
knowledge of a lay juror. Because the plaintiff did not
produce an expert, she failed to prove her case.
  The judgment is reversed and the case is remanded
with direction to grant the defendant’s motion to set
aside the verdict and for judgment notwithstanding
the verdict.
   In this opinion the other justices concurred.
   * This case originally was scheduled to be argued before a panel of this
court consisting of Justices Palmer, Eveleigh, McDonald, Espinosa and Rob-
inson. Although Justice Espinosa was not present when the case was argued
before the court, she has read the briefs and appendices, and listened to a
recording of the oral argument prior to participating in this decision.
   The listing of justices reflects their seniority status on this court as of
the date of oral argument.
   1
     This action was commenced in 2012 and originally named more than
fifty defendants. By the time of trial, however, Wyeth Holdings Corporation
was the sole remaining defendant and it is the only defendant who remains
a party to this appeal. All references herein to the defendant are to Wyeth
Holdings Corporation.
   2
     The defendant appealed to the Appellate Court, and we transferred the
appeal to this court pursuant to General Statutes § 51-199 (c) and Practice
Book § 65-1.
   3
     The action originally was brought by both Wayne Bagley, to recover for
his personal injuries, and Marianne Bagley, to recover for loss of consortium.
After Wayne Bagley died, Marianne Bagley, in her capacity as executrix of
Wayne Bagley’s estate, was substituted as plaintiff as to the claims alleged
by him. See General Statutes § 52-555. For simplicity, we refer to Marianne
Bagley as the plaintiff both in her individual capacity and in her capacity
as Wayne Bagley’s executrix.
   4
     Sikorsky was permitted to intervene as a plaintiff in this matter but did
not participate in the trial proceedings and is not a party to this appeal.
   5
     More accurately, FM-37 was manufactured by American Cyanamid Cor-
poration. The defendant is a successor corporation to that entity.
   6
     The plaintiff also raised a strict liability claim based on the defendant’s
alleged failure to warn adequately of the dangerousness of FM-37. See Gen-
eral Statutes § 52-572q. In response to interrogatories, however, the jury
found that, although the defendant failed to provide adequate warnings or
instructions concerning FM-37, the lack of such warnings did not cause the
decedent to contract mesothelioma. The plaintiff has not challenged this
finding on appeal.
   7
     The plaintiff also claimed that the defendant was negligent in failing to
ensure that FM-37 carried adequate warnings. In light of the jury’s adverse
findings on the plaintiff’s strict liability failure to warn claim, it is apparent
that the plaintiff necessarily did not prevail on her negligent failure to warn
claim. See footnote 6 of this opinion. In any event, this claim is not an issue
in this appeal.
   8
     The record contains a packet of materials provided to Abraham in Janu-
ary, 2012. Those materials include a pathology report and slide, medical
records and the decedent’s answers to interrogatories, which describe, in
relevant part, his occupational history. They do not include any materials
or other information pertaining to FM-37 or any testing or analysis thereof.
   9
     The defendant did publish certain exhibits to the jury. They consisted
of medical records containing notes that indicated that the decedent had
told medical providers that he had not been exposed directly to asbestos.
   10
      The plaintiff contends that the defendant failed to preserve its claim
that, in order to prove negligence, she needed to show that FM-37 was
unreasonably dangerous. In its motion for a directed verdict, the defendant
argued generally that expert testimony was necessary to prove product
dangerousness and causation as required by the act. At that point in the
proceedings, the defendant disputed the viability of a separate cause of
action for negligence, contending instead that, under the act, all claims are
merged into a single, statutory product liability cause of action. The trial
court rejected that claim, however, and the defendant, in its subsequent
motion to set aside the verdict and for judgment notwithstanding the verdict,
then argued that the evidence was insufficient to support either theory of
recovery, specifically that, as to each theory, the plaintiff had failed to prove
both product dangerousness and causation. Under the circumstances, we
disagree that the defendant has waived its claim as it pertains to negligence
or that the plaintiff has been subject to an ambuscade.
   11
      The defendant also claims that the plaintiff improperly was permitted
to prevail on a ‘‘no-threshold’’ or ‘‘single fiber’’ theory of causation that is
contrary to Connecticut’s law governing proximate cause. Because we agree
with the defendant’s other arguments, which are dispositive of the appeal,
we need not reach this claim.
   12
      ‘‘Common knowledge is limited, however, to those well substantiated
facts that are obvious to the general community.’’ State v. Padua, 273 Conn.
138, 193, 869 A.2d 192 (2005) (Katz, J., dissenting and concurring). Common
knowledge is defined as a ‘‘fact that is so widely known that a court may
accept it as true without proof.’’ Black’s Law Dictionary (10th Ed. 2014) p.
334. In contrast, a matter is not common knowledge if it ‘‘involves obscure
and abstruse . . . factors such that the ordinary layman cannot reasonably
possess well-founded knowledge of the matter and could only indulge in
speculation in making a finding . . . .’’ (Emphasis omitted; internal quota-
tion marks omitted.) State v. Padua, supra, 200 (Katz, J., dissenting and con-
curring).
   13
      But see John Crane, Inc. v. Linkus, 190 Md. App. 217, 225–26, 241, 988
A.2d 511 (2010) (holding, in case in which evidence showed that claimant
was directly exposed for seven years to large amounts of dust from defen-
dant’s dry rope and wicking products that contained 60 to 90 percent unen-
capsulated asbestos, that expert testimony was not necessary to prove
release of respirable asbestos fibers).
   14
      A recent federal product liability case is particularly illustrative, given
the type of product at issue in the present case. In Dugas v. 3M Co., Docket
No. 3:14-cv-1096-J-39JBT, 2016 WL 3965953, *1–3 (M.D. Fla. June 22, 2016),
the plaintiff alleged that the decedent had contracted mesothelioma due to
his exposure to asbestos from the defendant’s epoxy adhesive, which was
used in the repair of naval aircraft. The decedent had testified that, after
the product was applied and had dried, he would sand and file it, creating
a dusty environment. Id., *3. The defendant moved for summary judgment,
contending that there was no evidence the decedent had inhaled asbestos
fibers released from the adhesive. Id., *6. The United States District Court
for the Middle District of Florida denied the defendant’s motion in light of
the fact that, one day earlier, it had ruled, over the defendant’s objections,
that certain expert testimony proffered by the plaintiff on the contested
issue was admissible. Id. The court allowed, however, that prior to the
admissibility ruling, the defendant’s position was ‘‘understandable.’’ Id.
   The court’s published ruling on the admissibility of the expert’s opinion
provides an example of the type of evidence that the plaintiff in the present
case might have introduced. See Dugas v. 3M Co., Docket No. 3:14-cv-
1096-J-39JBT, 2016 WL 3946802 (M.D. Fla. June 21, 2016). Specifically, the
plaintiff’s expert conducted experiments in which he attempted to recreate
the product and to test it under work practices similar to those utilized by
the decedent in that case. Id., *3. The ruling also makes reference to a study
conducted by the manufacturer of the product contemporaneous with its
use that demonstrated the different amounts of asbestos fibers that were
released when it was sanded, with and without local exhaust. Id., *4 and n.4.
   The arguments advanced in that ruling suggest that fiber release may be
affected by the composition of the product, the temperature at which it is
cured, the grit of the sandpaper used and the speed of the sander. Id., *3–6.
This further illustrates the need for evidence of fiber release that is directed
at a particular product or class of similar products. See Borg-Warner Corp.
v. Flores, 232 S.W.3d 765, 773 (Tex. 2007) (requiring defendant-specific
evidence of asbestos exposure, recognizing that proof of causation can differ
across products depending on whether asbestos is embedded or friable and
noting that ‘‘all asbestos products cannot be lumped together in determining
their dangerousness’’ [internal quotation marks omitted]); see also Marshall
v. Celotex Corp., 651 F. Supp. 389, 393 (E.D. Mich. 1987) (The court refused
to adopt the market share theory of liability, which was developed for
fungible products, because ‘‘[a]sbestos products . . . have widely divergent
toxicities, with some asbestos products presenting a much greater risk of
harm than others. . . . This divergence is caused by a combination of fac-
tors, including: the specific type of asbestos fiber incorporated into the
product; the physical properties of the product itself; [and] the percentage
of asbestos used in the product.’’ [Internal quotation marks omitted.]).
   15
      ‘‘Under the rules of evidence, [a]n expert may testify in the form of an
opinion and give reasons therefor, provided sufficient facts are shown as
the foundation for the expert’s opinion. Conn. Code Evid. § 7-4 (a). An expert
may have personal knowledge of the underlying facts or may obtain the
requisite information by attending the trial and hearing the factual testimony.
C. Tait, Connecticut Evidence [(4th Ed. 2008)] § 7.91, p. [429]. . . . Finally,
an expert may obtain information at trial by having factual testimony summa-
rized in the form of a hypothetical question at trial. Id.; Conn. Code Evid.
§ 7-4 (c).’’ (Citations omitted; internal quotation marks omitted.) Viera v.
Cohen, 283 Conn. 412, 444, 927 A.2d 843 (2007). It is established, however,
that, ‘‘on direct examination, the stated assumptions on which a hypothetical
question is based must be the essential facts established by the evidence.’’
(Internal quotation marks omitted.) Id., 449; see Graybill v. Plant, 138 Conn.
397, 403, 85 A.2d 238 (1951); see also Conn. Code Evid. § 7-4 (c) (1) (‘‘[a]n
expert may give an opinion in response to a hypothetical question provided
that the hypothetical question . . . presents the facts in such a manner that
they bear a true and fair relationship . . . to the evidence in the case’’).
   16
      In February, 2012, prior to trial, Abraham authored a brief report after
receiving case specific materials from the plaintiff’s counsel. Those materials
did not include any information pertaining to FM-37 or testing thereon. See
footnote 8 of this opinion. A cover letter accompanying the materials stated
that the decedent had been exposed to various asbestos containing products
while working at Sikorsky, and prefatory language in Abraham’s report
indicates that he relied on that assumption in arriving at his conclusions.
The report then describes Abraham’s interpretation of the pathology material
and sets forth Abraham’s opinion that the decedent has mesothelioma and
that, because mesothelioma is caused by asbestos and the decedent was
exposed to asbestos, the cause of his mesothelioma was the asbestos
exposure.
   17
      In Izzarelli v. R.J. Reynolds Tobacco Co., supra, 321 Conn. 172, we
clarified that the range of cases in which the consumer expectation test,
employed in the present case, would be appropriate is narrow, and that a
risk-benefit test, which requires consideration of additional factors, is our
primary test for claims of design defects. See id., 202–203; see also Bifolck
v. Philip Morris, Inc., supra, 324 Conn. 415–16; id., 432 (renaming tests).
