CORRECTED OPINION
Rachael Praytor appeals a judgment in favor of Ford Motor Company on the ground that she presented sufficient evidence of causation to defeat summary judgment. We affirm.
Factual Background
Praytor was involved in an automobile accident in which the air bag in her Ford Probe deployed. Some time after the accident, she began to suffer from sinusitis and asthma. Praytor filed suit against Ford Motor Company and Charlie Thomas Ford 1 alleging the sinusitis and asthma were caused by exposure to chemicals released when the air bag deployed. Ford filed a no-evidence motion for summary judgment on the ground that Praytor had not produced evidence of causation. Pray-tor responded by attaching the affidavits of her experts, Dr. Alex Lechín, and Byron Bloch. Ford objected to Praytor’s affidavits contending the experts did not meet the requirements of Rule 702 of the Texas Rules of Evidence. Neither party requested a Robinsofir-Daubert hearing prior to the trial court’s ruling on the motion for summary judgment. The trial court granted summary judgment in favor of Ford stating, “Plaintiff has not produced legally competent evidence regarding causation, an essential element of her case.”
*241 Standard of Review
The “no-evidence” motion for summary judgment shifts the burden of proof to the non-movant to produce evidence raising a genuine issue of material fact on the contested issue on which the non-movant would bear the burden of proof at trial.
See
Tex.R. Civ. P. 166a(i). In this motion, a party asserts there is no evidence of one or more essential elements of claims upon which the opposing party would have the burden of proof at trial.
Lake Charles Harbor and Terminal Dist. v. Bd. of Trs. of Galveston Wharves,
Summary judgment is appropriate if the only evidence offered to prove an essential element of the claim cannot be given weight by the court.
W. Wendell Hall, Standards of Review in Texas,
29 St. Mary’s L. 351, 419 (1988). The non-mov-ant may not rely on evidence that is barred from consideration by rules of law or evidence, or that amounts to no more than a scintilla.
Id.
A non-movant presents less than a scintilla of evidence when that which is proffered is “so weak as to do no more than create a mere surmise or suspicion” — the effect being that there is no evidence offered.
Hight v. Dublin Veterinary Clinic,
Necessity of Expert Testimony
Praytor claims the facts established by her summary judgment evidence were sufficient to raise a fact question on causation for several reasons. First, Pray-tor contends that rule 702 does not apply because lay testimony is adequate to prove causation. To establish causation, a plaintiff must prove the defendant’s conduct caused an event and that event caused the plaintiff to suffer compensable damages.
Burroughs Wellcome Co. v. Crye,
Here, Dr. Lechín testified in his deposition that there can be several causes of sinusitis and asthma and that the diagnosis of their cause depends on the individual. General experience and common sense do not enable a fair understanding of causation under these circumstances; accordingly, expert testimony is required.
See Leitch v. Hornsby,
Waiver of Rule 702 Requirements
Second, Praytor contends Ford waived its complaint that her expert affida
*242
vits were inadmissible by failing to obtain a ruling in the trial court. In support of her waiver argument, Praytor relies on
Rogers v. Continental Airlines, Inc.,
Here, Praytor carried the burden to produce competent summary judgment evidence. Consequently, her reliance on
Dolcefino
and
Rogers
is misplaced.
See Weiss,
Rule 702 Challenge in the No-Evidence Summary Judgment Context
Rule 702 contains three requirements for the admission of expert testimony: (1) the witness must be qualified; (2) the proposed testimony must be scientific knowledge; and (3) the testimony must assist the trier of fact to understand the evidence or to determine a fact in issue.
E.I. du Pont de Nemours and Co., Inc., v. Robinson,
The trial court must make the preliminary decision regarding the expert’s qualifications under Rule 104(a).
Gammill v. Jack Williams Chevrolet, Inc.,
Praytor offered affidavits from two experts, Dr. Alex Lechín and Byron Bloch. Dr. Lechín is a medical doctor, board certified in pulmonary medicine. In *243 his affidavit, he states that he reviewed medical literature concerning exposure to the chemicals released by air bag deployment. Lechín admitted in his deposition that he is not an expert on asthma, the causes of asthma, or whether deployment of an air bag can cause asthma. Further, Lechín does not purport to be an expert on the toxicity of chemicals released when an air bag deploys. Dr. Lechin’s medical expertise is greater than that of the general population, but Praytor did not establish that his expertise on the issue of cause in fact met the requisites of Rule 702.
Similarly, there is sound basis for the trial court to conclude that Byron Bloch is not qualified to render an opinion on whether deployment of the air bag caused Praytor’s respiratory symptoms. Bloch stated, in his affidavit, that he is an independent consultant on automotive safety design and vehicle crashworthiness. He has been qualified and given testimony as an expert in matters pertaining to defective automobiles. Further, Bloch is familiar with the air bag system that was in the automobile owned by Praytor. Bloch, however, professes no knowledge of the possible causes of respiratory illness.
We acknowledge the difficult circumstance Praytor faces in fulfilling requirements for presentation of expert testimony under rule 702. However, we are constrained to render our decision solely on the summary evidence presented in response to Ford’s no-evidence motion for summary judgment. Accordingly, we hold the trial court did not abuse its discretion if it found that Praytor’s experts were not qualified.
In addition to qualification of an expert witness, rule 702 requires that the proposed testimony must be relevant and rehable.
Robinson,
In addition to the relevancy requirement, the underlying scientific technique or principle must be rehable. Expert testimony that is not grounded in methods and procedures acknowledged by scientists in the particular field of study amount to no more than subjective belief or unsupported speculation.
Daubert v. Merrell Dow Pharmaceuticals, Inc.,
1. the extent to which the theory has been tested;
2. the extent to which the technique relies on the expert’s subjective interpretation;
3. whether the theory has been subject to peer review;
4. the technique’s potential rate of error;
5. whether the underlying theory or technique has been generally accepted as valid by the relevant scientific community; and
6. the nonjudicial uses that have been made of the theory or technique.
*244
Robinson,
With regard to whether a plaintiffs injury was caused by exposure to a particular substance, a plaintiff generally must prove both that the substance is capable of causing a particular injury or condition and that the substance in fact caused the plaintiffs injury.
Havner,
In his affidavit, Dr. Lechín averred that he was Praytor’s treating physician. After reviewing medical literature concerning exposure to chemicals released in air bag deployment, he determined that Praytor’s asthma and sinusitis were caused by her exposure to chemicals released when the air bag deployed. A treating physician’s assertion that a physical examination confirmed causation should not be accepted at face value.
Havner,
Praytor claims she has produced evidence of causation by showing a temporal relationship between her exposure to the toxic chemical and the onset of her symptoms. For this proposition, appellant cites
Westberry v. Gislaved Gummi AB,
Differential diagnosis, or differential etiology, is a standard scientific technique of identifying the cause of a medical problem by eliminating the likely causes until the most probable one is isolated.
See Baker v. Dalkon Shield Claimants Trust,
Praytor also cites
Kennedy v. Collagen Corp.,
Here, Dr. Lechín did not rule out other potential causes for Praytor’s illnesses, nor did he rely on peer-reviewed articles, clinical trials, health department investigations, or appellant’s laboratory tests. For the above stated reasons, we hold that the trial court did not abuse its discretion if it concluded that Dr. Lechin’s testimony does not present reliable evidence of causation.
In his affidavit, Bloch stated that the Ford air bag system “was unreasonably dangerous and was defective in that there was a release of toxic materials, primarily sodium azide and hydrazoic acid gas and sodium hydroxide, that were the likely proximate cause of the respiratory injuries to Rachael Praytor.” In forming his opinion, Bloch relied on a description of the air bag system, the air bag inflator process and chemicals, information provided by Ford, and the nature of the injuries incurred by Praytor. Bloch relied on a publication by the National Research Council, of the National Academy of Sciences, which stated: “The acute toxicity of sodium azide is high. Symptoms of exposure include lowered blood pressure, headache, hypothermia, and in the case of serious overexposure, convulsions and death. Ingestion of 100 to 200 mg in humans may result in headaches, respiratory distress, and diarrhea.”
Reviewing the Robinson factors, we find Bloch’s theory has not been tested, nor subjected to peer review. Further, there is no indication that Bloch’s technique has been generally accepted as valid by the relevant scientific community.
Praytor contends Bloch’s opinion is reliable because there is no analytical gap in his logic.
See Gammill,
Praytor further contends Bloch’s opinion is rehable because it is based on a physician’s opinion that chemicals from the air bag caused the symptoms. In Bloch’s affidavit, there is a statement from Dr. Bradford Patt, one of Praytor’s treating physicians. Dr. Patt stated that Praytor had been healthy prior to the accident; however, she experienced severe blockage of her sinuses after the accident. Dr. Patt further stated:
It would be hard to know whether an air bag exposure to chemicals would be the cause, or should I say that it would be difficult to document this. However, in an otherwise healthy patient, which Rachael reportedly was before this event, the most likely cause is an aspiration of some type into her sinuses and lungs of the chemical at the time of the accident.
Dr. Patt’s opinion is similar to the opinion expressed by Dr. Lechín. It is based on temporal proximity of symptoms to the air bag explosion. For the reasons mentioned above, we hold the trial court did not abuse its discretion if it concluded that Dr. Patt’s opinion is not reliable.
Conclusion
We recognize that a no evidence motion for summary judgment presents potential pitfalls for non-movants when the issue is reliability of expert testimony. A non-movant responding to a no-evidence motion for summary judgment may request a continuance of the summary judgment proceeding in order to submit additional evidence. The non-movant may also request a Robinson-Daubert hearing in order to overcome the reliability challenge. See Judge David Hittner & Lynne Liberato, Summary Judgments in Texas, 34 Hous. L.Rev. 1303, 1348 (1998). We do not have the benefit of a record reflecting the basis for the trial court’s ruling on the qualifications and methodology of Praytor’s experts prior to the summary judgment hearing. Consequently, we must review admissibility of the experts’ opinions based solely on the summary judgment evidence.
Under this record, we hold that the trial court did not abuse its discretion if it concluded that Praytor’s experts are not qualified and their opinions are not reliable. Because Praytor relied on evidence that is barred from consideration by the rules of evidence, the trial court did not err in granting summary judgment. The judgment of the trial court is affirmed.
Notes
. Appellant later non-suited Charlie Thomas Ford, Inc.
