--- title: "Industrial Hygiene Expert Not Allowed to Opine on Falling Debris" meta: "og:description": "The industrial hygiene expert was not allowed to testify about whether the hazard of falling debris should have been obvious" "og:title": "Industrial Hygiene Expert Not Allowed to Opine on Falling Debris" author: "Expert Witness Profiler" description: "The industrial hygiene expert was not allowed to testify about whether the hazard of falling debris should have been obvious" --- # Industrial Hygiene Expert Not Allowed to Opine on Falling Debris Posted on April 8, 2026 by Expert Witness Profiler Plaintiff Douglas Looney, Evergreen’s employee, was standing behind a vacuum truck to wash its interior when a chunk of ash flew out, injuring him. Defendant intended to present the expert testimony of [Jason Henthorn](https://expertwitnessprofiler.com/expert-witness/Jason-Henthorn/1555988) at trial. Plaintiffs asked the Court to exclude Henthorn’s testimony pursuant to [Federal Rule of Evidence 702](https://www.law.cornell.edu/rules/fre/rule_702#:~:text=Rule%20702%20sets%20forth%20the,is%20a%20relatively%20narrow%20inquiry.). ## **Industrial Hygiene Expert Witness** [Jason E. Henthorn](https://expertwitnessprofiler.com/expert-witness/Jason-Henthorn/1555988) has a bachelor’s degree in industrial hygiene. He also has experience creating and maintaining work safety programs, training employees on workplace safety, and investigating workplace accidents. [Get the full story on challenges to Jason Henthorn’s expert opinions and testimony with an in-depth Challenge Study](https://expertwitnessprofiler.com/order/add?eId=1555988&pId=3). ## **Discussion by the Court** #### **A. Opinion 1** The first opinion that Plaintiffs attacked is that “Looney placed himself in an area of increased risk when he positioned himself in between the half door and the truck’s debris body.” Plaintiffs argued that this opinion should be excluded because it is not based on “any identifiable hazard analysis” and because Henthorn never explained his methodology in reaching this conclusion. During his deposition, Henthorn testified he had experience with vacuum trucks similar to the one involved in Looney’s accident. Henthorn also suggested there were “materials in the operator’s manual of the truck” and “stickers or placards on the truck” alerting employees to the danger of standing behind the truck. Because Henthorn’s experience is sufficient to render the opinion reliable and helpful to a jury, the Court will not exclude this opinion. #### **B. Opinion 2** Henthorn’s second opinion is that Defendant “possessed policies and procedures, including the Vacuum Truck Safety Program, which originated in 2019 and had been revised a number of times.” As Plaintiff’s pointed out, this is simply a factual statement. Still, the Court decided that Henthorn’s perspective would be helpful to the jury; his experience will allow him to explain whether these policies and procedures apply to the work Looney was doing when he was injured. #### **C. Opinion 3** The third opinion at issue is that Defendant “did not possess knowledge of a dangerous condition or practice involving its vacuum trucks.” Plaintiffs argued that this opinion “is pure speculation.” The Court agreed. As Plaintiffs pointed out, “in his deposition, Henthorn could not identify the field supervisor who ordered Looney and his crew to decontaminate the vacuum truck on the day in question.” Further, Defendant’s own report on Looney’s accident contradicted Henthorn’s conclusion that Defendant lacked knowledge. #### **D. Opinion 4** Henthorn’s fourth opinion is that “the struck-by hazard of falling debris should have been obvious and apparent to Looney as he relocated himself during his work due to the ash not coming out of the truck as he had previously experienced.” During his deposition, Henthorn acknowledged that he had no experience with the type of material in the truck Looney was cleaning. He testified that he did not know what type of ash was in the truck, nor how long the ash had been sitting in the truck before Looney began cleaning it, but he explained that both the type of ash and the amount of time it had been sitting would affect its density. Given Henthorn’s lack of knowledge about the material in the truck, the Court held that he cannot reliably testify whether the hazard of falling debris should have been obvious to Looney. #### **E. Opinion 5** Finally, Henthorn opined that Defendant “did not violate a specific industry standard which caused Looney’s incident.” Henthorn’s experience in industrial hygiene made him qualified to explain which industry standards may or may not apply to a particular work activity and whether certain employer conduct violates an industry standard. In his deposition, he discussed specific industry standards and explained why, in his view, they did not apply on the day of the accident. As a result, the Court admitted this opinion. ## **Held** The Court granted in part and denied in part Plaintiffs’ motion to exclude the testimony of Jason Henthorn under Federal Rule of Evidence 702. ## **Key Takeaway** Some expert opinions are only reliable when supported by scientific testing. 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