
92 S.W.3d 605 (2002)
U.S. SILICA COMPANY, Appellant,
v.
Ruby L. TOMPKINS, Individually and as Executrix of the Estate of Donald L. Tompkins, Deceased, Sherri Lopez and Dawn Maldonado, Appellees.
No. 09-01-377 CV.
Court of Appeals of Texas, Beaumont.
Submitted June 13, 2002.
Decided November 21, 2002.
*607 C. Kelvin Adams, Jack E. Urquhart, Beirne, Maynard & Parsons, LLP, Houston, for appellant.
Daryl L. Moore, Sharon S. McCally, Storey, Moore & McCally, P.C., Houston, Guy G. Fisher, Provost & Umphrey, Beaumont, Lance Lubel, Robins, Cloud, Greenwood & Lubel, Helen A. Cassidy, Houston, for appellees.
Before WALKER, C.J., BURGESS and GAULTNEY, JJ.

OPINION
RONALD L. WALKER, Chief Justice.
U.S. Silica Company ("U.S. Silica"), formerly known as Pennsylvania Glass Sand Company ("PGS"), and the successor-in-interest to Ottawa Silica Company ("Ottawa"), appeals a judgment awarding Ruby L. Tompkins, Individually and as Executrix of the Estate of Donald L. Tompkins, Deceased, Sherri Lopez, and Dawn Maldonado, (collectively "The Tompkinses") damages for personal injuries resulting from Donald L. Tompkins's ("Tompkins") use of a silica product supplied by U.S. Silica Company or its predecessor corporation. U.S. Silica presents five issues in its appeal.
Issue one asks: "Was there legally and factually sufficient evidence that PGS's and Ottawa's marketing defect was a producing cause of Tompkins' silica-related injury?" Issue two asks: "Was there legally and factually sufficient evidence that PGS's and Ottawa's negligence (failure to warn) was a proximate cause of Tompkins' silica-related injury?" In these issues, the appellant challenges the jury's marketing defect and negligence findings.
Tompkins worked as an abrasive blaster, first for Newsome & Work Sandblasting Company ("Newsome") over a six-year period beginning in the 1960s then for Akron Sand Blasting ("ASB") for another six years in the 1970s, and finally for F.W. Gartner Company ("Gartner") in a six-year period in the 1980s.[1] Tompkins wore an *608 MSA brand air-fed hood while sandblasting for ASB and Newsome and wore a paper dust mask while cleaning up a site. Tompkins and his co-employees identified PGS and Ottawa as brands of sand used by Newsome and ASB during Tompkins's period of employment. During that period of time PGS and Ottawa did not place any silicosis warning labels on their bags of sand. By the time Tompkins worked for Gartner, virtually all companies in the sand industry had started warning. In the 1980s, Tompkins used sand provided by Pioneer, Lone Star, and Clemtex. The Lone Star sand used at Gartner was, to Tompkins's recollection, bulk sand. Lone Star's post-1976 Texblast bags stated: "Use only with government approved face mask. Warning: Contains free silica. Do not breathe dust. May cause delayed lung injury silicosis." Tompkins could not recall seeing labels on the bags of sand when he worked for Gartner.
In the absence of a warning, a rebuttable presumption arises that the user would have heeded the warning had one been provided. American Tobacco Co. v. Grinnell, 951 S.W.2d 420, 431 (Tex. 1997). The defendant may rebut the presumption with evidence that the plaintiff failed to heed whatever warnings were given, and would not have heeded any proposed warning. Id. Once the presumption is rebutted, the plaintiff must prove causation as in any other case. General Motors Corp. v. Saenz, 873 S.W.2d 353, 357 (Tex. 1993). The appellant contends there is no evidence that Tompkins would have heeded a warning had PGS and Ottawa placed one on the bags of sand sold for abrasive blasting because Tompkins did not notice the warnings placed on the sand bags that he used in the 1980s. Therefore, U.S. Silica argues, Tompkins would not have heeded warnings had they been provided in the 1960s and 1970s.
The appellant compares its case to Dresser Industries, Inc. v. Lee, 880 S.W.2d 750, 754 (Tex. 1993), a products liability silicosis case in which the Supreme Court held that a fact issue on the employer's negligence as sole cause of the injury was raised by evidence that the plaintiff seldom used a mask or respirator even though the dust in the improperly ventilated foundry bothered him so much that he had to spit. The appellant points to two factors that it claims serve to rebut the presumption that a warning would have been heeded by Tompkins. While employed by Newsome and ASB, Tompkins worked in a dusty working environment without air monitoring. And after warning labels were being utilized, Tompkins continued to use sand for abrasive blasting in dusty working conditions and with the same type of respiratory equipment. What U.S. Silica did not explain to the jury was why Tompkins should have realized that the safety precautions he was taking were inadequate to protect him from hazards connected to exposure to silica dust. In addition to the evidence that Tompkins wore safety equipment while working, Tompkins testified that if there had been warnings and he had not understood them, he would have inquired of them with his employer.
Tompkins's failure to notice the warnings printed on bags of sand in the 1980s bears on U.S. Silica's causation issues only if those warnings were noticeable and effective, but nevertheless were ignored by Tompkins. Although there is evidence of the wording of the warning that one supplier decided to place on its *609 sand bags, U.S. Silica does not identify the evidence presented to the jury that proved that the warning was noticeable. One witness, Behzad Samimi, testified that the warnings placed on bags of sand in the late seventies and early eighties were very fine print on huge bags and could barely be seen. The adequacy of a warning is a question of fact to be determined by the jury. Alm v. Aluminum Co. of America, 717 S.W.2d 588, 592 (Tex.1986). In this case, the warning in question is not one provided by the defendant, but by a supplier more than a decade after the exposure at issue in this case. Considering the circumstances of Tompkins's exposure and the paucity of evidence concerning the adequacy of the warnings provided in the 1980s, the jury reasonably could reject U.S. Silica's supposition that Tompkins would not have heeded an adequate warning had PGS or Ottawa provided one. We hold that the evidence is legally and factually sufficient that PGS's and Ottawa's marketing defect was a producing cause of Tompkins's silica-related injury. We further hold that the evidence is legally and factually sufficient that PGS's and Ottawa's negligence in failing to warn Tompkins was a proximate cause of Tompkins's silica-related injury. Issues one and two are overruled.
Issue three asks this Court to adopt and apply the "sophisticated user" and "intermediary" doctrines to excuse PGS and Ottawa from warning Tompkins of the hazards of using silica in abrasive sandblasting. A similar argument was rejected in Humble Sand & Gravel, Inc. v. Gomez, 48 S.W.3d 487 (Tex.App.-Texarkana 2001, pet. granted), which is currently under submission before the Texas Supreme Court. U.S. Silica suggests that we should adopt the dissent in Humble Sand and hold that U.S. Silica's predecessor corporations had no duty to warn Tompkins of the silicosis hazard inherent in the use of their products for abrasive sandblasting. We decline to adopt the Humble Sand dissent in this case, because Tompkins's employers were not sophisticated intermediary users in the sense that the employer in Humble Sand might have been.
Newsome had seven employees in 1967, and 15 employees at its peak. It performed sandblasting for utility companies. During Tompkins's tenure, ASB grew from 25 to 40 employees. It, too, performed professional sandblasting. Neither had any type of training school or safety manuals.
The appellant contends that Tompkins's employers, Newsome and ASB, were members of an industry, sandblasting, in which the dangers of silica were well known. Other than the fact that both companies provided safety equipment for their abrasive blasters, however, the record reveals little evidence of Newsome's and ASB's actual awareness of that danger while Tompkins was employed by them. U.S. Silica refers to two witnesses who were employed by Tompkins's employers: Roger Newsome and John Lee Cooper. Roger Newsome, the son of one of the original owners of Newsome, testified that as a high school senior in 1970 he began working as a general laborer for Newsome. He learned that exposure to silica could be harmful to one's health at that time; his father told him to keep his mask on because "sand is bad for you." The elder Newsome did not tell him about invisible particles or mention anything specific about the hazards. The younger Newsome had been told that he needed to wear an air-fed hood when he blasted, but he did not think that he had to wear it when he was not blasting. No written information was handed down to employees. There was no written protection program in place.
*610 John Lee Cooper, who began working for ASB in September 1967 as a sandblaster, testified that he was aware of the dangers of sandblasting when he started working for ASB because he had been warned by his mother that silica sand was dangerous. When he started working, however, he was not aware that silica sand could be disabling. He became aware of that danger from the big warnings printed on every bag. Cooper could not recall ever receiving any written safety materials from 1967 to 1980, and to his knowledge there was not a person assigned to safety there, although he did recall that ASB had safety meetings in the 1980s.
In 1976, a date some time after Tompkins began employment there, PGS sent ASB a copy of the OSHA voluntary guidelines for occupational exposure to crystalline silica in abrasive blasting and a copy of an OSHA Material Safety Data Sheet that included the statement, "Repeated inhalation of respirable dust for extended period of time may cause injury to the lungs." PGS sent the guidelines to all of its customers. The witness who testified regarding these communications was Richard Day, who had been PGS's general counsel since 1974 and who implemented their warnings program in 1977. Day did not know what Tompkins's employers knew at the time Tompkins worked for them as a sandblaster. He admitted that his company did no study to determine what its customers knew about the health hazards related to sandblasting. The appellees, on the other hand, refer to findings made by Dr. Samimi at the conclusion of a study he conducted for Boeing Aerospace Company. According to Samimi, the study concluded that the purchasers of sand did not even know about the hazards of sand and the necessity for respiratory devices.
The appellant's argument, that it owed no duty to Tompkins because his employers were sophisticated intermediaries who could be reasonably expected to protect their employees from the hazards of the use of silica sand in abrasive blasting, does not withstand close scrutiny. In the alternative, U.S. Silica argues that it was entitled to a jury instruction on the issue. It requested two such instructions. One would have told the jury: "PGS and Ottawa were not required to give warnings if they reasonably believed, at the time Donald Tompkins used the product, that his employers knew of the products' dangers and would protect his employees." The other provided: "PGS and Ottawa were not required to give warnings or instructions if Donald Tompkins' employers knew or, in the exercise of ordinary care, should have known of the products' dangers at the time Donald Tompkins used the product and warned or, in the exercise of ordinary care, should have warned Donald Tompkins of the products' dangers." The appellees contend that these instructions were unnecessary surplusage. We agree. The trial court wields considerable discretion in deciding what instructions are necessary and proper in submitting issues to the jury. State Farm Lloyds v. Nicolau, 951 S.W.2d 444, 451 (Tex.1997). Here, the trial court instructed the jury that, if an act or omission of any person not a party to the suit was the sole cause of the injury, then no act, omission, or product of any party to the suit could have been a cause of the injury. The trial court also instructed the jury that adequate warnings and instructions mean warnings and instructions given in a form that could reasonably be expected to catch the attention of a reasonably prudent person in the circumstance of the product's use. Naturally, the jury would not be called upon to determine whether the producers of the sand had a duty to Tompkins, only whether *611 the defendants breached that duty and whether the breach of that duty caused the injury in question.
Certainly there was no duty to warn about risks associated with a product that were matters "within the ordinary knowledge common to the community." See Joseph E. Seagram & Sons, Inc. v. McGuire, 814 S.W.2d 385, 388 (Tex.1991); Caterpillar, Inc. v. Shears, 911 S.W.2d 379, 382 (Tex.1995). Here the jury was further instructed that a failure to warn constituted a "marketing defect" if the "failure rendered the product unreasonably dangerous as marketed"; and "unreasonably dangerous" was defined as "dangerous to an extent beyond that which could be contemplated by the ordinary user of the product with the ordinary knowledge common to the community as to the products' characteristics." (emphasis added).
Any factual issues to be resolved by the jury concerning the appellant's sophisticated intermediary theory could be, and were, presented to the jury through the broad-form causation instructions. U.S. Silica's requests were not reasonably necessary to enable the jury to render a proper verdict.
Also in issue three, in a single paragraph, U.S. Silica also argues that the trial court erred in excluding from evidence trade and scientific articles offered for the limited purpose of showing knowledge in the abrasive blasting industry regarding the hazards of silica dust. Assuming the trial court erred in excluding this evidence, the error is harmless because that knowledge was not connected to Tompkins's employers and is not shown to be other than cumulative. Tex.R.App. P. 44.1. Issue three is overruled.
In its fourth issue, U.S. Silica contends that the plaintiffs failed to exclude smoking as a cause of Tompkins's emphysema and death. Citing Merrell Dow Pharmaceuticals, Inc. v. Havner, 953 S.W.2d 706, 714 (Tex.1997), and E.I. du Pont de Nemours & Co. v. Robinson, 923 S.W.2d 549 (Tex.1995), the appellant contends that, in order to satisfy their burden of proof, the plaintiffs must exclude with reasonable certainty plausible causes of death other than silicosis. The Tompkins's medical experts agreed that smoking contributed to the emphysema that killed Donald Tompkins. Therefore, U.S. Silica reasons, appellees failed to prove that Tompkins's silica-related injury was a producing cause and proximate cause of his injury and death.
The act of the defendant need not be the sole cause of an injury. There may be more than one producing cause or proximate cause of an injury. Haynes & Boone v. Bowser Bouldin, Ltd., 896 S.W.2d 179, 182 (Tex.1995); Wilson v. Brister, 982 S.W.2d 42, 44 (Tex.App.-Houston [1st Dist.] 1998, pet. denied). Dr. Gary Friedman testified that Tompkins died from the complications of silicosis and chronic obstructive pulmonary disease. According to Dr. Friedman, "part of the COPD is due to silicosis and some of it is due to smoking." Tompkins had, in his estimation, one of the most severe pulmonary impairments in a person with his smoking history. The doctor identified characteristics in Tompkins's lungs that were classic for silicosis and not for smoking. Smoking, he testified, does not cause confluence or firm nodular lesions. Dr. Jerrold Abraham, a pathologist, testified that, in reasonable medical probability, exposure to silica was a cause of Tompkins developing emphysema. In his opinion, smoking was also a major cause of Tompkins's emphysema, but Tompkins "had more emphysema because of his silica exposure than he would have had just from smoking." According to Dr. Abraham, "his lung was impaired by his combination of silicosis and emphysema and that silica *612 contributed to both of those so that he ran out of functioning lung because of those diseases[,] because of that silica exposure[,] sooner than he would have had he not had them, had he not had the silica exposure."
U.S. Silica adduced expert testimony that Tompkins suffered from severe panlobular emphysema in 90% to 100% of his lungs, and mild simple silicosis in 5% to 7% of his lungs. Its pathologist testified that Tompkins's scarring emphysema from his silicosis accounted for only 5% of his emphysema, and would not change his lung function or life expectancy. In reviewing the record, we find that both parties presented extensive expert evidence and medical evidence to support the experts' opinions. As the sole judge of the credibility of the witnesses and the weight to be given their testimony, the jury could accept or reject either theory. The record clearly indicates that there was both legally and factually sufficient evidence presented to sustain the plaintiffs' burden of proof on causation. Issue four is overruled.
Issue five urges the trial court erred in excluding from evidence a CT scan report and testimony interpreting that report. On October 30, 2000, Tompkins had a high resolution CT scan taken of his lungs. Dr. Bill Kistler, a radiologist, reviewed the scan report and prepared a report interpreting it. A regular CT scan had been performed a few days earlier, and Dr. Kistler's report referred to this earlier date, but he was sure that he reviewed a complete high-resolution scan because that was what he reported. Dr. Kistler's report states that he found no evidence of interstitial fibrosis. The scan was ordered by the plaintiffs' expert, Dr. Gary Friedman, who was not a treating physician. Dr. Friedman suggested the scan because a July 2000 x-ray indicated the presence of a nodular mass on the lung. The scans were apparently lost by the hospital and never sent to Dr. Friedman, who noticed the report for the first time when he prepared for his deposition. Dr. Friedman contacted the treating physician, who decided not to retake the test because there had been no change in the suspected area between July and December, Tompkins was already hospitalized, and his condition was so grave that it would not have made a difference. According to Dr. Friedman, Dr. Kistler could not confirm that the scan was Tompkins's and failed to perform the scan according to his instructions or standard protocol, and mishandling of the films by the hospital resulted in their being lost. Dr. Friedman concluded that Dr. Kistler's report was unreliable, incorrect, and inconsistent with the radiologic and pathologic evidence, and merited no consideration by any party.
At trial, U.S. Silica argued that the excluded evidence was relevant to the issue of the disease process. The trial court's denial of the defendant's tender was, according to the Tompkinses, within the court's discretion because it was so unreliable as to be irrelevant. We disagree. The absence of evidence of interstitial fibrosis on the scan was relevant to the extent of Tompkins's impairment from silicosis. The attendant circumstances went to the weight of the evidence rather than its admissibility. We hold that the trial court erred in excluding Dr. Kistler's report.
Having found error, we must determine whether the error complained of probably caused the rendition of an improper judgment. Tex.R.App. P. 44.1(a)(1). We must review the entire record in order to determine whether the whole case turned on the excluded evidence. City of Brownsville v. Alvarado, 897 S.W.2d 750, 753-54 (Tex.1995). U.S. Silica argues that the CAT scan was a more accurate depiction *613 of Tompkins's condition during his life than the numerous x-rays that the experts interpreted for the jury. The Tompkinses argue that the error would be harmless because the pathologists for both the plaintiff and the defense found silicosis to be present in Tompkins's lungs and, confirmed the radiologic evidence and clinical evidence.
Dr. Kistler explained that the interpretation of the x-rays could simply be mistaken, because the CT is a more accurate depiction of actual pathology than x-rays, and the pathologists autopsy reports could have detected interstitial fibrosis that the CT could not detect. Thus, the evidence would have been helpful to the jury in determining the extent of Tompkins's silicosis. However, in this case the parties' experts had available to them the actual lungs for analysis and formation of their expert opinions. Dr. Friedman did not rely on the scan or on Dr. Kistler's report in forming his expert opinion because he could not confirm their reliability. None of the experts who testified relied on the CT scan or on Dr. Kistler's report in forming a medical opinion. Dr. Kistler's report was subject to serious attack on its reliability that substantially affected its weight. U.S. Silica's pathologist, Dr. Francis Green, testified that Tompkins had mild chronic silicosis in five to seven percent of his lungs, that would not impair his lung function or life expectancy. Thus, the excluded evidence was cumulative of other, stronger, evidence submitted to the jury. Issue five is overruled. The judgment is affirmed.
AFFIRMED.
NOTES
[1]  These dates are approximate. The jury heard conflicting evidence on exact dates of Tompkins's employment. This evidence supports a conclusion that no silicosis warnings were provided to Tompkins by U.S. Silica's predecessors. We also note that Tompkins worked as a sandblaster for McDermott Industries in between his employment with Newsome and ASB. Since neither party mentions this fact in its brief, we will assume it lacks significance.
