Humble Sand & Gravel, Inc. v. Gomez

delivered the opinion of the Court,

Generally, a product supplier must warn expected users of foreseeable risks that make the product unreasonably dangerous,1 but a supplier need not warn of risks that are common knowledge,2 and when the product is supplied through an intermediary, a supplier may sometimes rely on the intermediary to warn the actual product users.3 We must apply these basic principles to the circumstances presented in this case. Specifically, the issue is whether a supplier of flint used for abrasive blasting had a duty to warn its customers’ employees that inhalation of silica dust can be fatal and that they should *173wear air-supplied protective hoods, given the customers’ knowledge of those dangers.

If the flint supplier in this case had such a duty, it is only because all similarly situated flint suppliers have the same duty, not because of some peculiar aspect of this one defendant’s situation. Therefore, to determine whether a general legal duty exists, we must look beyond the particular circumstances of the injury here complained of, just as the parties themselves have done, to the broader industrial setting in which that injury occurred. The record before us establishes that by the 1980s, the dangers of using flint in abrasive blasting had been well known throughout the abrasive blasting industry as well as to health and safety professionals and government regulators for most of the twentieth century, but that blasting workers themselves remained largely ignorant of those dangers, and their employers were careless in enforcing workplace conditions that would protect workers’ safety. The record also reflects that federal regulations have been imposed on employers to improve working conditions but not on flint manufacturers to warn of dangers involved in the use of their product. While the parties here no longer dispute that such a warning by the defendant supplier would have prevented the plaintiffs injury, missing from this record is any evidence that, in general, warnings by flint suppliers could effectively reach their customers’ employees actually engaged in abrasive blasting. Without such evidence, we are unable to determine whether a duty to warn should be imposed on flint suppliers. Consequently, we reverse the judgment of the court of appeals4 and, in the interest of justice, remand the case to the trial court for a new trial.

I

Raymond Gomez contracted silicosis while working at and around abrasive blasting (often but less accurately called sandblasting) for about 6½ years, from 1984-1987 and again from 1991-1994, at plants in Odessa, where he was born and raised, and in Corpus Christi, where his wife was from. In 1995, Gomez filed suit in Jefferson County against more than twenty defendants, including four suppliers of flint used as the abrasive in the blasting work, two suppliers of blasting equipment, thirteen suppliers of protective gear worn by workers, and several jobsite owners. Gomez settled with all of the defendants except Humble Sand & Gravel Company, one of the flint suppliers, for a total of $389,200, and then following a jury trial obtained a judgment against Humble for about $2 million. Much of the evidence relevant to the issues now before us was undisputed at trial, but where it was conflicting, we of course recite that which was most favorable to Gomez.

Gomez left school after the ninth grade because his wife was pregnant with their first child. Within the year, at age 18, he started work for Spincote Plastic Coating Co. in Odessa, where he stayed six months before moving to Corpus Christi to work at Spincote’s plant there for three years. Spincote was in the business of using abrasive blasting to clean and condition oilfield tubing. This involved spraying steel tubing with particles of flint shot through a nozzle with compressed air under pressures around 100 p.s.i. Flint is very hard stone composed mostly of crystalline silica (silica dioxide (Si02), commonly called quartz), which in its natural, undisturbed state is not at all dangerous. But when flint particles are blasted against metal at high pressure, they not only scorn’ and *174abrade the surface, they shatter into an airborne dust of smaller particles. Some of this dust is coarse enough to rebound against workers, injuring exposed skin, and to hang in the air, obscuring visibility. But some particles of free silica are so fíne — 5 microns (or about 200 millionths of an inch) in diameter, something like l/20th the diameter of a human hair — as to be invisible to the naked eye. The visible dust can clog the nose and mouth but is too coarse to be inhaled into the lungs and is relatively harmless. But the microscopic particles of free silica are both respira-ble and toxic. Inhaled over months or years, free silica particles cause silicosis, an incurable disease involving a fibrosis and scarring of the lungs and other complications that can eventually result in disability and death. Silicosis is caused only by inhaling free silica. Inhalation of free silica particles cannot be prevented by ordinary, loose-fitting, disposable paper masks; the particles are too small. People working around silica dust must wear air-fed hoods or respirators covering their heads or faces to protect themselves.

The parties here agree, and the record establishes, that the health risks from inhaling silica dust have been well known for a very long time. One of Gomez’s expert witnesses, Dr. Eula Bingham, former Assistant Secretary of Labor in charge of the Occupational Safety and Health Administration (OSHA) from 1977-1981, observed that Hippocrates (460-377 B.C.) linked respiratory disease to mining and stone-masonry, and that the first systematic treatise on occupational disease, De Mor-bis Artificum, written by Bernardino Ra-mazzini in 1700, identified silicosis as a pneumoconiosis (“a disease of the lungs caused by the habitual inhalation of irritant ... particles”5) common to stonemasons. Dr. Bingham and another of Gomez’s expert witnesses, Dr. Vernon Rose, a certified industrial hygienist, testified that for more than 300 years silicosis has been treated as an occupational disease of flint knappers — workers who chip flint into desired shapes, such as gunflints.6 The chipping releases free silica particles into the air. Both Dr. Bingham and Dr. Rose testified that the link between silicosis and abrasive blasting using silica flint was firmly established by physicians and public health officials in the United States and Europe in the early twentieth century.

A tragedy in the 1930s forced the attention of this nation and others to the dangers of silicosis. While constructing Hawk’s Nest Tunnel through a mountain near Gauley Bridge, West Virginia, workers dug three miles through rock formations rich in silica. Hundreds died from silicosis and were buried nearby in unmarked graves, as Congressional hearings afterward revealed.7 Several years later, according to Dr. Bingham, England banned the use of silica in abrasive blasting, and over time other European countries followed suit. Since these events, Dr. Bingham affirmed, it has been “well known throughout the medical and industrial worlds that [silicosis] is an occupational disease” associated with abrasive blasting. Dr. Rose agreed that “[t]his indisputable body of knowledge has been out there for all of industry and employers in the industrial workplace to know for a long time”.

Studies of the health hazards of abrasive blasting with flint also determined that such work could be done relatively safely if *175workers were required to use suitable air line respirators- — devices that fit over the face or head with a clean air supply for workers to breathe. Dr. Bingham and Dr. Rose testified that the American National Standards Institute, a consensus group made up of various industry participants including manufacturers, suppliers, employers, unions, and customers, first adopted safety standards calling for the use of respirators in abrasive blasting in 1938. OSHA regulations for abrasive blasting originally promulgated in the early 1970s also require the use of respirators, or air-fed hoods, “constructed [to] cover the wearer’s head, neck, and shoulders to protect him from rebounding abrasive.” 8 These regulations also require employers to develop written procedures for selecting respirators, to instruct employees in their use, to keep respirators clean and well-maintained, and to conduct frequent random inspections to ensure employee compliance.9 Given these safety standards and regulations and the long-held concerns that led to their adoption, Dr. Rose testified that one “would expect a professional in ... the abrasive blasting industry to know about the hazards of abrasive blasting” and “the requirements to provide air-supplied respiratory equipment to the workers”. Frank Bogran, a witness called by Gomez, who had run a major abrasive blasting business since 1962, agreed that “[b]y 1975 the people that were in that sandblasting industry, they knew about the hazards” and “knew about the need to wear proper air-fed equipment”.

But their employees usually did not. The widespread knowledge of the dangers of silica dust produced by abrasive blasting and the necessity of wearing proper protective equipment was not often shared by the ordinary workers themselves or their supervisors and did not translate into safety in the workplace. It is undisputed on the record before us that the dangers of silicosis frequently went unheeded in practice. In 1974, the National Institute for Occupational Safety and Health sponsored a survey conducted by Boeing Aerospace Co. of some 400 businesses across the country “to determine the degree of respiratory protection currently afforded workers in industries which employ abrasive blasting techniques”. The survey found the condition of respiratory equipment “generally deplorable”. In many workplaces, respirators were ill-fitting, not cleaned or maintained, not supplied with clean air, or not regularly used by employees, and management was often “unaware of the inadequacy of their equipment.” The survey report observed:

The average firm safety man, where one exists — and this is usually a duty in addition to some normal “productive” function — seems unaware of the problems of respirable dust and noise.

The average blaster seems unconcerned by equipment deficiencies. His trade has always been dusty and noisy.

The report concluded that—

the persons responsible for selecting abrasive blasting respiratory protective equipment [for blasting workers] are none too informed nor interested in the subject. Their concern is with abrasive blasting per se and not with safety measures. A serious education effort is indicated.

Another study, begun at Tulane University’s Medical Department in the early 1970s, showed that sandblasting in the Louisiana shipyards and on offshore drill*176ing platforms occurred under similar conditions. The problems identified in these studies, according to Dr. Rose, were “pretty typical” throughout the industry in the 1970s and 1980s and were “occurring all over the country”.

Humble, a relatively small, family-owned and -operated business with eight employees located in Picher, Oklahoma, began packaging and selling flint for abrasive blasting in 1982. Humble processed flint from chat (crushed rock) piles left over from World War II zinc-mining operations. Humble sold flint both in bulk and in 100-pound bags, and only to industrial customers. From the beginning, Ron Humble, who ran the business with his father, knew that breathing the silica dust generated by abrasive blasting could cause silicosis and that the disease could be fatal. He also knew that he should put some sort of warning label on the bags,10 and after making inquiries of OSHA and a trade organization that yielded him no useful information, he decided to copy the following label used by a competitor, Independent Gravel, who he understood had been in business for more than fifty years:

WARNING!

MAY BE INJURIOUS TO HEALTH IP PROPER PROTECTIVE EQUIPMENT IS NOT USED.

Frank Bogran testified that his business had used a similar warning on bags it sold beginning in 1972, deliberately omitting to state that the health injury referred to could be death. Humble added a Spanish version in 1986 (at Spincote’s request) and a French version (for Canadian customers) sometime later. In 1993, Humble began using the following more extensive warning on its bags:

WARNING

BREATHING DUST OF THIS PRODUCT CAUSES SILICOSIS, A SERIOUSLY DISABLING AND FATAL LUNG DISEASE.

AN APPROVED AND WELL-MAINTAINED AIR-SUPPLIED ABRASIVE BLASTING HOOD MUST BE WORN AT ALL TIMES WHILE HANDLING AND USING THIS PRODUCT.

FOLLOW ALL APPLICABLE OSHA STANDARDS.

Ron Humble testified that he had known all of the additional details in this warning since 1982 but had not included them earlier because he had simply copied Independent Gravel’s warning.

Dr. Bingham and Dr. Rose approved of this latter warning but criticized the earlier one in the following two respects. First, the earlier warning understated the risk of inhaling silica dust by stating only that it “may be injurious to health” and not that it may result in disability and death. Second, the earlier warning did not specify that the only “proper protective equipment” was an air-fed hood, allowing the mistaken notion that other equipment, like disposable paper masks, would do as well.

In addition to the warning on its bags, Humble provided its customers a Material Safety Data Sheet (MSDS) as required by OSHA regulations.11 The regulations prescribed the categories of information to be included but did not specify the information itself, so Humble again copied a form *177used by Independent Gravel. The form included the following subcategories (on the left) and information supplied by Humble (on the right):

[[Image here]]

Abrasive blast personnel should use only approved respirators Emergency and First Aid Procedures

Silica Dust Hazardous Decomposition Products

Approved Respirator Respiratory Protection

Yes — with air hood Eye Protection

The MSDS, according to Dr. Bingham and Dr. Rose, suffered the same dual inadequacies as the bag label: it failed to emphasize the severity of the health hazard— that it could be fatal — and failed to specify that the respirator used should not just be “approved” but air-fed.

Humble also provided its customers with a sales leaflet it called a “technical fact sheet”. Listed among its product’s “important advantages” was: “Extremely low break-down rate, allowing material to be used over several times.” Dr. Bingham and Dr. Rose criticized this encouragement of reuse because each time flint is used, more particles are broken down to respirable size, thereby posing a greater danger to workers.

Humble sold flint to Spincote for abrasive blasting at its Odessa and Corpus Christi plants. Although the record does not reflect the size of either plant, Dr. Rose testified that he understood Spincote was a subsidiary of ICO, Inc., a company with some 1,400 employees in Texas, California, Wyoming, and Oklahoma. Ken Gray, the general manager of the Spincote subsidiary in 1984, testified by deposition at trial. He acknowledged that it was Spincote’s obligation to be aware of safety requirements, to provide a safe working environment including proper respiratory equipment, and to train its employees in safety procedures. He testified that he relied on applicable regulations for safety information and not on any supplier’s warning label or MSDS. But Gray also testified that in 1982, when he took over Spincote, he did not know that inhaling silica dust could cause silicosis; he knew only that silica dust was a nuisance and that breathing it was not healthy. He had himself, he said, walked through the dusty blasting building as often as twice a day without wearing any respiratory protection at all. As for when it was that he learned of regulations relating to abrasive blasting and that inhaling silica dust could result in silicosis and death, Gray expressed considerable uncertainty, indicating at various points that it was in the early 1980s, the mid-1980s, and maybe as late as December 1986. Gray did not know for sure whether Spincote’s employees were ever told that inhaling silica dust could be fatal.

Eldon “Shorty” Workman, the Odessa plant manager in 1984, also testified at trial by deposition. He stated that he had worked in abrasive blasting in the 1950s and 1960s and that while he had always worn an air-fed hood, he had not become fully aware of the dangers of silicosis until after he had worked as a blaster for several years. By the time he became Spin-cote’s plant manager he understood that breathing silica dust could lead to silicosis, an incurable lung disease, and death, and that it was his responsibility to provide employees with this information. He testified that Spincote’s blasting employees were required to wear air-fed hoods, were reprimanded if they failed to do so, and were fired after three violations. Employees who worked around the dust but were *178not actually operating blasting nozzles were only required to wear paper masks, not hoods. Workman was not asked why, if he was fully aware of the dangers, he did not require everyone working around the dust to wear hoods at all times. He stated that employees were required to attend regular safety meetings where they were warned of the dangers of silica dust and instructed in the use of protective equipment. Like Gray, however, Workman could not say definitely whether employees were ever told that inhaling silica dust could be fatal.

Abrasive blasting at Spincote’s plants was done inside a building in, an area called the blast house. Gomez was hired to work as an “end grinder”, a job that did not involve blasting but was performed in the dusty environment of the building. Gomez was given only a disposable paper mask that was held against his face with rubber bands. After his first month, Gomez was moved to “end cutter”, a job that did involve blasting. At that point, he was provided an air-fed hood in addition to the paper mask and was shown how to use the hood properly. The hood, he said, slipped over his head and fit like a turtleneck around his neck. It had an air supply hose that attached to the top and clear plastic front shields to see through that could be replaced as they became dirty. Gomez testified that the hoods he wore were not torn, did not allow dust inside, and were always in good condition. Humble offered testimony from one of Gomez’s former coworkers that Spincote’s hoods were torn, in bad condition, and dusty inside. But Gomez insisted that he never had any problems with his hood. He stated that he disassembled and washed it every week with soap and water..

However, Gomez and his former coworker agreed that when blasting stopped for breaks during or at the end of a shift, employees had to remove their hoods to leave the blast house, even though the áir was still dusty, because the hoses supplying air to the hoods would not reach past the immediate work area. Gomez also testified that he did not wear a hood when cleaning up the blast house, which involved shoveling back into the blasting machine’s flint supply pot dust that had accumulated knee- and waist-deep. This activity stirred the dust, including free silica particles, back up into the air. Gray acknowledged that Spincote had twice been cited for excessive free silica particles in the work environment, and Gomez was exposed to them whenever he removed his hood and mask, even if the blasting had stopped.

At the end of each shift, according to Gomez, the workers would haul bags of flint from where they were stacked over to the blast area and empty them , into the supply pot on the blasting machine. There is no evidence that this process generated free silica particles requiring workers to wear protective gear. Although Humble sold flint to some customers in bulk, the flint it sold to Spincote was always in 100-pound bags. Spincote also bought flint from other suppliers, some of which was in bags. Gomez testified that the first time he saw Humble’s bags, he noticed the warning label and asked his foreman about it. His foreman replied that as long as he wore his hood and mask he would be all right. Gomez thought the phrase on the label, “injurious to health”, meant that dust rebounding off blasted surfaces could hurt when it struck the skin and was bad to breathe. The hood, he thought, was for protection from the flying dust and the paper mask was to prevent inhalation. Still, he thought, the dust was, ordinary dust, like what he might sweep out of his garage. He did not know that the dust contained invisible free silica particles too fine to be screened by a paper mask. Go*179mez also saw the following warning label on another supplier’s bags:

WARNING: CONTAINS FREE SILICA. DO NOT BREATHE DUST. May Cause Delayed Lung Injury, (Silicosis). Follow OSHA Safety and Health Standards for Crystalline Silica (Quartz).

But Gomez testified that he did not ask his foreman about this warning and did not know what silicosis was. He did not know that silicosis or inhalation of free silica particles could lead to disability and death. Gomez testified that had he known how dangerous silica dust was, he never would have taken or kept a job working around it.

After Gomez left Spincote’s Corpus Christi plant in 1987, he returned home to Odessa and did not work as an abrasive blaster again until 1991, when he went to work for Sivalls, Inc., another Odessa business. The blasting he did there was done outside on larger objects, but otherwise the work was much the same. There, as at Spincote, he testified he always wore his hood and mask when blasting but not at other times when he was around dust.

In November 1994, Gomez sought medical treatment for shortness of breath, and within a few days he was diagnosed as having subacute silicosis. A biopsy of his lung tissue confirmed that he had had a high exposure to silica dust. He left work at Sivalls and was never again employed in abrasive blasting. When Gomez’s action against Humble went to trial nearly five years later in 1999, he had become licensed as a barber. Dr. Gary Friedman, board certified in internal medicine and occupational medicine, testified that while Gomez had suffered as yet few symptoms and no impairment, silicosis is a progressive disease, and given the extent and duration of his exposure, Gomez could expect significant disability within eight years and full disability within fifteen years. Dr. Friedman testified that a person with silicosis is also more susceptible to other respiratory diseases including tuberculosis, to autoimmune diseases including arthritis, and perhaps even to cancer. Dr. Friedman believed that Gomez, then 38, had a life expectancy of 20-25 years.

The trial court admitted evidence that Spincote and Sivalls used flint purchased from suppliers besides Humble, but it excluded Gomez’s admissions, made in response to a discovery request, that other flint suppliers and equipment manufacturers and distributors that he had sued were responsible for his injury. The jury was asked only about Humble’s and Gomez’s responsibility. The jury found that Gomez’s injury had been caused by a marketing defect in its flint, based on the following definitions taken verbatim from the Texas Pattern Jury Charges:

A “marketing defect” with respect to the product means the failure to give adequate warnings of the product’s dangers that were known or by the application of reasonably developed human skill and foresight should have been known or failure to give adequate instructions to avoid such dangers, which failure rendered the product unreasonably dangerous as marketed.

“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 circumstances of the product’s use; and the content of the warnings and instructions must be comprehensible to the average user and must convey a fair indication of the nature and extent of the danger and how to avoid it to the mind of a reasonably prudent person.

*180An “unreasonably dangerous” product is one that is dangerous to an extent beyond that which would be contemplated by the ordinary user of the product with the ordinary knowledge common to the community as to the product’s characteristics.12

The jury also found that Gomez’s injury was caused by Humble’s unspecified negligence but did not find that it was caused by his own negligence. The jury assessed the following damages: past physical pain, $5,000; future physical pain, $300,000; past mental anguish, $5,000; future mental anguish, $300,000; past lost wages, $18,000; future lost earning capacity, $500,000; future disfigurement, $10,000; future physical impairment, $500,000; past medical care, $17,000; and future medical care, $150,000. The jury also assessed $50,000 damages for each of Gomez’s two children’s future loss of parental consortium. The trial court rendered judgment on the verdict, excluding credits and including interest, for $2,053,058.76 for Gomez and $54,672.07 for each of his children.

On appeal, Humble did not challenge the jury’s liability findings, including the inadequacy of its warning of the dangers of using flint in abrasive blasting. Rather, Humble argued that it had no duty to warn of those dangers because they were well known in the abrasive blasting industry, Humble sold only to industrial customers, and it was entitled to rely on them to provide their own employees, like Gomez, with all necessary information. A divided court of appeals rejected Humble’s argument and affirmed the district court’s judgment.13

We granted Humble’s petition for review.14 Two months later Gomez’s counsel filed a suggestion of his death, the date and cause unstated.15 We proceed as if Gomez remained a party to the appeal.16

II

Humble argues here, as it did in the court of appeals, that a product supplier has no duty to warn its customers’ employees of the risks of using the product if the customers should already know of those risks and are themselves obliged by law to warn their own employees. Awareness of risks, Humble contends, must be determined objectively in the context of the industry or business involved — what an ordinary person in that situation should know, not what one person or another actually does know. Humble argues that these issues should all be matters of law to be determined by the court, but that if they are matters of fact, then it was entitled to jury findings, which it requested and was denied. Humble also complains that it was not allowed to offer evidence at trial that Spincote intentionally caused, and other suppliers and products may have caused, Gomez’s injury.

Gomez argues that regardless of anything Spincote should have done, Humble had a duty to warn him of two things: that inhaling silica dust could lead to disability and death, and that an air-fed hood should be worn around silica dust at all times. Employers like Spincote, Gomez contends, could not be relied on to provide these warnings. Regarding the exclusion of evi*181dence of which Humble complains, Gomez argues that any error was harmless.

The jury found Humble hable under two separate legal theories: products liability and negligence. Although the jury’s finding did not specify how Humble had been negligent, the only evidence of negligence that caused Gomez’s injury was that Humble failed to adequately warn of the dangers of using flint in abrasive blasting. (There is no evidence, for example, that Humble’s encouragement of the reuse of its product, though negligent, caused Gomez’s injury.) Thus, the factual basis for liability under both theories was the same. While both legal theories impose, in certain circumstances, a duty on a supplier to warn of dangers in its product’s use, the theories are not identical. Products liability focuses on the product; negligence focuses on the supplier’s conduct.17 We need not consider here any ramifications of the differences between the two theories because Gomez does not argue that Humble had a duty under one theory different from the duty under the other theory.18 Therefore, we assume for present purposes that Humble’s obligations under both theories are co-extensive.

It is firmly established in Texas that the existence and elements of a common law duty are ordinarily legal issues for the court to decide, whether the duty (for products liability) is not to distribute a defective product19 or (for negligence) to act with ordinary care.20 Not long ago we explained:

*182In deciding whether to impose a com-monlaw duty, this Court has applied the familiar factors identified in Graff v. Beard, 858 S.W.2d 918, 920 (Tex.1993), Greater Houston Transportation Co. v. Phillips, 801 S.W.2d 523, 525 (Tex.1990), and Otis Engineering Corp. v. Clark, 668 S.W.2d 307, 309 (Tex.1983). The considerations include social, economic, and political questions and their application to the facts at hand. We have weighed the risk, foreseeability, and likelihood of injury against the social utility of the actor’s conduct, the magnitude of the burden of guarding against the injury, and the consequences of placing the burden on the defendant. Also among the considerations are whether one party would generally have superior knowledge of the risk or a right to control the actor who caused the harm.21

We have recognized, however, that in some instances these issues may turn on facts that cannot be determined as a matter of law and must instead be resolved by the factfinder,22 although we have actually identified only one such instance. Under the Federal Employers’ Liability Act,23 a railroad’s duty to protect its employees from injury is measured by the foreseeability of harm, and while the issue of “whether a legal duty exists, including the foreseeability element, is typically a legal question [in FELA actions in Texas courts24] ..., if the essential facts about foreseeability as an element of the railroad’s duty are disputed, the question is a fact issue for the jury.”25 We have had no other opportunity to consider the interplay of factual and legal determinations in deciding whether a duty exists and if so, what its parameters are.

Nor have we had occasion to consider how the burden of proving facts related to the existence of a duty should be assigned when those facts are in dispute. As a general rule, the plaintiff must establish the existence of a duty;26 the burden is not on the defendant to show that it had no duty. Consistent with that rule, when the foreseeability of harm is an element of *183duty and factually disputed, as in the instance just mentioned, we have put the burden of proof on the plaintiff.27 In this case, however, as will be seen, we must more carefully consider the application of the general rule.

Humble’s argument has two components: one, it had no duty to warn its customers of the risks of working around silica dust because those risks were common knowledge in the abrasive blasting industry long before 1984; and two, it had no duty to warn its customers’ employees of those risks because its customers were in a better position to warn their own employees. If the risks of silica dust were not commonly known in the industry, then Humble had at least a duty to warn its customers, which Gomez argues Humble did not do. Even if the risks were commonly known, the question remains whether Humble still had a duty to warn its customers’ employees. We consider each component of Humble’s argument in turn.

Ill

A supplier has no duty to warn of risks involved in a product’s use that are commonly known to foreseeable users, even if some users are not aware of them.28 “Commonly” does not mean universally. “Commonly known” means “ ‘beyond dispute’ ”.29 As we have said, “the inquiry whether a recognition of risk ‘is within the ordinary knowledge common to the community’ is an objective standard.”30 Thus, for example, in Joseph E. Seagram & Sons, Inc. v. McGuire, we concluded that “[f]rom ancient times, the danger of alcoholism from prolonged and excessive consumption of alcoholic beverages has been widely known and recognized” and is thus “common knowledge among the public”, even though the plaintiffs in that case asserted that they were themselves personally unaware of this danger.31 But in American Tobacco v. Grinnell, we concluded that while the general health risks of smoking were common knowledge, the specific risk of addiction continued to be disputed by the tobacco industry itself and thus could not be said to be common knowledge among smokers.32 When the foreseeable users of a product have special training, a supplier has no duty to warn of risks that should be obvious to them, even if persons without such training would not appreciate the risks. For example, in Sander Custom Fabrication, Inc. v. Boyd, we held that a scaffolding supplier had no duty to warn a boilermaker of the risk of falling because “[n]o ordinary person trained to do the work [he] and his crew were doing could have failed to appreciate the obvious risk”.33 What level of appreciation amounts to common knowledge is to be determined by the court as a matter of law unless there are factual issues that must be resolved.34

*184With these principles in mind, we turn to the present case. Over fifty years ago, the United States Supreme Court observed: “ ‘It is a matter of common knowledge that it is injurious to the lungs and dangerous to health to work in silica dust, a fact which defendant [a railroad, the injured worker’s employer] was bound to know.’ ”35 Over ten years ago this Court noted: “Inhaling silica dust may cause respiratory disease, a risk that has been recognized for more than a century”.36 Consistent with these general observations, the record before us in this case establishes, and the parties do not disagree, that as a matter of objective fact, the general dangers of inhaling silica dust, including disability and death, and of not wearing air-fed hoods to protect against inhalation, have been common knowledge among flint suppliers and abrasive blasting operators for decades and were certainly so in 1984 when Gomez went to work for Spincote.37 Humble admittedly knew of these dangers in 1982 when it began selling flint, and there is evidence that Spin-cote’s Odessa plant foreman, Workman, knew of them as well, having worked for many years in the abrasive blasting industry.

The evidence that operators like Spin-cote were often careless in conducting abrasive blasting and insufficiently motivated to provide for the safety of their workers does not ascribe their indifference to inadequate warnings by flint suppliers. On the contrary, the evidence is that operators neglected safety despite their knowledge of the seriousness of silicosis and the standards, industrial and legal, for abrasive blasting. The 1974 Boeing and Tulane studies showed that operators were unaware, not of the serious dangers of working around silica dust or the need for protective equipment, but of the proper use of that equipment in the workplace— assuring that it fit tightly, was regularly cleaned and maintained, was supplied with clean air, and was routinely worn by employees. Gomez does not contend that flint suppliers should or could have instructed operators or workers in the proper use of protective equipment. The two warnings Gomez does contend Humble should have given were of dangers well known, though largely unheeded, in the abrasive blasting industry.

At the same time, it is equally well established on this record that the dangers of silica dust were not generally known to workers like Gomez employed in abrasive blasting operations. Workman, Spincote’s foreman, testified that he had worked as a blaster for years before learning of the danger of silicosis. Gomez testified that when he first saw that word, he did not know what it meant. Gomez thought silica dust was like the dust he swept out of his garage. His and Workman’s experiences were typical of the industry workforce.

From this record we conclude that flint suppliers like Humble had no duty to warn its customers like Spincote and Sivalls, abrasive blasting operators, that inhaling silica dust can be disabling and fatal and that workers must wear air-fed hoods, because that information had long been commonly known throughout the industry. Blasting operators’ disregard of the risks to their employees of inhaling silica dust *185was not for want of additional information that flint suppliers should have furnished, but for want of care. We turn, then, to the question whether Humble had a duty to warn its customers’ employees, who were not generally aware of the risks.

IV

A

In Alm v. Aluminum Co. of America, we recognized that “a manufacturer or supplier may, in certain situations, depend on an intermediary to communicate a warning to the ultimate user of a product.”38 Aim claimed that an aluminum cap had popped off a soda bottle and struck him in the eye. Alcoa manufactured the machine that fastened the cap to the bottle top, and Aim claimed Alcoa should have warned him of the risk that a cap could pop off. But the machine Alcoa manufactured was owned and operated by an independent bottler. Alcoa did not control the bottling process or sell the bottled soft drink and had no practical way of reaching consumers with any warning. In that situation, we said, “Alcoa should be able to satisfy its duty to warn consumers by proving that its intermediary [the bottler] was adequately trained and warned, familiar with the propensities of the product, and capable of passing on a warning.” 39 We analogized Alcoa’s position to that of a bulk supplier of material that is repackaged and sold and who thus has no means of providing the ultimate consumer with a warning about risks of use.40 In a different vein, we noted that other courts had held that a pharmaceutical manufacturer is not required to warn patients of the dangers of a prescription drug as long as physicians who prescribe the drug— “learned intermediaries” — have been adequately warned.41 In both situations, we said, it would be reasonable for the supplier to rely on the intermediary to warn the ultimate consumer. But we cautioned that—

the mere presence of an intermediary does not excuse the manufacturer from warning those whom it should reasonably expect to be endangered by the use of its product. The issue in every case is whether the original manufacturer has a reasonable assurance that its warning will reach those endangered by the use of its product.42

We concluded that while Alcoa had no duty to warn Aim directly, it did have a duty to warn the bottler and had failed to do so adequately.

Gomez argues that just as Alcoa failed to adequately warn the bottler, the intermediary between Alcoa and the ultimate consumers, Humble failed to adequately warn the employer/operator intermediaries between it and abrasive blasting workers. Gomez notes that the jury found Humble’s warning inadequate, period, not just to Gomez. But any deficit in Humble’s warnings to Spincote and Sivalls is inconsequential, since we have concluded that Humble had no duty to warn them at all because the risks of using flint that Gomez contends should have been warned about were common knowledge in them industry. In Aim, there was no argument that the risks of harm from caps misapplied by Alcoa’s machine were common knowledge in the bottling industry. Alcoa had a duty to warn bottlers of the risks of use of its *186machine even though it had no duty to warn consumers. Humble is in the opposite position: it had no duty to warn abrasive-blasting operators of the risks of harm involved in abrasive blasting but may have had a duty to warn their employees, the end users of its product.

Aim cited but did not discuss section 388 of the Restatement (Second) of Torts, which sets out a rule similar to the one applied in Aim:

One who supplies directly or through a third person a chattel for another to use is subject to liability to those whom the supplier should expect to use the chattel ... if the supplier

(a) knows or has reason to know that the chattel is or is likely to be dangerous for the use for which it is supplied, and

(b) has no reason to believe that those for whose use the chattel is supplied will realize its dangerous condition, and

(c) fails to exercise reasonable care to inform them of its dangerous condition or of the facts which make it likely to be dangerous.43

A product supplier’s responsibility under section 388 may extend only to its customers, or it may reach its customers’ employees. If section 388 governed the present case and were applied literally, Humble would clearly have had no duty to warn Gomez because the record disproves the second element, (b): Humble had every reason to believe that Spincote knew of the dangers of using flint in abrasive blasting, since they were common knowledge in the industry, and at least some reason to believe that Spincote would communicate its knowledge to Gomez, since it was required by law to do so, even though many such operators did not warn their employees. It cannot fairly be said that Humble had no reason to believe that abrasive blasting workers would be told the dangers of silica dust. Humble and amici curiae44 argue that this should be the end of our analysis.

We think the argument is much too broad. Spincote’s legal obligation to warn Gomez, Humble contends, derived partly from an employer’s common law duty to warn employees of the hazards of their employment.45 Were this common law duty, shared by all employers, enough to justify Humble’s reliance on Spincote to warn its employees, no supplier would ever be required to warn its customers’ employees of product risks of which its customers should have been aware. Warning an employer intermediary would always be good enough, and our discussion of the appropriateness of such á warning in Aim would have been unnecessary. We have been cited no authority for such a blanket exemption from the general duty to warn the ultimate users of a product of dangers involved in its use, and we are aware of none. Humble argues that in addition to its common law responsibility, Spincote had more specific legal obligations toward its employees — those imposed by detailed OSHA regulations on all abrasive blasting operators. But these regulations were neither so customarily followed nor so rig*187idly enforced that flint suppliers could thereby reasonably expect workers to be mindful of the dangers of silica dust. Indeed, on the record before us the opposite is true. Accordingly, we are not persuaded that this case can be decided using the literal language of section 388.

The black-letter rule of section 388 seriously understates the subtlety of the matter, as comment n to the provision, which we quote at length, elaborates:

Chattels are often supplied for the use of others, although the chattels or the permission to use them are not given directly to those for whose use they are supplied, as when a wholesale dealer sells to a retailer goods which are obviously to be used by the persons purchasing them from him, or when a contractor furnishes the scaffoldings or other appliances which his subcontractor and the latter’s servants are to use, or when an automobile is lent for the borrower to use for the conveyance of his family and friends. In all such cases the question may arise as to whether the person supplying the chattel is exercising that reasonable care, which he owes to those who are to use it, by informing the third person through whom the chattel is supplied of its actual character.

Giving to the third person through whom the chattel is supplied all the information necessary to its safe use is not in all cases sufficient to reheve the supplier from liability. It is merely a means by which this information is to be conveyed to those who are to use the chattel. The question remains whether this method gives a reasonable assurance that the information will reach those whose safety depends upon their having it. All sorts of chattels may be supplied for the use of others, through all sorts of third persons and under an infinite variety of circumstances. This being true, it is obviously impossible to state in advance any set of rules which will automatically determine in all cases whether one supplying a chattel for the use of others through a third person has satisfied his duty to those who are to use the chattel by informing the third person of the dangerous character of the chattel, or of the precautions which must be exercised in using it in order to make its use safe. There are, however, certain factors which are important in determining this question. There is necessarily some chance that