In Blackwell v. Phelps Dodge Corp. (1984) 157 Cal.App.3d 372, the defendant sold sulfuric acid to McKesson Chemical Company, which shipped the acid to its plant in a tank car designed and owned by Union Tank. (Id. at p. 375.) During shipment, pressure built up in the tank car, and when the plaintiffs attempted to unload the tank car and transfer the acid to a storage tank, the acid escaped and came into contact with the plaintiffs. (Ibid.) The plaintiffs sued the seller of the acid, alleging the seller had a duty to warn them of the possible accumulation of pressure in the tank car and to provide instructions on how to unload it safely. (Id. at pp. 375-376.) The Blackwell court rejected the plaintiffs' theory and affirmed summary judgment for the defendant. (Blackwell, supra, 157 Cal.App.3d at pp. 377-380.) Citing Garman, the court explained that "while failure to warn may create liability for harm caused by use of an unreasonably dangerous product (Product Liability), that rule does not apply where it was not any unreasonably dangerous condition or feature of defendant's product which caused the injury." (Id. at p. 377.) The reason the seller of the acid bore no liability was because "it was not the product (acid) supplied by defendant, but the container (tank car) in which that product was shipped, which was allegedly defective for lack of warnings or instructions. Under these circumstances, defendant incurred no liability to plaintiffs for its failure to warn them of danger from formation of pressure in the acid allegedly caused by defective design of the tank car, or to instruct them on how safely to unload the acid from the tank." (Id. at p. 378.)