In litigation arising out of a chemical release at a plant, the Trial Court ordered Relator Kuraray America, Inc., the defendant below, to produce cell-phone data from the employer-issued phones of five employees. Two of the five employees are supervisors—for them, the trial court ordered production of cell-phone data for the six-week period before the chemical release. As to the remaining three employees—control-room board operators who reported to the two supervisors—the trial court ordered production of cell-phone data for the four-month period before the release.

The Texas Supreme Court granted Mandamus:

“Quite unsurprisingly, discovery requests for cell-phone data have become commonplace in recent years. While our Court has not yet had occasion to apply the legal principles governing discovery in this context, our courts of appeals have grappled with the issue. From these cases, we glean some key principles that should guide trial courts’ careful management of cell-phone-data discovery. First, to be entitled to production of cell-phone data, the party seeking it must allege or provide some evidence of cell-phone use by the person whose data is sought at a time when it could have been a contributing cause of the incident on which the claim is based. If the party seeking the discovery satisfies this initial burden, the trial court may order production of cell-phone data, provided its temporal scope is tailored to encompass only the period in which cell-phone use could have contributed to the incident. In other words, a trial court may not, at this stage, order production of a person’s cell-phone data for a time at which his use of a cell phone could not have been a contributing cause of the incident. Only if this initial production indicates that cell-phone use could have contributed to the incident may a trial court consider whether additional discovery regarding cell-phone use beyond that timeframe may be relevant….

“We conclude that the trial court abused its discretion by ordering production of Kuraray’s employees’ cell-phone data for a six-week or four-month period without a showing that each employee’s use of his cell phone on May 18 or 19 could have been a contributing cause of the ethylene release. Plaintiffs’ petitions do not allege that cell-phone use by anyone was a contributing cause of the release. Instead, they assert in their motions to compel the general proposition that the release may have been caused by cell phone usage and abuse by board operators. Relying on this assertion, the trial court ordered Kuraray to produce four months of cell-phone data for the three board operators and six weeks for the supervisors. This was impermissibly overbroad.

“The question that discovery of cell-phone data is meant to answer in this case is whether any Kuraray employee was distracted by his cell phone at a time when he should have been taking action to prevent the release, such that his use of the cell phone reasonably could be found to be a contributing cause of the release. Plaintiffs do not dispute that the events to which they allege the employees should have been responding began, at the earliest, during the May 18 night shift, which started at 5:30 p.m. And Kuraray does not dispute that Plaintiffs are entitled to discover the board operators’ cell-phone data during on-duty hours from the start of that shift until the release occurred – approximately seventeen hours later. But the trial court instead ordered Kuraray to produce cell-phone data for far broader time periods: either four months preceding the release (in the case of the three board operators) or six weeks preceding the release (in the case of the two supervisors).

“Plaintiffs argue that cell-phone data from days, weeks, and months before the release is relevant because Kuraray negligently failed to supervise its employees and failed to implement adequate policies and procedures to protect against cell-phone misuse. But Kuraray’s policies regarding cell-phone use and its alleged failure to supervise its employees are relevant only if there is some evidence that cell-phone use could have been a contributing cause of the release itself. In the absence of such a showing, the employees’ earlier cell-phone usage, like Kuraray’s cell-phone policies and success or failure in enforcing them, is neither relevant nor discoverable.”


In re Kuraray America, 656 S.W.3d 137 (Tex. 2022).