UPDATED: Wednesday, August 17, at 3:23 p.m. The metal lathe that killed Michele Dufault ’11 in a Sterling Chemical Laboratory machine shop April 13 lacked federally-mandated safeguards, and Yale failed to uphold several safety measures in the machine shop, an Occupational Safety and Health Administration investigation has found.

Because Dufault was not an employee of the University, Yale will not face fines from OSHA, Area Director Robert Kowalski wrote in a letter sent Monday to University General Counsel Dorothy Robinson. The OSHA investigation could not determine specific hazards to employee safety, but investigators still issued seven recommendations for improving machine shop safety at Yale.

Although OSHA determined that the University had erred in several ways, Yale alleged that many of the agency’s findings are based on faulty information.

“Yale has reviewed OSHA’s letter regarding its investigation of the accident, a letter which apparently was shared first by the agency with the media. Unfortunately, OSHA’s assessment contains a number of significant inaccuracies,” University spokesman Tom Conroy said in an email to the News Tuesday evening.

The OSHA letter clarified that the lathe’s rotating “lead screw” was central to the accident. OSHA investigators found no physical guarding, personal protective equipment or emergency stops on the machine that killed Dufault.

According to the agency’s letter, federal law requires a shop operator to provide external safeguards for a lead screw that is completely exposed without protection. But Conroy said the lathe in question met all American National Standards Institute regulations, which incorporate both training and personal protective equipment.

OSHA also found that Yale had erred in several other ways: Site safety inspections and audits of the shop conducted by the University did not address machine safeguarding, and the shop did not post any general rules and regulations — including caution signs — for using the lathe or any of the other equipment in the room.

Kowalski also wrote in his OSHA letter that he recommends that Yale “develop and implement a formal training program (including a course outline, curriculum and training records) that meets the requirements of all ANSI standards.” But Conroy said the implication that Yale undergraduates did not receive proper training is false.

“Machine tool training provided by Yale was extensive, consistently reinforced by professional staff, and confirmed by Yale’s expert to be exemplary,” he said, adding that “students were repeatedly instructed not to use machinery without a buddy present.”

During its investigation, OSHA identified the machine as a Harrison-Claussing lathe manufactured in 1962. According to the letter, the University could not determine when the machine had been purchased, but faculty confirmed the equipment had been at the facility since at least 2000 in interviews with OSHA staff.

After Dufault’s accident, OSHA investigators were not immediately sure if the lab fell under their jurisdiction because Dufault was a student, said OSHA spokesman Ted Fitzgerald. But because University employees also use the machine shop in question, he said, the agency began an investigation. OSHA’s mission is to enforce safety standards for employees in the workplace.

“If there was a possibility there was hazard that might affect employees, then we would want to look into it,” Fitzgerald said in April.

Following the incident, Yale administrators pledged to look into the accident to help establish new procedural guidelines. Conroy told the News in July that the committee Yale established to examine shop safety has “done a great deal of work on all aspects of the shops,” including access and monitoring guidelines, safety equipment and training regulations.

Conroy estimated in July that the internal committee’s final recommendations would be published and officially implemented around the beginning of the school year.

Conroy said on Tuesday that, although they had not yet been released, some of these recommendations had begun to be implemented, including “increased awareness by users of safety rules,” and the presence of monitors in shops at all times when undergraduates are working.

“When something like this happens we want to be entirely confident that we have the right policies and procedures in place to protect our students,” University President Richard Levin said in an interview with the News on the day Dufault died.

Dufault was discovered around 2:30 a.m. on April 13 by two male undergraduates who called 911 and asked for immediate police assistance, according to a police report obtained by the News.

The official cause of Dufault’s death was “asphyxia due to neck compression,” according to Connecticut Office of the Chief Medical Examiner investigator Kathy Wilson.

Check back for more updates.