He walked into Saint Barnabas Hospital asking to be treated for a rash — but more than eight hours later, Jon Verrier was found dead in his chair in the crowded ER waiting room, hospital officials concede.

The 30-year-old amateur artist may have been dead for hours, according to a mortified employee who was there in the Bronx emergency room Monday morning when the corpse was ­finally discovered.

“He was found stiff, blue and cold,” the employee said, speaking to ABC News on condition of anonymity. “He died because [there’s] not enough staff to take care of the number of patients we see each day. We need more staff at Saint Barnabas.”

Officials at the 461-bed facility said Verrier checked into the ER at 10 p.m. Sunday and was found dead at 6:40 the next morning.

Upon his arrival, he was registered, triaged and told to wait to see a doctor, said Saint Barnabas spokesman Steve Clark, adding that Verrier was told to wait inside the ER itself but for some reason returned to the waiting room and took a seat.

Between 10 p.m. and 2 a.m., his name was called “two or three times” and he did not answer, Clark said.

At 2 a.m., a security guard made a pass through the waiting room to roust the many homeless people who try to sleep there.

“Nothing was awry — he was moving, he was alive” during that 2 a.m. check, Clark said.

Surveillance video from elsewhere in the hospital recorded Verrier alive and “moving” at 3:45 a.m., Clark said.

“Then after 6, when security did another pass, he was dead,” the hospital spokesman said.

“His name was called several times on several occasions, and he did not respond,” Clark added, stressing that an in-house review found “all guidelines were met.”

But clearly, nobody was really “checking” on Verrier as he died unattended and untreated in plain sight of hospital staff, the anonymous worker counters.

“He was not checked on,” the employee said. “Based on the number of people in the waiting room, it is impossible to check on each person physically.”

Patients who check into Saint Barnabas’ ER are usually in for a long haul — the average ER wait times at the hospital are twice the New York state and national averages, The Post has learned.

It takes patients at The Bronx hospital a glacial average of 306 minutes to be treated and released — compared to the average 155-minute wait statewide and the average 137-minute wait nationally, according to the Medicare statistics.

At Saint Barnabas, the more seriously injured are also in for long waits. It takes an average of 112 minutes to get pain medication for a broken bone, for instance, compared to the state ­average of 63 minutes and the national average of 59 minutes.

Patients confirm those galling stats. “We got here at 1 o’clock and they didn’t take him in till the next day, 7 a.m.,” Alfred Murias, 34, recounted Saturday of a recent visit for a seizure suffered by his father.

Amazingly, hospital officials insisted that other long ER waits are irrelevant in this case and suggest the dying man may have played a role in his own demise by not answering to his name.

Family members told ABC that Verrier, who has struggled with drug addiction but had been clean for months, was a victim of hospital negligence.