Man Dies After Using Cyanide in Garage : Van Nuys: Police call the death an accident or a suicide. The chemical was for the victim’s jewelry repair business.

A Van Nuys man died early Thursday after police responding to a domestic dispute found him unconscious near a container of heated potassium cyanide, authorities said.

Police said they were investigating the death of Rodolpho Tamaseo, 50, as an accident or suicide and did not believe foul play was a factor.

“I don’t think for a minute this is a homicide,” said Los Angeles Police Detective Joel Price. “It’s going to be either an accidental death or a suicide. It may be very difficult to determine.”

Tamaseo operated a jewelry repair business in his garage in the 6700 block of Jellico Avenue, where he was found before dawn Thursday, and kept supplies of potassium cyanide there for cleaning gold, said Michael Little, a spokesman for the Los Angeles Fire Department.

Little said it is legal to buy the substance in relatively small amounts for such home-based businesses, and that sodium cyanide or potassium cyanide are commonly used as jewelry cleaners.

But experts also said that granular potassium cyanide can become lethal if mixed with acid, improperly mixed with other liquid solutions or heated to such a degree that it becomes highly concentrated. Poisonous gas can be released in each of those instances, they said.

The worst possible combination, they said, would be cyanide and acid, which would produce hydrogen cyanide, the lethal gas used to kill millions in German concentration camps.

“You have to be very careful,” said Ricardo Silva, chairman of the Cal State Northridge chemistry department. “The cyanide vats have to be properly ventilated and workers have to be protected.”

A liquid form of the substance was simmering on some sort of heating device--police and fire accounts differed on whether it was a hot plate or Crock-Pot that was being used--when officers found Tamaseo. Little said police turned the device off and most of the fumes had dissipated by the time a Fire Department hazardous materials team arrived.

The team confirmed that the substance was potassium cyanide but determined that the fumes posed no threat to neighbors, Little said. Four firefighters and two police officers were taken to Northridge Hospital Medical Center for observation and soon released, he said.

Tamaseo’s 14-year-old son, whose name was not released, was also taken to the hospital for observation. Police found the youth trying to revive his father with cardiopulmonary resuscitation.

Price said detectives were investigating the possibility of suicide because of a report that Tamaseo talked about taking his own life during an argument with his wife. Officers were summoned to the family’s house after Tamaseo struck his wife, Price said.