During a May raid on her home in El Cajon, east of San Diego, federal agents seized kits that sold for $40 each and essentially consisted of a plastic bag and clear tubing.
Hydorn said she sold the kits under the name "GLADD Group." Court documents say she sold more than 1,300 kits to people across the United States and abroad. Most of them contacted her by mail or phone.
Hydorn, a retired school teacher, told authorities she knew the kits were intended to be used to commit suicide but she said she thought they would be used by the terminally ill.
Prosecutors, however, said she took no steps to verify the physical condition, age, identity or mental state of her customers and therefore had no idea whether her kits were being bought by people suffering from depression or by minors acting without the consent of an adult.
Prosecutors said Hydorn also tried to hide the true purpose of her kits on U.S. Customs forms by listing them as an "orchid humidifier," or "beauty bonnet" and "plastic rain hood."
After the raid on her home, Hydorn told The Associated Press that she wasn't responsible for who uses the kit and was only trying to help people in pain. She said she had been in business for three years and sold up to 60 kits a month.
According to court documents, Hydorn's helium hood kits consisted of medical-grade tubing, a plastic bag with an elastic collar, or "hood," and a diagram on how to use the kit. The kits caused death by helium asphyxiation once the hood was attached to a helium gas source - which was not part of the kits.