Demetechnics was a small corporation that was the organization behind the Eternal Youth Spa and a minor antagonistic group in the episode "Eternal Youth" Batman: The Animated Series.
Poison Ivy set up Demetechnics—named after her alias Daphne Demeter—to legally run the Eternal Youth Spa and produce her toxin called Demetrite.
The Eternal Youth Spa
The Eternal Youth Spa is supposedly a health resort that was rumored to have a chemical that will give people youthful contents. But actually it was a ploy used by Poison Ivy aided by both her 2 loyal assistants Lily and Violet to exact her fanatic revenge on many wealthy men and women she blamed for ruining some of the Earth's rainforests.
By offering them a free treatment at the spa—boasting a new method using Demetrite — she slowly poisoned the guests until they turned to trees.
Batman stopped her and escaped the Eternal Youth Spa which was destroyed by a giant tree that was the result Poison Ivy's Demetrite.