There was a great deal of consternation among many of the cast and crew when it came to light halfway through production that director Victor Salva had been convicted for child molestation several years earlier. The main cause of concern was that many of the production members had brought their family to the set.
Composers John Williams and Jerry Goldsmith both showed interest in scoring Powder. Williams demanded to see the cut first before he decides to do it. This was not possible due to the very tight schedule between finishing the film and releasing. So Goldsmith finally got the nod. Director Salva stated he is a big fan of Goldsmith's work, especially his film music from the 60's, but they both differed in what the film needed.
In a 2015 appearance on The Joe Rogan Experience comedian Barry Crimmins criticized the plot of the movie for implying that a child has power over an adult as representing a veiled or allegorical defense Victor Salvas history as a sex offender.
During the hospital scene where Ripley confronts the Sheriff about the classroom incident, we hear a voice on the intercom paging "Dr. Tarantini", "Dr. McGreal", "Dr. Cain" and "Dr. Grodnik". Tom Tarantini and Sean Cain are both actors in the film, Mimi N. McGreal is a production assistant, and Daniel Grodnik is the film's producer.
In 1997, two years after the release of the movie, British soprano Sarah Brightman recorded the song 'No One Like You' with the London Symphony Orchestra for her album 'Timeless' (for European market) 'Time To Say Goodbye' (for global market). Inspired by the character of Jeremy Reed, the lyrics were written by David Zippel on the main theme composed by Jerry Goldsmith.
In a scene that takes in a view of downtown Wheaton City in the movie, the Plaza Theater marquee indicates the movie playing inside is "The Nature of the Beast". That was a movie released in 1995 which also starred Lance Henriksen, who's Sheriff Doug Barnum in this movie.