Virginia Tech water expert Marc Edwards charged Tuesday that a water nonprofit supported by actor Mark Ruffalo, who played the Hulk in the last two Avengers movies, created a “false alarm” that potentially jeopardized the health of Flint, Mich., residents.

“I spoke to this group and I said ‘do you realize if you scare people from taking baths, or showers, or washing their hands … people will get sick,'” said Edwards at a Tuesday press conference. He was joined by several scientists who presented their research showing that Flint water meets federal standards, contradicting claims by Ruffalo’s group, Water Defense.