Harvard Hillel’s Rosovsky Hall will reopen today for the first time since last Thursday after powder found in an envelope at the building tested negative for anthrax.

In an e-mail sent to the Hillel community before 4 p.m. yesterday, Hillel officials announced that the white powder a Hillel employee discovered last week contained no contaminants and “is probably a form of packing material.”

The envelope was sent to the State Laboratory in Jamaica Plain for testing last Thursday, but Hillel did not receive word of the results until yesterday.

A spokesperson for the University said she had not yet received any specific information regarding the Hillel envelope, but an updated safety message on the University website read that no suspicious mail within the Harvard community has yet tested positive for anthrax.

Hillel activities were not substantially affected by the closing of the building, according to Benjamin Z. Galper ’02, chair of Hillel’s Coordinating Council.

“We worked with the University to get rooms for four different Shabbat services,” Galper said.

He said the University provided Hillel with temporary space in the Yenching Library, in Winthrop House, in Loker Commons and in Memorial Hall.

“We also ate in Adams dining hall on Friday night and we only had to postpone one event [overall],” Galper said.

Galper said that although members of the Hillel community were concerned until the State Laboratory finished its tests, many suspected the powder found in the envelope was harm