Is it alright for an exhaust fan to vent into the loft?
Bad, bad, bad.

Mold will be in evidence shortly in the loft (attic), as we go into warmer weather.

The vent must run to the exterior, either through a gable wall or through the roof.  Its easier to properly down-slope to the gable wall (to eliminate any condensation in the vent pipe.

To reduce pipe condensation (either inside or outside of pipe), a jacket of insulation is suggested.  Also suggested is smooth walled pipe, gradual turns and no screw penetrations into the vent airspace.