Green Slime, came out when trying to pump tyres

Hello folks,
I had green slime added to my tyres recently, by Halfords. When I tried to add air to the the tyre, a gush of green slime sprayed over me. Is this normal? Does green slime not require you to inflate tyres? I'm just wondering if I have lost the pressure and I dont want my bike pump to get broken by the green slime?