Connie, I will be sterilizing at home before bringing to office. but I will only be expressing at most one time in office cos I will o nly be working from 2pm to 530pm. Leave home about 115pm, reach home about 615pm. Have to see how bb's feeding schedule is, cos I was told try to feed on demand and express when bb is feeding throughout the day so that our bodies know how to produce milk supply, esp when I'm aiming for oversupply. But chances are by 4 months, the bb will be feeding once every 3 hours (at most) cos express at home at 1230pm, express in office at 330pm,then express again at home at 630pm, so I will only need to express once in office. no need to sterilize unless I drop something or contaminate it, then need to emergency sterilize in office.