As CT says, not needed. No legal requirement, no risk (or there shouldn't be), no trained users, risk of theft and vandalism. If the occupiers want to buy themselves one from B&Q that's up to them.
The only people who say you need them are often those who are also selling them, or people who don't really know what they are on about.
In the years I've been doing this job extinguishers are starting to appear to stupid levels in the wrong places, in too many numbers and inappropriate types and I'm actually requiring more to be ripped out than put in these days. My clients need to target their money at training, passive FP and fire detection and warning not loads of extinguishers that serve no purpose than making someone money.
And I am very pro extinguishers usually, but it's getting beyond a joke now, too many suppliers doing 'risk assessments' to try and sell as many extinguishers, blankets and glow in the dark signs as they can (& still they get it wrong, I've seen firms happily put water & CO2 extinguishers on plain concrete unfurnished, undecorated, unused except to evacuate, fire stairs, yet try and cover a 45 litre cooking oil fryer with a blanket and ABC Powder extinguisher!)
