A lot of areas classified as 'kitchens' often have inappropriate or excessive provision.
Questions to ask -
Are cooking fats/oils used in pans, fryers or similar?
If NO, then a fire blanket is not required
If YES, then a BSEN 1865 Light Duty fire blanket will be required
Where the above was answered 'YES' are any of the appliances over 3 litres fat capacity or over 300mm diameter exposed fat surface?
If NO, then the BSEN 1865 Light Duty fire blanket will be sufficient
If YES, then in addition you will require a Wet Chemical Extinguisher with an F rating appropriate to the fryer capacity (or a Heavy Duty fire blanket, although in practice no one makes or sells these)
That deals with the specific risks in 'proper' kitchens, you then have the more general risks present in both real kitchens & tea rooms, break out areas, etc etc:
Does the area have any special ignition & fire class risks such as equipment electrically powered like microwaves, kettles, etc?
If NO, then the area needs no specific cover and comes under the general A rating of the floor which it is on (floor rating, 30m rule etc)
If YES, and suitable extinguishers are not already adjacent in a general fire point, then an electrically safe extinguisher is required, CO2 being the most appropriate for enclosed electrical appliances and also indoor areas (Powder is also suitable by rating but has disadvantages in not being as able to penetrate the appliance as CO2, also it causes secondary damage and can obscure vision in the area of discharge which could cause panic or difficulty in escape)
Far to many times the extinguisher companies, helped by consultants or H&S advisers that know no better, bung a fire blanket & 2 kilo DP in every area vaguely connected with food & drink despite there being no risk present for the equipment particularly the fire blanket.
Water & AFFF are only suited to general A protection, not kitchen cover, with the typical office or shop these should be supplemented with CO2 for electrical risk areas such as kitchens, distribution cupboards, PC's etc.
Powder is not illegal indoors, the BS only advises (very sensibly) against it's use for escape route cover & in areas where the public or vulnerable groups are present because of the discharge obscuring vision & being smoke like in appearance. Because you can get the same floor area of cover from a 2 kilo DP at around £25-40 as oppose to a 13A water/foam & 2 kilo CO2 at a combined cost of £65-120 there will always be people that opt for the cheaper option - after all why worry about secondary damage etc as 'we'll never have a fire'......