I've made some research and for what it's worth, here's an overview of some mineral wool products that should be commonly available in most countries in Europe and to my knowledge can be used as OC substitutes.

**PAROC: COS 5**

Type: semi-rigid

AFR, Pa: **22 222**

WxL, mm: 600x1200 (alt. 600x1500)

Thickness, mm: 30-140 (100-180)

Density: 60-80 kg/m3

**PAROC: COS 10**

Type: rigid

AFR, Pa: **28 571**

WxL, mm: 600x1200

Thickness, mm: 30-180

Density: 100 kg/m3

PAROC: COS 15

Type: rigid

AFR, Pa: **66 667**

WxL, mm: 600x1200

Thickness, mm: 30, 50, 100, 120, 140, 160

Density: -

**PAROC: FPS 14**

Type: rigid

AFR, Pa: **20 000**

WxL, mm: 600x1200

Thickness, mm: 20-120

Density: -

**PAROC: UNS 37**

Type: flexible

AFR, Pa: **7 629**

WxL, mm: 565x1320 (alt. 870x920; 610x1170; 260x1320)

Thickness, mm: 30-200 (100 - 175; 50 - 175; 50)

Density: 26 kg/m3

**PAROC: UNS 35**

Type: flexible

AFR, Pa: **9 091**

WxL, mm: 565x1320 (alt. 870x920; 610x1170)

Thickness, mm: 30-175 (100 - 200; 50 - 175)

Density: -

**ROCKWOOL: Multirock 35**

Type: semi-rigid

AFR, Pa: **10 000**

WxL, mm: 1000x565 (alt. 1000x610)

Thickness, mm: 50, 75, 100, 120, 150, 200 (50, 75, 100, 120, 150, 200)

Density: 35 kg/m3

**ROCKWOOL: Rockton**

Type: semi-rigid

AFR, Pa: **16 667**

WxL, mm: 1000x600

Thickness, mm: 50, 80, 100, 120, 150

Density: 50 kg/m3

**ROCKWOOL: Fasrock**

Type: rigid

AFR, Pa: **33 333**

WxL, mm: 1000x500

Thickness, mm: 20, 30, 50, 70

Density: 135 kg/m3

** ROCKWOOL: Industrial Batts Black**

Type: rigid

AFR, Pa: **14 286**

WxL, mm: 600x1200

Thickness, mm: 15, 20, 30, 50

Density: 60 kg/m3

As you can see, some of the above are more similar to OC-703/705 some are less, but nevertheless I think all of them have use in some situations.

with kind regards.