I have got a Osram St111 with the Datucode Emf. How old is this fluorescent starter?

Not sure about that. What is the case style tho ? Printing on the side or on the top ? If on the top, embossed and painted Black or just embossed ?

Look heer
https://static.wixstatic.com/media/6e01f1_8bc3d8af04e74482995a67f61f9a0855~mv2_d_5152_3864_s_4_2.jpg/v1/fill/w_600,h_450,al_c,q_80,usm_0.66_1.00_0.01/6e01f1_8bc3d8af04e74482995a67f61f9a0855~mv2_d_5152_3864_s_4_2.jpg
https://static.wixstatic.com/media/6e01f1_bb07868190424ad9b1fad3dc28ec2437~mv2_d_5152_3864_s_4_2.jpg/v1/fill/w_600,h_450,al_c,q_80,usm_0.66_1.00_0.01/6e01f1_bb07868190424ad9b1fad3dc28ec2437~mv2_d_5152_3864_s_4_2.jpg
The 2 left

The 3 are 80s maybe at most 1990 or so. (i dont know whether back in the days of West Germany Osram printed Germany or West Germany). The one with the top print is between early and late 90s. In the late 90s they changed to more or less today's print style without the paint

The two first would actually be the same age that is from the 80s . 1983 PCB in the EU bans and thus the metal starter . The 3 takes about mitt 90s be because he was in a light that my father bought for 2000th The ltzte takes etas younger sien , Ca in 2008, he was in a much used  classroom my school .

What it have to do with PCBs (not the Printed Circuit Board) ? Starters never contained them

The new light your dad bought could have been a decade in storage before that, especially if it was a last one on a high shelf. I'd expect that the starters used in school were put to use shortly after anufacture, due to the quantities bought by users like schools and their suppliers, where things dont stay in storage for long

The German and Dutch metal Starter contained PCB resin. In the Mazda S1 metal also PCB resin was because they were built at Philips.

In the paper isolator ?

no idea.
It was write at the website from Magslight

The Staters are from 1980

In the paper isolator ?

The insulating paper of the capacitor was impregnated with wax that contained PCBs. But all starters made after 1969 were safe according some tests of a state owned lab in Switzerland.
Also Philips and Osram seems to changed the from metal to plastic housing in the same time era. I have some very early 1970's starters that already have plastic housing.

look hier, im look to the Datumcode Emf
http://www.lighting-gallery.net/gallery/displayimage.php?album=1990&pos=5&pid=77369

I thought it would be the paper that is in the metal case, if it was the reason for moving to Plastic cases