In the following matters, where the branch agreement or the agreement covering a wider territorial or professional field expressly so stipulates, the company agreement concluded subsequent to that agreement or agreement may not contain stipulations different from those applicable to it by virtue of that agreement or agreement, except where the company agreement provides guarantees which are at least equivalent:
1° Prevention of the effects of exposure to the occupational risk factors listed in article L. 4161-1;
2° The professional integration and maintenance in employment of disabled workers;
3° The number of employees above which union representatives may be appointed, their number and the development of their union career;
4° Premiums for dangerous or unhealthy work.
The equivalence of the guarantees mentioned in the first paragraph of this article is assessed for each set of guarantees relating to the same matter.