What is the ruling regarding a husband praying alone at his workplace (a factory) during break times, without combining prayers, knowing that he cannot find another job and that he has a beard, in France where it is difficult to find work?

Your husband is permitted to pray at his workplace if that is the reality of the situation, provided he observes the prayer times. Congregational prayer (Salat al-Jama'ah) is obligatory for those who hear the call (adhan (definition)), but it is permissible to miss it for specific, legitimate excuses. We caution against the serious danger to one's faith and children that comes from residing in non-Muslim lands, especially those countries that prohibit the hijab (definition).