There isn't. We say 'firefighter' for both men and women. English is a much less gender-specific language than Spanish, for example. As you know, we have many words - cousin, neighbour, friend, teacher, student, for example - which are used for both men and women. In the field of employment, it is becoming less and less usual (and less and less politically correct) to use gender-specific job titles. For example, we rarely use the term 'air hostess' any more, and prefer the neutral term 'flight attendant' instead. As for businessman and businesswoman, these terms may well fall out of use soon in favour of the more neutral 'businessperson.'