Question for believers in "Laissez faire"?

If there were no regulations, what makes you think that working conditions wouldn't deteriorate? And for example, factory workers would have to work 14 hours a day in dimly lit factories, full of chemicals, with no mask, and on a machine that could cut there arm off if they make one wrong move. Because competition insures the survival of the fittest, and cheapest to run company's...the formers OK, but what to stop the ladder, from achieving its ends at any cost?