According to cnn.com, "…nearly 2.2 million adults were held in America's prisons and jails at the end of 2016," of which a portion of those so locked up are subject to being coerced or compelled into providing labor services either directly within that prison or jail, or to be outsourced to certain companies or government agencies so as to perform uncompensated or extremely low paying compensated jobs. To a certain extent, those incarcerated, with little or nothing to do of substance, are amendable to performing such work duties, but to do so, for no pay or extremely low pay as well as having to deal with possibly hazardous working conditions, should be seen for what it is, outright exploitation of labor for the benefit of those so employing these incarcerated people.
While critics might so indicate, that prisoners should not be compensated at the prevailing labor rate as well as they should not be subject to the rules and regulations that Federal and State laws so dictate, because these people owe a debt to society for having been duly convicted, this presupposes that the very nature of being incarcerated means that certain laws in regards to worker safety, compensation, and work conditions, somehow do not apply to those that are in a current status of being incarcerated. If this be so, then it would mean that for any municipality or its equivalency, that when labor is short or budgets are tight, such as, for example, in harvesting season, that it would be pro-active and well-nigh prudent for the policing forces of that municipality to arrest and to convict as many people as is possible, for dubious crimes such as vagrancy or criminal mischief, so as to build up a convict labor force that could thereby be exploited as cheap and ready labor.
The thing about incarcerated laborers as opposed to all those that are not compelled or coerced into working, is that incarcerated laborers are prone to being overworked and to suffer to a degree that others would not readily tolerate, because those others have the willful capacity to walk away, whereas incarcerated laborers do not. Further, the overall health of an incarcerated laborer and even the long term endurance of an incarcerated laborer are of little concern to the employer of such, because these convicts represent something that is merely seen as temporary help, and thereby of no compelling concern to those "employing" them. This so means that incarcerated laborers, in which appropriate labor and workplace rules and regulations do not apply, or are not effectively applied for them, are not only susceptible to being exploited -- but are exploited by those so employing them, because the ramifications of something going wrong or of being adjudged not appropriate, whatever it may be, is often negligible, whereas the upside of the usage of free or nearly free labor is quite good.
Those that are incarcerated have it bad enough already that they should not thereby be seen as a labor resource to be exploited, nor should they be placed within working conditions that circumvent a safe and appropriate working environment. To the extent that the government or private enterprise wishes to employ incarcerated laborers, such should be an option, but only should be done in good compliance with the Fair Labor Standards Act as well as other applicable legislation.