Thirteen states have a funeral board or crematorium authority in charge, while another 10 rely on the state Department of Health for oversight. But in Kentucky, for instance, the attorney general's office is supposed to monitor crematories, while in Arizona the Real Estate Commission does the honors and in Louisiana the Environmental Quality Department is in charge.
Another factor making oversight tough is that crematoriums, by nature, tend to be tucked into out-of-the-way, hard-to-monitor locations, from industrial zones to rural areas.
"Crematoriums are like prisons," says Snyder. "You need them, but you don't want them in your neighborhood."
That's not the case in some other countries, though — especially in Britain, where cremation first became popular in the 1870s.
"If you look at the British traditions, crematories are on the grounds of cemeteries," notes Carlson. She argues that such an arrangement helps de-mystify the function of crematoriums and helps keep standards high by locating it more or less in public view.
But only one state, Texas, requires that kind of setup. Two other states, Massachusetts and New York, have the majority of their crematoriums on cemetery grounds as well.
Adding to the regulatory problems, it does not take an exorbitant amount of cash, by business standards, to join the industry: Most experts believe it takes between $50,000 and $100,000 to set up a crematorium.
For his part, Snyder says his group would welcome further regulation and has drafted a model of what it thinks the law should look like. In lieu of uniform laws, though, the CANA asks its 1,200 members to sign a Code of Cremation practice stipulating that bodies should be handled with "the greatest care," and offering guidelines on disposing with bodies quickly and cleanly, using a standard system of identification..
Given the current concerns people may have about crematoriums, though, Hankins recommends they ask funeral directors questions about the crematoriums they use. Some basic queries:
How long has the funeral director used the crematorium? How many days does it take to cremate the body? What form of identification does the crematorium use?
Morbid as it may seem, people can also ask to inspect crematories for cleanliness.
Hankins, however, thinks the case in Georgia — where Marsh remains in jail, pending charges — is so unusual that people will not think it represents the industry as a whole.
"This is the most bizarre kind of situation imaginable," he says. "I don't see this as a real [long-term] problem."
ABCNEWS.com's Peter Dizikes and Romy Ribitzky contributed to this report.