Dry-cleaning upholstery and carpeting-- anything hazardous in there?

[Black Landlord]

New business across the alley-- guy pulls his "Chem-clean" van across the garage entranceway and spends the day cleaning whatever it is his clients give him.
The noise is not too horrible, but I'm wondering if there are any sort of chemicals I should be worried about. Anyone familiar with the process? It's about 15 feet from my patio/container garden.
Thanks.