WASHINGTON — A federal inspection of a company whose tainted pain medicine has caused one of the worst public health drug disasters since the 1930s found greenish-yellow residue on sterilization equipment, surfaces coated with levels of mold and bacteria that exceeded the company’s own environmental limits, and an air-conditioner that was shut off nightly despite the importance of controlling temperature and humidity.

The findings, made public on Friday by the Food and Drug Administration, followed a report from Massachusetts regulators on Tuesday and offered disturbing new details in an emerging portrait of what went wrong inside the New England Compounding Center, the pharmacy at the heart of a national meningitis outbreak in which 25 people have died, 313 more have fallen ill and as many as 14,000 people are believed to have been exposed.

Instead of producing tailor-made drugs for individual patients, as the law allowed, the company turned into a major drug maker that supplied some of the most prestigious hospitals in the country, including ones affiliated with Harvard, Yale and the Mayo Clinic, all with minimal oversight from federal regulators.

Federal officials also drew attention to the company’s proximity to a recycling plant where excavators and freight trucks heaped old mattresses, plastics and other materials, generating large amounts of dust. The plant, which is owned by one of the same people as the pharmacy, has not always complied with regulations and has drawn complaints, according to records in Framingham, Mass., where the company is located.