Frequently found in house dust, soil, fruits, nuts, and seeds, rhizopus often grows in fruit and vegetable garbage, or in forgotten leftover food. Exposure to large numbers of rhizopus spores has reportedly caused respiratory complications. Rhizopus can be an allergen and opportunistic pathogen for immunocompromised individuals, especially those with diabetic ketoacidosis, malnutrition, severe burns, or in some cases, the common cold.

May cause mucorosis in immune compromised individuals. The sites of infection are the lung, nasal sinus passages, brain, eyes, and skin. Infection may have multiple sites. This mold produces mycotoxins, which can be inhaled and ingested. Occupies a biological niche similar to Mucor  allergen/toxin. The Zygomycetous fungus is reported to be allergenic/toxigen, as well. As with all toxigenic molds, this fungus can alter DNA and cause permanent neurological, psychological, pathological, and immunological damage.

Cases of mucormycosis from rhizopus infection. This so-called non invasive mold has disfigured many individuals, who had seemingly effective immune systems.