Will these microbes harm wetlands, asphalt, grass, dirt, rubber, plastic, or metals?

No. The Bacillus spores, in all likelihood, are already present in the soils and waterways of the earth’s wetlands. The spores are very tolerant of brackish and sea water. The microbes do not recognize roadway asphalt as a food source. Micro-Blaze® Microbial Products are used by golf courses and farms to improve the health of the grass. These Microbes only digest organic materials and are therefore safe on all rubber, plastic, and metals.