background
barrel
black
blue
chemical
chemistry
colorful
container
crude
danger
dirty
drum
dump
ecology
empty
energy
environment
factory
fuel
gallon
garbage
gas
gas station
grunge
hazard
hazardous
industrial
industry
metal
oil
old
petroleum
pile
pollution
position
recycled
recycling
rubbish
rust
rusty
safety
stack
stacked
steel
storage
tank
toxic
used
waste
white