blue
business
chemical
chemistry
circle
compartment
construction
container
cylinder
diesel
distribution
energy
engineer
environment
equipment
factory
fence
flammable
fossil
fuel
gas
gasoline
generation
global
green
industry
large
liquid
manufacturing
metal
natural
oil
organization
pipe
pipeline
plant
pollution
power
refinery
security
sky
station
steel
storage
substance
tank
technology
toxic
warehouse
white