Diesel Exhaust Indoors

Diesel exhaust particulate is classified as a human carcinogen. It also carries carbon monoxide, nitrogen dioxide and fine soot that goes deep into the lungs and stays there.

Unlike carbon monoxide on its own, you can see and smell this one — which is useful, because the smell is a fair signal that the ventilation is losing.

Where it hurts

Anywhere the air does not move:

• parking structures, basements and loading docks, where trucks sit and idle
• tunnels, shafts and partly enclosed structures
• workshops and bays with a machine running inside
• buildings under construction before the openings are cut, with equipment working inside

The concentration is worst behind the machine, at low level, and in the corner furthest from the opening.

What it does

• Short term: stinging eyes, sore throat, cough, headache, nausea, and feeling lightheaded — much of that is the CO in it.
• Long term: lung cancer, and there is good evidence for bladder cancer. It also aggravates asthma and heart disease.
• Somebody who has been in it all week may be well past feeling anything unusual.

Controlling it

In the order that actually works:

• Do not run it inside. Electric, battery, propane or pneumatic equipment where it exists. Site the generator and the compressor outdoors and run the cord or the hose in.
• No unnecessary idling. Idling produces some of the dirtiest exhaust there is, and most idling is habit rather than need. A machine waiting is a machine off.
• Extract at the tailpipe. A hose onto the pipe and out of the building is the single most effective thing in a bay or a dock.
• Ventilate deliberately — mechanical ventilation with a measured air change, not a propped door. And put the extract where the exhaust is, which is usually low and at the back.
• Newer engines are dramatically cleaner. Tier 4 machines and equipment with a working diesel particulate filter produce a fraction of what an old machine does — worth knowing when hire equipment is being chosen.
• Maintain them. Visible black smoke means a machine that needs attention, and it is producing several times what it should.

Habits

• Park nose out, so exhaust is not blowing into the building when the machine starts.
• Stay out from behind an idling machine. People stand in the plume without noticing because they are watching the work.
• A CO monitor in an enclosed space where anything diesel is running — it is the fastest indicator that the ventilation has failed.
• Say something when the air goes bad. Watering eyes and a headache in a group is not a bug going round the crew.