Real Stories of the Highway Patrol 60: Megaseal MSDS

This is the Material Safety Data Sheet (MSDS) for Meggison Enterprises, Inc. crack filler and sealer that CDOT uses.
Note that it is "A hot applied asphalt based crack filler and sealer".
And also note;

"When asphaltic products are heated, they often give off small amounts of hydrogen sulfide. Hydrogen sulfide is an extremely flammable, toxic gas. BREATHING HYDROGEN SULFIDE MUST BE AVOIDED".
So the real concern is the MSDS for Hydrogen Sulfide . If you are using this stuff, be sure to check it out!!

For those of you who do not use this stuff, Here is a little background on how CDOT uses Megaseal. The product is a solid asphalt product. The product is packaged inside a plastic bag that is inside a cardboard box. The cardboard box allows the product to be stored, shipped, and used in temperatures above it's starting melting point of 77 degrees.
This stuff is heated to 375 - 400 degrees in a "tarpot". The tarpot is a trailer that has a large tank (pot) that you put the Megaseal blocks (stripped of the cardboard and plastic) into. A burner (diesel) heats a special oil that is pumped through coils inside the tarpot, which in turn melts the Megaseal blocks. I think the tarpot holds about 250 gallons.
When operating temperature is reached, the product is liquid and so hot that it is smoking. Then it is poured with a mechanical pump/wand into cracks in the pavement. Every few minutes someone opens the door on the top of the tarpot and adds a few blocks of Megaseal to replace what has been used. One or two workers will follow the person pouring the cracks with small squeegees and remove excess product. The whole crack pouring operation requires 7 to 8 workers. Two trucks - one pulling an air compressor and the other pulling the tarpot, with two drivers, and one person to blow sand out of the cracks, one person to pour cracks, one to two people on squeegees, and a couple of flagmen. Everybody rotates about every 15 minutes so that everyone shares the fun. The purpose is to seal cracks in the road and keep moisture out.
This whole process is called as "crack pouring", or better known as "pouring money on the road". It probably helps a little bit in keeping moisture out, although after a month or so the "sealed" cracks will begin cracking out again in some places.

You can't apply this product without breathing the fumes, which contain hydrogen sulfide. It contaminates skin, eyes, clothes and lungs. It makes you cough. It makes my chest hurt for several hours each night after being around it. At about the second or third week of pouring cracks I get slight cough and slightly wheezy breath. It seems like the start of a cold, but it is actually the symptoms of exposure to lower concentrations of hydrogen sulfide.
A gas mask would probably filter out the fumes, but they are difficult to breathe through under normal conditions, let alone during physical activity such as crack pouring. The MSDS says you need a NIOSH approved respirator in confined spaces. The tarpot is a confined space. When someone opens the hatch they usually get a good dose of smoke. This smoke drifts with the breeze. As everybody rotates positions, there is no "downwind" position where you can work. Maybe someday CDOT will get a substitute product that is not hazardous to our health. In the meantime, if you are using this stuff be careful!
However, CDOT provides Maintenance employees an unlimited supply of the cheapest paper dust masks on the market.

Below is a photo of the Evil Dragon.

Real Stories of CDOT Highway Patrol 60

Megaseal MSDS

Below is a photo of the Evil Dragon.

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