Here’s an urban legend that is very common but to my knowledge has not been addressed here or on snopes:
Foodstuffs such as milk and vegetable oil and corn syrup are transported in the same tankers as petroleum and pesticides, often without even washing out the tanks.
Lots of the folks around here swear it’s true, but I can’t see it. Milk with benzene? They all think so… :rolleyes:
Milk trucks carry only milk, and use stainless steal tanks. Milk was carried to the dairy in milk cans made of iron before the tanker trucks came about. The milk cans were often kept cool in a spring house. They went to market in glass bottles. then paper cartons and now plastic jugs. Why anybody would believe companies are allowed to put milk in a tanker that has been hauling around dangerous chemicals is beyond comprehension? Besides milk, all they put in them is water and cleaning agents to sterilize them.
No cite, but I’m as sure as I can be that that is false. For one thing, the tank liners, piping and fittings have to be made of materials that are compatible with the cargo being carried. I doubt that exactly the same materials could be used to safely contain both milk and pesticide. For that matter, the tanker could not generally be used interchangeably to haul, say, petrochemicals and corrosives.
I’m fairly certain that this UL came about because someone unfamiliar with the technology sees tankers that look superficially similar from the outside, and thinks any tanker can carry any material.
Potentially hazardous chemicals have something called a UN number, and tankers carrying them must, by DOT regulation, carry placards (those diamond-shaped graphics) displaying the UN number and a symbol indicating the hazard type. For example, UN 1203 is gasoline. I don’t think you’ll find a UN number for milk, and likewise, you are unlikely to even find the fittings for placards on a milk tanker, because the substance is not considered hazardous.
I bet a lot of the nasties are less corrosive than milk. Milk is a slightly acidic aqueous mixture, whereas benzene is just a rather boring organic solvent.
As for labels on the trucks, I recall a tanker truck parked on NMSU’s campus many years ago. The little diamond warning label (not the UN number) could be flipped to a bunch of different hazards, so it seemed that they could put different stuff in the tanker. Probably not milk though.
It is not legal, but that is not to say it hasn’t been done.
My father worked for a large Chemical trucking company most of his life and he told me about a company that had been fined for hauling diesel fuel in one direction and milk in the other in the same tanker.
Of course, that was at least 20 years ago and Dad has passed, so I can’t give you a cite.
After many years in the petroleum industry, I note I NEVER saw a tanker of stainless steel,they are invariably aluminium, but more importantly are outfitted with safety equipment to prevent static spark, interface with terminal metering, recoup volatile vapour, and have requisite compartments and inlet/outlet to enable delivering the (up to) five typical products to petrol stations using “drybreak” connections.
In farmland all the tankers that pick up from dairies are exclusively stainless and though built to the same TTMA standards use different appurtenance. I’m sure they have bulkheads to provide strength and prevent sloshing but there appears to be only one access hatch.
Just a guess but there are likely no “general haulers” in liquid transport.
There’s what is legal and then there is real life.
Milk isn’t supposed to be carried in tank trucks that had carried nasty stuff, but once in a while a trucker is found doing just that. There was a bunch of such incidents reported in NY and PA a few years back.
One can assume that for each one caught there’s thousands that go by undetected.
We’ve had it drilled into our heads in both hazmat and driving classes that milk tankers are the only tank vehicles on the road without baffles in the tanks - the tank has to be cleaned after each load, and the baffles overcomplicate that cleaning process (too many nooks and crannies to clean).
We’ve also been taught that milk tankers are either all the way loaded or completely empty, because the sloshing of the milk in a partially full tank (without the baffles to restrain it) can roll the truck.
Of course, I’ve learned not to trust everything I’ve been taught, so YMMV.
You know what happens when you assume, right?
If milk was frequently carried in the same trucks as hazardous chemicals, there would be a lot more people getting sick from eating milk and dairy products.
It makes sense that this would be the ideal situation, but it’s not possible to do this at all times. There are lots of small suppliers who don’t produce enough milk to fill the tank. Routes are hopefully optimized to minimize the distance traveled with a partially full tank.
You would also make butter from the sloshing in the tank.
The trucks always had a set route they drove, and they went from farm to farm until they needed to empty the tank back at the dairy plant.
I did run across an article about a new seven axle milk truck. It was designed so they could legally collect milk in Wisconsin from the new large farms. Apparently we have a regulation requiring all the milk from a milk tank on the farm to be hauled in one load to the dairy and what doesn’t fit in one load must be dumped. I suppose this is to ensure the farm refrigerated tanks are emptied and cleaned.
No cites yet, but the anecdotes…:eek: I’m thinking about extracting all my milk into ether and shooting it on the GC/MS before drinking it.
Not to mention that routine sampling at the milk processing facility would pick up said contamination during testing. Milk gets tested for lots of things, and I doubt that a dodgy trucker moonlighting for the pesticide company would get away with contaminating a vat of milk. In fact, I recall that dairy processors test each individual tanker load, to prevent too much milk having to being discarded when contamination is detected (antibiotics, hormones, toxins and pesticides), and to provide tracking to identify farms with a problem. Of course, this was in NZ where we take our totally natural dairy produce very seriously. But it terms of regulatory framework, I doubt that anywhere else is much different.
It may happen very occasionally, but no-one will get away with it for long.
Si
In CT, you need a permit for any “bulk milk pickup tanker”, and they do annual inspections.
It sounds like they are more considered about drug residue build-up.
Got to love urban legends or even oh no! my baby Johnnie has been poisoned by the evil corporations.
Can you imagine the outcry if this was found out to be true? Almost all food except for vegetables would be under scrutiny. Talk about corporations shooting them selves in the foot.
I understand you are just reporting what you hear locally, and that does deserve a huge rolleyes.
Even though I think the FDA should be expanded somewhat, I can safely say that this is complete BS.
My dad used to haul milk. I can tell you that, for his company at least, there is no way this is true. His tankers had to be sterilized after every load of milk was emptied so they never put milk into an unsterilzed tank. His company only hauled milk, so I can’t say for sure that cross loading doesn’t happen, but I can tell you that not washing out the tanks between loads does not happen.
Also a couple of fun stories about partial loads of milk. If you are starting off up a hill with a half load of milk, there was a neccesary technique to use. You would have to let the clutch out and pull forward a few feet, then push the clutch back in. Then after the right amount of time (a second or two) you would let the clutch out again and take off.
This was timed so the intial forward motion would get the milk running to the back of the tank. The idea was to time the second motion forward so that the wave of milk had already bounced off the back wall of the tank and was moving forward. If you didn’t do it right, you would kill the truck when all the milk piled up against the back of the tank.
Another time, my dad had pulled into a building to finish loading a half tank of milk. He had already opened the hatch on top, but was not far enough forward to fill the tank. He thought that if he were careful, he could move the truck forward a couple of inches without need to close the hatch. He said that milk hit the ceiling - which was about 30’ high.
Many of these urban legends can be exposed with just a bit of common sense, economically. Ask How would they make more profits doing this?
Milk trucks are more expensive than oil tankers! They are stainless steel, vs. cheaper aluminum for tankers. Milk trucks have no internal baffles, the unloading pipes are different so they wouldn’t connect to an oil terminal. Milk trucks don’t have the grounding strap that oil tankers do; no sensible driver is going to stand next to a truckload of highly flammable liquid that is ungrounded.
Plus all the obvious issues with contamination – in both directions! The oil would contaminate the milk, but the milk would also mess up the oil. Raw milk contains a fair amount of sugar; you’ve heard of the results of putting sugar in a gas tank? Just like dairies, oil terminals test loads when they are delivered.
It just would not make economic sense to do this.
In the interests of fighting ignorance, I believe this is an UL. Sugar isn’t soluble in Petrol.
tim
Yes, that’s why it is so damaging!
If it was soluble it would just dissolve into the gas (petrol), and be burned up. Instead it stays as sugar, and clogs up the fuel filter, and fuel pump, and carburetor or fuel injectors, if it gets that far. And it stays as a sticky, sugary mess that is very hard to clean off those expensive parts – often they just have to be replaced.
This was covered in the Straight Dope already:
http://www.straightdope.com/mailbag/msugargs.html