THERE are no winners when a shipper rejects a tank trailer due to inadequate cleaning. Contamination can ruin a cargo, resulting in lost business for shippers, tank truck carriers, and wash racks. All involved parties pay a price.
Bringing this blunt message to the tank cleaning community was David Raden, Eastman Chemical Company. He provided the shipper's perspective on tank cleaning during National Tank Truck Carriers' annual Tank Cleaning Seminar April 3 in Las Vegas, Nevada.
“When an Eastman product is placed in a tank trailer, that vehicle becomes our product package,” he said. “Product quality, upon delivery at the customer's facility, is a responsibility we do not take lightly. The carrier and the wash rack also share in that responsibility.”
Clean tanks are crucial to prevent product contamination. The cost of contamination can be high, because the Eastman chemicals are used in a wide range of products from automotive paints and coatings to pharmaceuticals. Factors include reimbursing the customer for the contaminated product and for all cleaning and disposal costs related to that shipment.
“We work very hard to prevent rejected shipments, and we are making progress through the use of root cause analysis,” Raden said. “We had 21 returns at our Kingsport (Tennessee) plant in 2004 resulting in 21 customer complaints caused by potentially contaminated tanks. By 2005, we had that down to nine returns resulting in five customer complaints.
“The tangible cost of each rejected shipment is estimated at $2,000, not including associated transportation costs. The cost of the complaint resolution and lost credibility and/or lost business with the customer can be much higher.”
That's why Eastman Chemical is adamant that the tank trailers used to haul its products must be clean, dry, odor free, and able to hold the cargo without leaking. It takes a commitment to quality to meet those requirements.
Even when a cargo tank is clean, it is not truly free of contaminants, according to Raden. Sophisticated analysis will show traces of the last three to five chemicals transported in a tank. Most of these trace chemicals are detected at levels of 25 to 100 parts per million (ppm), and that is usually not enough to cause problems. However, Eastman Chemical sells some products that are sensitive to contaminants at levels of less than 10 parts per billion.
Odors can linger in a freshly cleaned tank and generally are caused by chemistry. While some chemicals mix benignly, others react violently even when combined in very small amounts.
Raden pointed out that the water and caustics used in tank cleaning are chemicals. The salts and metals in the local water supply also are chemicals. All of them can cause reactions with other chemicals.
The reactions can show up as calcium or sodium salts that dissolve in water. However, Eastman Chemical's products are organic materials, and salts do not dissolve in them. Instead, the salts appear as white floaters or visible hard white specks. Just a few of these specks are enough to reject a shipment.
Eastman Chemical's ketone solvents are used to make clear automotive coatings that must be water white. Sodium acetate (used in airport runway deicer) at the 1-ppm level will turn the solvent yellow. The same thing happens with sodium hydroxide (cleaning caustic) at a 25-ppm level.
“That's why we audit the tank wash facilities used by our carriers,” Raden says. “We want to see how they clean tanks, and we want to be able to communicate with them if there is a problem. We do everything we can to ensure that our chemical shipments meet our customers' quality expectations.”