Microbial Growth During Handling, Packaging, Shipping and Storing Contents

Packers, shippers and movers can protect themselves from visibly microbial contaminated goods.

• By Bernard Fontaine
• Nov 16, 2022

People are constantly moving locally, across the country, and abroad for a better life or job opportunity. The moving industry is considered to include “local and long-distance transportation of household and office goods as well as storage, warehousing, packing, packaging, processing, distribution, and other related services.

According to the American Moving and Storage Association (AMSA) in February 2019, revenues topped $12.6 billion in annual sales. Long and local distance moving accounted for 69.6 percent of revenue while 20.2 percent were for storage and warehousing. Nearly 44 percent of the population were individuals, 30 percent were corporations and 16 percent were from the federal government. Shipping was done by primarily local movers (61.4 percent), intrastate (20.1 percent), interstate (15 percent), and international (3.6 percent). The AMSA’s study on interstate moves showed that about 21.7 percent of the people moving hired a mover for long hauls across the country. This information was based largely on a recent study of three million interstate moves, where 650,000 people hired a mover whereas one million people rented a truck and 1.35 million people moved “un-assisted.”

So it’s time to select a moving company to move the commercial or home office and household goods to the new location. This was the case involving a family who moved their belongings across the country. The selected mover packed all of their belongings inside wooden crates and stored them in an uncontrolled climate warehouse for about six months until they could find a permanent residence.

When the stored contents finally arrived at the new location, the property owners discovered some of the soft goods, paintings, furniture and painted objects were moldy. The movers and shippers were unaware of the microbial contamination inside the warehouse, long haul trucks and interior of storage crates. Well how could this have happened when they were in perfect condition when the movers packed and shipped the contents across the country? While our investigation was limited to the warehouse and the wooden storage crates on the east coast, we did not evaluate any of the stored materials or the ambient environment at the time of the move or during storage.

Microbes are present indoors and outdoors all year round in soil, water, air and on settled dust, inside and outside our body along with animals and plants. Molds, in particular, are very common in commercial buildings and homes. Mold will grow in places with a lot of moisture caused by leaky roofs, windows or pipes, or where there has been storm damage or flooding. Mold grows well on paper products, cardboard, ceiling tiles and wood products. Mold also can grow on dusty surfaces, paints, wallpaper, insulation, drywall, carpet, natural fabrics and upholstery. The most common indoor molds are Cladosporium, Penicillium, and Aspergillus. Information on sources of microbial growth can be found in the WHO Guidelines for Indoor Air Quality: Dampness and Mould, 2009.

There is no precise information about how often different molds are found in buildings, but it much depends on the substrate as a nutrient source, pH, temperature and/or environmental conditions, exposure duration and water activity, which contributes to surface dampness or moisture in the air. If the environmental conditions, substrate and nutrient sources are optimal, microbial growth may begin within 48 hours. Another point of interest are the cities within the U.S. with highest percentages of allergy and asthma patients that showed hypersensitization to microbes. According to the McLekule blog, the top ten cities for microbial allergy symptoms include: San Antonio, Kansas City, Denver, St. Louis, Minneapolis–St. Paul, Chicago. Los Angles, Phoenix, Riverside-San Bernardino and Dallas.

In the February 2018 issue of “The Dispatch,” moving companies were given a risk management bulletin to describe some of the concerns. In particular, valuable information was presented on mold prevention and what loss situations microbial damage was covered under the customers’ policy. To prevent mold from affecting clients’ property, one suggestion was to limit the amount of moisture during shipping or storage. The recommendation was not to pack, load or unload in high humidity situations. Movers should avoid packing and/or storing wet upholstery while loading and unloading or damp cardboard boxes. Storing, packing or transporting any liquids in unsealed containers that make leak or break, and therefore should not be packaged or handled by movers.

But what about the ambient environmental climate conditions in the storage units, crated objects, warehouse and trailer of a long-haul moving truck? What types of controls can be used to prevent microbial growth inside of the reusable wooden crates used to ship and store the contents? Do they remove dirt and leaf litter from inside the storage crates, warehouse or truck trailers? These were only a few obvious concerns that were raised during our microbial investigation. While some homeowners and commercial movers select storage cube rentals, similar exposures may exit.

The wooden storage crate where the contents were stored showed evidence of visible microbial growth. A single bulk sample, which was collected from the wooden crate and cultured on agar media, showed an elevated level of colony forming units (cfus) of Aspergillus species (1,000 cfus), Chaetomium species (7,000 cfus), Penicillium species (26,000 cfus), Stachybotrys species (1,000 cfus) and yeast species (5,000 cfus). While the preliminary evidence was inconclusive relative to the timing of the relocation and storage duration, the evidence showed that this wooden storage crate had active microbial growth. At the time of the investigation, the storage crate was being reused to store other belongings without considering the potential for cross-contamination of the newly stored items or direct skin contact exposure to the movers and warehouse workers.

Well, why is all of this important? Most Aspergillus species require free water for growth. There are some species of Aspergillus that can absorb water molecules directly from humid air. These xerophilic species of Aspergillus can grow when the relative humidity (RH) in the air exceeds 60 percent. This level of RH is commonly exceeded in the basements of many unconditioned building and homes without ventilation and dehumidifiers. It also can be an important factor during the summer months. In these cases, Aspergillus can become an airborne allergenic or asthmatic hazard if the fungal spores are disturbed from their substrate.

Special attention should be given to some species of Aspergillus like A. niger. A. niger is more likely to be pathogenic in humans than other species of Aspergillus. It is frequently isolated from ear infections and deserves some respect, as it is repeatedly associated with localized and disseminated infections in humans. Inhalation of airborne spores in high concentrations over extended periods of time can lead to diseases like allergic asthma, hypersensitivity pneumonitis, invasive aspergillosis, aspergilloma (fungus ball) and allergic bronchopulmonary aspergillosis. Certain species of Aspergillus can produce aflatoxin, a fungal mycotoxin. According to the World Health Organization, the mycotoxin can cause hepatocarcinoma (liver cancer) in humans.

Penicillium species are a ubiquitous genus of fungi with its many species recorded from the equator to the polar regions. Penicillium sps. are considered cold temperature molds. Because of this limitation, they are not considered as important clinical pathogens in humans. However, there are exceptions to every rule. Some strains of Penicillium sps. are considered rare opportunistic pathogens in humans, causing infections of the eyes, ears, lung, urinary tract and membrane lining of the heart (endocarditis). Most species are saprophytes in soils, decaying vegetation, seeds, wood, food and food products.

Chaetomium is another large genus with over 80 species isolated worldwide. These spores like fairly wet conditions to grow. Thus, Chaetomium sps. are often found growing on water-soaked wood, especially laminated forms, such as plywood, resulting in soft rot. Most Chaetomium sps. are saprophytes and are frequently recovered from soil, rotting plants and any other sources where there is an abundance of cellulose and water. Chaetomium sps. are not generally regarded as common agents of human disease. Several species have been implicated in mycotic infections of the nails, skin and brain and as agents of peritonitis (inflammation of tissue in the abdomen).

Species of Stachybotrys are distributed worldwide. Most fungal species are strongly cellulolytic, which are commonly found on damp surfaces where cellulose is available. Thus, they are commonly found in soil and on dead plant material. Stachybotrys is also detected in leaf litter, moldy hay and the nests, feathers and feces of free-living birds. They have been isolated frequently from the roots of many plants. Certain species of Stachybotrys (e.g., S. chartarum) produce a variety of mycotoxins, which may be responsible for symptoms ranging from Chronic Fatigue Syndrome to pulmonary hemorrhage in infants. Special precautions should be taken when removing building materials or artifacts, which are contaminated with this organism.

For many years, it has been known that certain types of mold exposures can make people sick. The 14^th chapter of the book of Leviticus in the Bible records how communities successfully handled indoor mold problems over 3,000 years ago. Exposure to damp and moldy environments may cause a variety of health effects or none at all depending on individual immunology. Of the 21.8 million people reported to have asthma in the U.S., approximately 4.6 million cases were attributable to dampness and microbial exposure according to the U.S. EPA and Berkeley National Laboratory, 2007. Other sources note that at least 45 million single and combined use buildings in the U.S. may have unhealthy levels of microbial growth.

Some people are sensitive to microbes in air. For these workers, some common symptoms of exposure include nasal congestion, sinus infections, wheezing, fever, headaches, "smokers" cough, chills, weight loss and red or itchy eyes or skin. Workers with allergies or asthma may have more intense reactions, especially for workers who may immunologically compromised by disease or medication or suffer from a cardiovascular ailment. Other workers may experience long-term effects including chronic fatigue, coughing or sneezing, irritation to eyes and mucus membranes of the nose and throat, persistent headaches and skin rashes from direct contact. Less often, workers may experience neurological effects that affect visuospatial learning, memory loss, verbal learning and reduce psychomotor speed from both acute or continuous exposure.

Microbial infestation can sicken unsuspecting workers even when a building structure appears to be well-ventilated and climate controlled. As mentioned earlier, some select microbes produce mycotoxins when actively growing on building substrates or stored contents, which can be dangerous to human health. Exposure in air can cause allergic reactions, fungal or bacterial infections, asthma, hypersensitivity pneumonitis and respiratory conditions. In another study, Canadian researchers found 270 different species of microbes in different buildings.

Substances known as microbial volatile organic compounds are powerful chemical irritants associated with microbial exposure from both actively growing fungi and bacteria. These vapors are released directly into air by fungal and bacteria, often giving off strong or unpleasant odors. Exposure has been associated with clinical symptoms like fatigue, nausea, headaches, dizziness and sinus irritation. Severe reactions may occur among workers whom are exposed to large amounts of these microbes in occupational settings, such as farmers working around moldy hay. Severe reactions may include fever and shortness of breath.

In 2004, the Institute of Medicine found there was sufficient evidence to link indoor exposure to fungi with upper respiratory tract symptoms, cough and wheezing in otherwise healthy people; with symptoms in people with asthma and allergy; and hypersensitivity pneumonitis in individuals susceptible to an immune-mediated condition. Well, why is all of this information important? Moving companies should protect their workers from sources of microbial growth before handling, packing, transporting or shipping residential or commercial items. In our case study, our team was not able to determine causation for the microbial growth due to delays in filing the claim.  

Microbial growth in warehouses, trucks and shipping containers can be a big problem and expose workers to airborne and surface contamination. Unfortunately, microbial growth can grow for long periods of time without being detected. Workers are exposed without being aware of the concern. Excess dampness can linger inside a truck, cargo hold or shipping container and the microbial growth can form of woods, fabrics and textiles, foodstuffs, paper and cardboard. Storm water can dampen the inside of the trailer bed or shipping container. Condensation can form inside shipping containers dropped into a cargo hold. So here a few tips for packers, shippers and movers to protect themselves from visibly microbial contaminated commercial or household goods:

1. Inspect soft goods for suspect microbial growth, if the contents exude a musty or foul odor.
2. If the soft goods are stored in an uncontrolled climate like a basement or attic, check the contents and surrounding area for visible microbial growth before packing.
3. Lift up the mattress and box spring. Don’t move or accept these articles if visible microbial growth is discovered before packing or loading,
4. Will outdoor furniture be included in the move? Check these outdoor stored items for microbial growth before handling or packing.
5. Wear a mechanical filtered respirator, gloves and personal protective clothing when handling contents with visible microbial growth or working with excessive dirt, dust or leaf litter on the ground.
6. Cardboard boxes that are damp or wet or show a water line along the bottom or if the box is deteriorated from long-term storage on concrete should be inspected before moving them.
7. Is the commercial building or residence climate controlled? If not, check for evidence of microbial growth on the walls, ceiling or floor.
8. Reusable wooden storage units should not have large holes, defects or microbial growth.
9. Liquids in containers should not be stored with any soft goods during a move. Unless the liquids are in their original sealed unbreakable packaging, they should be transported separately, especially in large quantities or contents is considered a hazardous material.
10. Check the ambient environmental conditions during the move or time duration for delivery.
11. Trailer beds in moving trucks with wooden floors should be clean and free of leaf litter, dirt or soil and not damp or wet from adverse weather while loading and unloading goods.
12. Desiccants or moisture absorbing material can be used inside a truck trailer, storage crate or cube rental to keep the air dry. These materials will help remove excessive moisture.
13. Prevent shipping or transportation of consumer goods during extreme weather conditions or loading and unloading contents without a protective cover overhead during a storm.
14. Photograph any items with visible microbial growth during packing or unpacking and inspect the exterior of prepacked cardboard boxes in storage cubes, basements or attics.
15. Consider a right of refusal policy to handle, pack, ship, transport or store any item or container with visible microbial growth. Document all evidence in future claim or litigation.
16. Train warehouse workers, movers, shippers and haulers about the occupational health and safety concerns of microbial growth, precautions and procedures to follow if microbial growth is uncovered prior to or during a move.
17. Require workers to report any overt signs and symptoms of occupational exposure to microbial growth for proper medical treatment and workers’ compensation claim.

Before packers, movers and shippers consider their next job, ask all the right questions and get answers. Hopefully these simple tips may prevent worker exposure or a property claim. If anyone experiences recent changes in their health, seek medical attention. Sensitized or asthmatic workers should use a mechanical filtered respirator, gloves and personal protective clothing when handling or moving contents. Workers should understand how to decontaminate themselves to prevent exposure to themselves or cross contaminating the work area. For more information, read of “Mold: Worker and Employer Guide to Hazards and Recommended Controls” published in June 2015 by the U.S. EPA, National Institute of Health, OSHA, and U.S. Department of Housing and Urban Development.

Microbial growth is completely preventable if everyone considers the hierarchy of controls and all of the environmental factors that may lead to an unfortunate outcome. Workers’ compensation or medical insurance claims and lost time from work can be reduced by wearing a respirator, gloves and personal protective clothing when a hazard exists. Understanding the risks through initial and periodic training and education is essential for worker protection. Showering or washing face and hands after a work shift and using proper decontamination techniques to remove respirator and personal protective clothing are important best work practices. To help better understand these issues, OSHA offers “A Brief Guide to Mold in the Workplace.”

International shipments have a very high likelihood of microbial growth. Even if the destination agent may never have opened the freight shipment container or vaults, the shipper may hold the moving company liable for the damage of personal property if microbial growth is discovered during unpacking. The shipper may responsible for any mitigation, cleaning, remediation cost or the replacement cost of the item. Protect all parties from potential liability or covered claim by ensuring the contract with the freight forwarder specifically states which parties are responsible in the event of microbial damage. Using a “door-to-door bill lading to limit liability. Finally, consider developing a written policy, program and standard operating procedures to protect all workers.