By Daniel Theobald, "Wastewater Dan"
Substances regulated or substances unregulated may ultimately impact the environment, health, and water supply of others. The following safety considerations are advised for those who store, handle, or transport potentially dangerous substances.
- Exposure Pathway
The exposure pathway of any substance is an important consideration in determining appropriate procedures. An exposure pathway refers to the way a person can come into contact with any substance.
There are three basic exposure pathways: inhalation, ingestion, or direct contact.
The degree or extent of exposure is determined by measuring the amount of any substance at the point of contact.
- Health And Ecological Effects
Health and ecological effects can result from exposures described above. Common ways in which anyone can become exposed to substances include:
- Groundwater and surface water – Exposure will occur if people drink contaminated groundwater or surface water, accidentally ingest it while swimming, or if it comes into contact with their skin (e.g., in the shower, while swimming, etc.).
- Soil, sediment, and dust – People will be exposed to any substance in soil, sediment, or dust if they accidentally ingest it (e.g., the contaminants land on their food), if they breathe it in (especially dust), or if their skin comes into direct contact. Because of their play habits, children are highly susceptible to exposure through these pathways.
- Air – When the any substance takes the form of vapors or is absorbed by particulate matter, the simple act of breathing can expose people. In some cases, a person's skin can absorb a hazardous substance in vapor form, although inhalation is considered the greater threat.
- Food – Eating food that has been contaminated is another common exposure route. In some cases, food found on people's plates may be contaminated as a result of direct exposure to any substance. In other cases, food contamination can occur further down the food chain. For example, any substance can collect in the fatty tissues of animals that ingest contaminated plants. The contamination can then be transferred to the animals' natural predators, and eventually to people.
Health effects of exposure for affected communities may include skin and/or eye irritation, difficulty breathing, headaches and nausea, or other types of illness. Some substances may cause even more severe effects.
Ecological effects can be just as devastating: killing organisms in a lake or river, destroying animals and plants in a contaminated area, causing major reproductive complications in animals, or otherwise limit the ability of an ecosystem to survive.
Some substances produce toxic effects in humans or the environment after a single, episodic release. These toxic effects are referred to as the acute toxicity. Other substances produce toxic effects in humans or the environment after prolonged exposure to the substance, which is called chronic toxicity.
- Considerations Unique To Specific Substances
Handling, storing or transporting substances in bulk may require unique consideration according to the specific substance. Such considerations include the following:
- Location of storage (inside or outside) – material compatibility, volume on hand, lighting, dikes, labels
- Transportation method (rail car or tank truck) – material compatibility, Department of Transportation (DOT) hazardous materials (hazmat) placards
- Bulk chemical unloading – ensure written procedures, bill of lading, lockout/tagout, hazmat placards, appropriately located safety shower
- Personal protective equipment (PPE) – protection from route of entry (eyes, mouth, nose, open skin) and skin contact
- Spill response – ensure appropriate spill reporting, reliable spill containment, documented spill containment plan procedures (onsite and given to necessary authorities), emergency phone numbers
- Bulk Storage
It's vitally important to maintain a high level of safety when substances are in storage. Substances may be out of sight but should never be out of mind. Storing substances safely includes an understanding of potential hazards as follows:
- Fire and explosion – preventing a substance from exposure to temperatures at which it could ignite (flammability limit) or explode (explosive limit).
- Sudden release of pressure – for instance, if a tank of compressed gas is punctured
- Reactivity – fire, explosion, or the release of dangerous gases that can result from contact between particular chemicals and certain other chemicals or air or water
- Physical and chemical characteristics – precaution against a substance changing form from a liquid to a breathable gas or vapors that could be soluble in water; specific gravity – whether a substance will dissolve or sink in water – could be crucial if there's a spill that puts water supplies at risk
- General considerations – keeping passageways clear and in good repair, with no obstructions, and free from accumulation of materials that promote tripping, fire, explosion, or the presence of pests
For anyone handling, storing, or transporting substances, these are essential considerations to protect environmental surroundings and specifically water supplies, such as those affected by the January 8, 2014 chemical spill in West Virginia and the February 2, 2014 coal ash leak in North Carolina.
About the Author:
Known in the industry as “Wastewater Dan,” Daniel L. Theobald, proprietor of Environmental Services, is a professional wastewater and safety consultant/trainer. He has more than 24 years of hands-on industry experience operating many variants of wastewater treatment processing units and is eager to share with others his knowledge about water conservation. (www.Conserve-On-Water.com).