Ferrous chloride is a salt widely used in water and wastewater treatment and chemical synthesis. It exists as a greenish-white solid or a pale green aqueous solution. Improper storage risks chemical degradation, leading to a loss of effectiveness. Maintaining the integrity of this reactive chemical requires strict adherence to specific storage and handling protocols.
Chemical Stability and Degradation Factors
The instability of ferrous chloride dictates storage conditions due to its high reactivity with moisture and oxygen. Ferrous chloride is highly hygroscopic, meaning both solid and concentrated solution forms readily absorb water vapor from the air. This absorption leads to caking in the solid or unwanted dilution of the solution, altering the chemical’s concentration and reactivity.
Exposure to oxygen, especially with moisture present, is the primary threat to the compound’s function. The ferrous ion (\(\text{Fe}^{2+}\)) is easily oxidized to the ferric ion (\(\text{Fe}^{3+}\)), forming ferric chloride (\(\text{FeCl}_3\)). This transformation is visually noticeable as the material changes color from greenish-white to a yellow or brown hue. Since ferrous chloride is often used as a reducing agent, this oxidation renders the product ineffective.
Elevated temperatures significantly accelerate the rate of oxidation and decomposition. Storing the chemical in locations that experience high heat or direct sunlight will rapidly diminish its quality. Understanding these degradation factors forms the basis for establishing proper storage requirements.
Container and Environmental Requirements
Selecting the correct container material prevents chemical degradation and corrosion. For ferrous chloride solution, materials like high-density polyethylene (HDPE), crosslinked polyethylene (XLPE), or fiberglass are recommended due to their resistance to the corrosive chloride salt. Uncoated metallic containers, especially stainless steel and aluminum, must be avoided because the acidic solution will rapidly corrode them, causing leaks and contamination.
Containers must have tightly sealed, fume-tight lids to create an airtight barrier. This seal protects the hygroscopic material from absorbing moisture and prevents oxygen from initiating oxidation. For high-purity or anhydrous material, storage under an inert gas blanket, such as nitrogen or argon, or using a desiccated storage cabinet, is necessary to completely exclude air and moisture.
The ideal storage environment should be cool, dry, and well-ventilated, with temperatures maintained between \(15^\circ \text{C}\) and \(25^\circ \text{C}\) (\(59^\circ \text{F}\) and \(77^\circ \text{F}\)). Containers must be stored away from direct sources of heat or light, including sunlight and heating vents. Every container must bear a clear, durable label that includes the chemical name, concentration, date of receipt, and appropriate hazard warnings.
Safety Handling and Emergency Procedures
Interaction with ferrous chloride requires appropriate Personal Protective Equipment (PPE) to mitigate health hazards. Handlers should wear chemical-resistant gloves, safety goggles or a face shield, and protective clothing to prevent skin and eye contact. The solution is corrosive and can cause severe irritation or chemical burns upon contact.
Storage locations must be segregated from incompatible materials to prevent dangerous chemical reactions. Ferrous chloride should never be stored near strong oxidizing agents, strong bases, or reactive metals like potassium and sodium. Adequate ventilation must be maintained in the storage area and during handling, as the chemical can release corrosive fumes, especially if hydrolysis occurs.
In the event of a spill, immediate action is required, starting with isolating the area and donning appropriate PPE. Small spills of solid material should be carefully swept up to avoid creating dust and placed into a closed container for disposal. Liquid spills must be contained using inert absorbent material and then neutralized, often with a weak base, before cleanup.
For any skin or eye contact, the contaminated area must be flushed immediately with large amounts of water for at least 15 minutes. Medical attention should be sought promptly following decontamination.