17.3 Chemical Transport, Storage & Handling in Distribution Operations
Key Takeaways
- Chlorine gas cylinders must be secured upright with valve protection caps in place whenever they are not connected, and moved only with proper equipment.
- Ton containers are positioned so the two valves are vertically aligned, with the upper valve drawing gas and the lower valve drawing liquid.
- Safety data sheets must be accessible to every worker who handles a chemical, and the labeling requirements follow the Hazard Communication Standard.
- Emergency eyewash and safety shower units must be reachable within about ten seconds of travel from a hazard and must be flushed on a routine schedule.
- Ammonia vapor identifies a chlorine leak by forming a white cloud, and water must never be applied to a chlorine leak.
17.3 Chemical Transport, Storage & Handling in Distribution Operations
Distribution operators handle treatment chemicals at remote booster stations, wells, and storage sites, often alone and without the engineered ventilation and containment a treatment plant provides. That combination makes chemical handling one of the highest-risk activities in the job.
Gas Chlorine
Gas chlorine remains in service at many well sites and booster stations because it is inexpensive and does not degrade in storage.
| Container | Capacity | Handling |
|---|---|---|
| 150 lb cylinder | 150 lb | Upright, chained or secured, valve protection cap on when not connected, moved by hand truck |
| Ton container | 2,000 lb | Horizontal on trunnions or a cradle; moved with a rated hoist and lifting beam |
Non-Negotiable Rules
- Store and use cylinders upright and secured. An unsecured cylinder that falls can shear its valve, converting the cylinder into an uncontrolled release and a projectile.
- Valve protection caps stay on whenever the cylinder is not connected — during storage, transport, and any movement.
- Never lift a cylinder by the valve or the protection cap.
- Never use a magnet or a sling around the body; use the proper hand truck or, for ton containers, a lifting beam engaging the container lugs.
- Ton containers are positioned with the two valves vertically aligned. The upper valve draws gas, the lower valve draws liquid. Drawing liquid chlorine into equipment designed for gas causes a violent expansion and equipment failure.
- Never apply heat to a cylinder to increase withdrawal rate.
- Use new gaskets on every connection, and never reuse a lead washer.
- Do not store chlorine with ammonia, hydrocarbons, or organics.
Withdrawal Rates
A cylinder withdrawing gas cools as the liquid evaporates. Exceeding roughly 40 lb per day from a 150 lb cylinder, or 400 lb per day from a ton container at normal room temperature, causes frost formation and a falling withdrawal rate. Manifolding multiple containers is the correct solution; heating the container is not.
Leak Response
[!WARNING] Use ammonia vapor to locate a chlorine leak. A squeeze bottle or swab of aqueous ammonia held near a joint produces a white cloud of ammonium chloride where chlorine escapes. Never spray water on a chlorine leak — chlorine and water form hydrochloric and hypochlorous acids that aggressively corrode the container and rapidly enlarge the opening, turning a small leak into a major release.
Chlorine Institute emergency kits: Kit A for 150 lb cylinders, Kit B for ton containers, Kit C for tank cars and trucks. Kits must be present where the corresponding container is used, and personnel must be trained on them.
Self-contained breathing apparatus must be stored outside the chlorine room so it can be donned before entry. Chlorine gas is heavier than air and collects at floor level, so chlorine room ventilation exhausts low, and the room requires continuous gas detection with local and remote alarm, an exterior-opening door with a viewing window, and a light switch and ventilation control outside the door.
Sodium Hypochlorite
Hypochlorite avoids the acute gas hazard but is not benign.
- Corrosive to skin and eyes; requires splash goggles, face shield, gloves, and apron.
- Off-gasses oxygen, which causes pump vapor lock and requires tank venting.
- Decomposes with heat, light, and time, so shaded, ventilated, opaque storage and rapid stock turnover are needed — a particular concern in Arizona.
- Incompatible with acids (liberates chlorine gas) and with ammonia (produces chloramine vapors).
- Attacks many metals; use compatible piping and containment.
Ammonia for Chloramination
- Aqueous ammonia (ammonium hydroxide) — the common choice; corrosive, with a strong pungent vapor. Store cool; vapor pressure rises steeply with temperature.
- Ammonium sulfate — a dry salt, the safest form, dissolved on site.
- Anhydrous ammonia — a severe inhalation hazard, and most utilities have moved away from it.
Never store ammonia near hypochlorite or chlorine. The two must be in separate containment with separate, non-interchangeable fill connections.
Hazard Communication
The OSHA Hazard Communication Standard requires:
| Element | Requirement |
|---|---|
| Written program | Describes how the employer meets the standard |
| Chemical inventory | A list of hazardous chemicals present |
| Safety data sheets (SDS) | Readily accessible to every worker on every shift — including at remote sites |
| Labels | Product identifier, signal word, hazard and precautionary statements, pictograms, supplier identification |
| Training | Before initial assignment and whenever a new hazard is introduced |
SDS Section 4 (first aid), Section 6 (accidental release), Section 7 (handling and storage), and Section 8 (exposure controls and PPE) are the sections operators use most. A binder locked in an office 30 miles from a booster station does not satisfy "readily accessible."
Storage, Containment, and Segregation
- Secondary containment sized to hold at least the largest container, commonly 110 percent.
- Segregate incompatible chemicals in separate containment so a spill of one cannot reach the other.
- Unique, non-interchangeable fill connections, distinctly labeled and physically separated.
- Ventilation appropriate to the chemical, exhausting low for gases heavier than air.
- Security: locked, signage posted, access controlled. Chemical storage at unattended remote sites is a recognized security concern.
- Spill kits appropriate to the chemicals present, with absorbent and neutralizing material.
Emergency Equipment
| Equipment | Requirement |
|---|---|
| Emergency eyewash and safety shower | Within about 10 seconds of travel from the hazard, on the same level, along an unobstructed path; flush weekly, inspect annually |
| Gas detection | Continuous where gases are used, with local audible/visual and remote alarm |
| Respiratory protection | Appropriate to the hazard; fit-tested, with a written respirator program and medical clearance |
| Emergency contacts posted | At every chemical storage location |
| Spill kit | Matched to the chemicals present |
[!IMPORTANT] A chemical splash to the eye requires 15 minutes of continuous flushing, which is why a plumbed eyewash is required rather than a squeeze bottle. Personal eyewash bottles supplement but do not replace a plumbed unit. Weekly activation matters because stagnant water in an unused eyewash line grows organisms, and flushing an eye with contaminated water compounds the injury.
An operator finds a small chlorine leak at the valve connection of a ton container. What is the correct method to confirm the leak location?
A ton container of chlorine is installed on its trunnions with the two valves oriented horizontally side by side rather than vertically. Why must this be corrected?
An emergency eyewash station at a remote booster station has not been activated in eight months, though it is plumbed and functional. What is the concern?