Industrial hygiene in Glendale: ammonia and the cold-storage corridor

Much of the West Valley's industry is refrigerated, and that one fact changes what matters most for many of the large sites out here.

Our field is industrial hygiene, the discipline behind workplace air monitoring and noise surveys.

Ammonia refrigeration is the West Valley question

Glendale and the corridor around it hold a great deal of food processing, cold storage and refrigerated distribution. The corridor takes in Tolleson, Goodyear, and the I-10 and Loop 303 distribution spine. That means industrial ammonia systems, and it means working out how much ammonia you actually hold.

Anhydrous ammonia comes under OSHA's Process Safety Management standard at 10,000 pounds. The common mistake is to count only the largest vessel.

The standard applies to a process, and interconnected vessels count as one process. That takes in the receiver, accumulators, intercooler, surge drums, evaporator coils and the ammonia sitting in the piping. Add that up honestly, and very few distribution-size systems come in under 10,000 pounds. EPA has a Risk Management Program at the same figure, which is a separate rule with a separate filing.

Process safety work is outside the four fields we work in. Our part is air monitoring.

The air monitoring side is smaller, and still worth doing properly. OSHA's permissible exposure limit (PEL) for ammonia is 50 parts per million (ppm). Two other organizations set lower numbers. ACGIH, the professional body that publishes the threshold limit values (TLVs), and NIOSH are both at 25 ppm, with a short-term value of 35 ppm.

A fixed gas detection system in the engine room is there to find leaks. It is not a record of what one person breathed, such as the technician who spent 40 minutes on a coil.

→ Ammonia air monitoring · Food and beverage plants

The two hazards inside a big distribution building

Carbon monoxide. Picture propane forklifts in sealed rooms, where doors stay shut to hold the temperature and engines run rich when cold. Refrigerated warehouses are one of the places where carbon monoxide is most often missed. The OSHA PEL is 50 ppm, and the ACGIH TLV is 25 ppm.

The battery charging room. Electric fleets moved the problem without removing it. Charging lead-acid batteries generates sulfuric acid mist. The OSHA PEL is 1 milligram per cubic meter of air (mg/m³). The ACGIH TLV is 0.2 mg/m³, measured as the thoracic fraction, the part of the mist that reaches the chest airways.

Sampling this mist takes a mixed cellulose ester filter with a backup pad behind it, because the mist does not all stay on the filter.

It is worth being exact about where that comes from. OSHA's current sampling instructions for sulfuric acid call for a pad treated with sodium carbonate, while the text of OSHA's analytical method ID-113 describes a plain cellulose pad. ID-113 is also a partially validated method. A bare filter holder from a metals kit will still give you a number, but it will be a low one.

→ Carbon monoxide monitoring · Acid mist monitoring · Noise surveys

Aerospace and defense support

Luke Air Force Base sits just west of Glendale, in unincorporated Maricopa County outside the city limits, with a Glendale mailing address. It is the Air Force's main F-35A pilot training base and the home of the 56th Fighter Wing.

Maintenance, ground support and base services work around a base like that brings the hazards of aviation work:

• Hexavalent chromium, from chromate conversion coatings and primers
• Isocyanates, from polyurethane topcoats
• Solvents, in surface preparation and parts cleaning
• High noise levels, from engines and ground equipment

Hexavalent chromium and isocyanates are both easy to sample incorrectly. For hexavalent chromium, the right filter depends on the source: plating is one case, and paint and weld fume is another. Isocyanates need a derivatizing filter, which is a chemically treated filter. An ordinary filter comes back “none detected” no matter what is in the air.

→ Hexavalent chromium air sampling · Isocyanate air sampling · Aerospace plants

Two Maricopa County details worth getting right

Your air permit is a county permit. For most sources in the Phoenix metro area, the Maricopa County Air Quality Department issues the permit, not ADEQ, the Arizona Department of Environmental Quality. Only three Arizona counties run their own air programs: Maricopa, Pima and Pinal. A compliance obligations register (the list of laws and rules you must follow) that names only the state agency is wrong for Glendale.

The metro area is also a PM10 nonattainment area, which means it does not meet the federal air standard for dust particles. Maricopa County's fugitive dust rules sit on top of normal permits and reach sites with large unpaved yards, haul routes and ongoing earthmoving. West Valley sites with room to grow are exactly the ones this catches, and it is usually found during construction, not before it.

We do not handle air permits or dust rules. We mention them here so that your register is accurate.

→ How to build a compliance obligations register

What we do here, and where we are

We work in four fields here:

• Tier II chemical inventory reporting (due March 1)
• Form R / TRI reporting (due July 1)
• Air monitoring surveys and noise surveys
• ISO consulting for environmental management (ISO 14001) and for occupational health and safety (ISO 45001)

If you file a Form R, Arizona also requires a pollution prevention plan and Toxic Data Report through myDEQ on the same July 1 deadline.

We do not keep a Glendale branch, and we work from one Arizona office. Glendale is a short drive, and most jobs are 1 to 3 days at your facility. We arrive before the shift to calibrate our equipment, sample through the shift, and calibrate again at the end.

→ Where we work