Industrial hygiene in Peoria: before and after the Amkor campus

Peoria is the one Arizona city where the right question about air monitoring and noise surveys changes completely between now and 2028.

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

Amkor, and two very different sets of hazards

Amkor Technology broke ground on a $7 billion advanced packaging and test campus in Peoria on October 6, 2025. Production is expected in early 2028.

That timeline creates two separate regulatory settings, and the standards for each are structured differently.

Right now it is a construction site. That puts it under OSHA's construction standards, which are a separate set with their own structure and not the general industry standards with a different cover page.

From 2028 it is an advanced packaging plant. A base of suppliers and service firms will grow around it, and all of that is what OSHA calls general industry.

The construction phase: construction standards, not general industry standards

The most useful thing to know about silica dust on a project like this is the difference between the two silica standards. The construction standard has a shortcut, known as Table 1. The general industry standard does not.

Table 1 lists construction tasks and, for each one, the dust controls and respiratory protection to use. An employer can follow the table instead of measuring worker exposure. The listed tasks include:

• Handheld saws
• Walk-behind saws
• Drills
• Grinders
• Jackhammers
• Rig-mounted core drills

If you fully implement the listed control, you do not have to sample for that task. The general industry silica standard has no comparable table anywhere.

A specialty contractor cutting slab on this site therefore has a real choice. One path is to follow Table 1. The other, which OSHA calls the alternative exposure control method, uses other controls plus air sampling. The choice affects cost, so it should be made deliberately and not by default.

The rest of the construction-phase list:

• Welding fume and hexavalent chromium on stainless steel process piping
• Diesel particulate matter from equipment fleets inside an enclosed structure
• Confined space entry, under OSHA's construction standard for confined spaces
• Noise, under the construction noise standard. Its permissible exposure limit (PEL) is 90 decibels (dBA).

The construction noise standard has far less detail than the general industry noise standard, but it is not silent on protecting hearing. In every case where sound levels exceed the values it lists, it says a “continuing, effective hearing conservation program” shall be administered.

That is a firm requirement, and OSHA has consistently treated audiometric testing as part of an effective program. What the construction standard lacks is the step-by-step detail:

• A defined action level
• A set schedule for audiometric testing
• The follow-up steps after a standard threshold shift (STS), a measured drop in hearing

It does not lack the duty itself.

One more point applies to sites with many employers. The duty to measure exposure falls on the employer of the exposed workers. A subcontractor cannot rely on the general contractor's program to meet its own duty, and OSHA's multi-employer citation policy does not favor that assumption.

→ Silica exposure monitoring · Welding fume monitoring · Hexavalent chromium air sampling

After the plant opens: what advanced packaging involves

Packaging and test is not the same as wafer fabrication, and the hazards are not the same list.

The process steps include die attach, molding, plating, wafer thinning and dicing, flip-chip and wire bond. They bring:

• Acids and solvents in plating and cleaning lines
• Epoxy mold compound with silica filler, which raises a dust question
• Flux fume and solder in the steps that connect the chip
• Specialty gases in some steps
• Noise from vacuum pumps, chillers and mechanical equipment, which is often overlooked in an industry that thinks of itself as a cleanroom.

The chip plants and campuses have large EHS (environmental, health and safety) staffs of their own. The suppliers further down the chain do not. Those suppliers, which the industry calls Tier-2 and Tier-3, are where the requirements land.

The requirements include an expectation of certification to two international standards:

• ISO 14001, for environmental management
• ISO 45001, for occupational health and safety management

Arizona's semiconductor customers now write that expectation into their supplier standards.

→ Electronics and circuit board assembly · Semiconductor and electronics plants · ISO 14001 consulting

Why timing matters

If you are a supplier or service firm that expects to work on or around this campus, the useful time to collect your baseline exposure data is before the process is locked in, at the qualification and pilot stage. Engineering controls such as ventilation are still inexpensive to change at that point.

If you wait until after production ramps up, you are documenting a problem and no longer designing it out.

Practical notes

Peoria is in Maricopa County, so for most sources air permits come from the Maricopa County Air Quality Department, not from ADEQ, the Arizona Department of Environmental Quality. We do not handle air permits, but this is a detail to get right in your register of compliance obligations, where the state agency is the wrong entry for a Peoria site.

Facilities that file Form R, the annual federal Toxics Release Inventory (TRI) report, also owe Arizona a Toxic Data Report on the same July 1 deadline, plus a pollution prevention plan.

We work from one Arizona office, so for us Peoria is a short drive and not a major trip.

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)

→ Where we work