Aerocraft in Paramount Temporarily Suspends Operations

January 19, 2017

Aerocraft Heat Treating Co., Inc. – a metal-finishing facility in Paramount -- has temporarily shut down all operations emitting the toxic compound hexavalent chromium to comply with an administrative order designed to protect public health.

“This order is working  just as intended by preventing the facility from emitting potentially harmful levels of this toxic compound,” said Wayne Nastri, executive officer for the South Coast Air Quality Management District. “Aerocraft will not be able to resume operations until SCAQMD monitoring data shows that hexavalent chromium levels have dropped below the level specified in the order.”

Aerocraft, at 15701 Minnesota Ave., today shut down all equipment with the potential to emit hexavalent chromium because SCAQMD air monitoring data found levels of the compound above a trigger threshold of 1.0 nanograms per cubic meter. The level is an average of three samples collected over a period of about a week. The threshold, agreed to by Aerocraft, was specified in an administrative order adopted by the independent SCAQMD Hearing Board.

The following table shows recent levels of hexavalent chromium at a SCAQMD monitor just downwind of Aerocraft:



Hexavalent Chromium level (nanograms/cubic meter)

Jan. 7


Jan 10


Jan 13





Aerocraft will not be able to resume operations of any equipment with the potential to emit hexavalent chromium until SCAQMD determines that the average of three most recent samples, collected over about one week, are below 1.0 nanograms per cubic meter.

SCAQMD monitors deployed in other areas of Paramount, but not in close proximity to Aerocraft or Anaplex Corp. -- another metal-processing facility at 15547 Garfield Ave. -- recently have reported levels of the compound below 1.0 nanograms per cubic meter.

SCAQMD, in conjunction with the California Air Resources Board, also is monitoring air quality at six schools in Paramount. Recorded levels at those schools have been below 0.3 nanograms per cubic meter since sampling started on Dec. 23, 2016. Sampling will also be conducted at other schools in Paramount.

Aerocraft’s curtailment today is the first since the Hearing Board adopted its order on Dec. 16, 2016.

SCAQMD found last fall that Aerocraft and Anaplex Corp. were the source of high levels of hexavalent chromium emissions through an exhaustive and fast-paced investigation including:

  • An unprecedented, intensive monitoring campaign that deployed multiple air monitors in an industrial area of Paramount and found high levels close to the facilities; and
  • Emissions tests of equipment inside the facilities that also found high levels of the compound.

Hexavalent chromium is a potent human carcinogen associated with lung cancer when inhaled over long periods of time, typically years to decades.

SCAQMD has required Anaplex and Aerocraft to develop health risk assessments and risk reduction plans under the state’s Toxic Hot Spots program to ensure these facilities reduce all toxic air contaminants to health-protective levels. While some actions may take longer to implement, the facilities will have to start executing many risk reduction measures over the next few months.

Members of the public can find information on SCAQMD’s air monitoring and enforcement activities in Paramount at

In addition, the public and the news media are invited to join a weekly conference call on the status of SCAQMD’s Paramount activities every Tuesday starting at 6:30 p.m. To participate, call 866-244-8528 and use the passcode 4063768.

A simultaneous Spanish translation of the call is available by calling 888-394-8197 and using the passcode 9891238. The calls are listen-only, however questions may be submitted by email during the call to Questions are answered during the call in the order received.

The SCAQMD is the air pollution control agency for Orange County and major portions of Los Angeles, San Bernardino and Riverside counties.