Hexavalent chromium (also known as chrome 6) is a metal and is one type of air pollution that can cause negative health effects. Chrome 6 is a known human carcinogen. Chrome 6 does NOT have an odor. You can read more about hexavalent chromium on the Centers for Disease Control website: https://www.cdc.gov/niosh/topics/hexchrom/

Long-term exposure over years or decades to hexavalent chromium can increase the likelihood of cancer, particularly lung cancer.

No and No. In late October/early November, the highest levels of hexavalent chromium were found within three samples taken from two air quality monitors in the industrial section of town. Since then, hexavalent chromium levels at these locations have declined, but still are much higher than typical levels for our area. Further, other monitors in the industrial zone continue to be at unacceptably elevated levels for our area.

Additional sampling from around town indicate that the extremely elevated levels of hexavalent chromium are limited to a tight area within the industrial zone. Regardless of location, any elevated level of hexavalent chromium or other toxins are unacceptable. SCAQMD has continued to test additional sections of the City to ensure elevated hexavalent chromium levels are geographically limited. The City will also be looking at further testing options to confirm that high levels are not being detected in residential zones while supporting regulatory authorities to reduce hexavalent chromium sources no matter the zone.

In the City’s industrial area.  One monitor was located at Garfield Avenue and Madison Street and the other was located at Minnesota Avenue and Madison Street.

The typical level for hexavalent chromium across the entire 4-County region monitored by SCAQMD is 0.06 nanograms per cubic meter. The level measured in Compton (the closest permanent SCAQMD monitoring station to Paramount) during the most recent region-wide study of air toxics was at 0.11 nanograms per cubic meter, which is more typical of our general location in a highly urbanized area.

The common reference used is nanograms per cubic meter as represented by ng/m3 (nanograms per cubed meter). This is the value that SCAQMD uses to report on the level of hexavalent chromium identified by air monitors that have been positioned around the City.

Hexavalent chromium and total chromium emissions from chrome plating and anodizing equipment are measured by the SCAQMD METHOD 205.1 using a wet impingement train. For more details, please visit this link [PDF].

There is no defined acceptable level of hexavalent chromium emissions. The acceptable health risk for a given area is subject to many factors such as wind direction, wind speed, distance to the closest sensitive receptors (schools, residents, day care facilities, medical facilities), other toxic chemical compounds (TACs) emitting from the same facility, how many other facilities are proximate to the given area, and other factors. The determination of an acceptable level of hexavalent chromium in the specific case of Anaplex and Aerocraft, determined that 1 ng/m3 is good enough based on their own health risk assessment (HRA).

On a more general basis, in terms of concentration and sustained exposure CalEPA’s Office of Environmental Health Hazard Assessment (OEHHA) has calculated a cancer risk associated with exposure to Cr6 (hexavalent chromium) if that exposure continues for an entire lifetime. Continual exposure to 0.045 nanograms per cubic meter (ng/m3) of Cr6 from all sources combined for 30 years could increase cancer risk to 25 in a million. Exposure over shorter periods of time would be associated with much lower cancer risks. OEHHA has also developed a chronic Reference Exposure Level (REL) for Cr6. A chronic REL is a health-based benchmark that is set at a level at or below which adverse noncancer health effects are unlikely to occur in the general human population when exposed continuously over a lifetime. Levels above the REL do not indicate the health effects will occur, but rather, that the chances of these health effects occurring increase at levels above the REL. Non-cancer health effects associated with Cr6 include nasal, throat, or respiratory irritation or allergies. The chronic REL for Cr6 is 200 ng/m3 in air (0.2 μg/m3). Please see a fact sheet by OEHHA dated November 9, 2016 for more details.

No. At this time, SCAQMD monitors located in other parts of the City have measured hexavalent chromium at levels above typical background concentrations for our region, but much lower than those recorded in some industrial areas. For instance, the SCAQMD monitor located at the PUSD Administrative Offices (corner of Somerset and California) had an average measurement of 0.15 nanograms per cubic meter over the last year. The SCAQMD monitor at Salud Park (corner of Somerset and Texaco) had measurements less than 0.25 nanograms per cubic meter over a two-week period. The SCAQMD monitor located at the edge of the City’s industrial core (corner of Vermont and Madison) had measurements less than 0.5 nanograms per cubic meter over a two-month period.

Most likely. SCAQMD found two businesses it believed to be the primary sources: Aerocraft Heat Treating and Anaplex Corporation.

In regards to Aerocraft, the company and SCAQMD agreed to an administrative order, known as an Order for Abatement, that was adopted by the independent SCAQMD Hearing Board on Dec. 16. The enforceable order requires Aerocraft to immediately take 22 actions to reduce chromium 6 emissions.  In addition, if SCAQMD air monitors detect an outdoor level of hexavalent chromium above 1.0 nanograms per cubic meter, as determined by three samples, the company must shut down all equipment that could emit the cancer-causing compound.

In regards to Anaplex, the company declined to enter into an immediately enforceable administrative order. As a result, SCAQMD sought a court order to require them to immediately comply with the same conditions as those required of Aerocraft in order to protect the health of Paramount residents.  The Court ruled against SCAQMD. However, SCAQMD will return to the Independent Hearing Board on January 5, 2017 in attempt to force Anaplex into compliance.

SCAQMD is conducting a systematic air monitoring program throughout Paramount to determine if there are other sources of hexavalent chromium emissions. SCAQMD also will be monitoring for a wide range of metal emissions in selected industrial areas.

The City of Paramount assisted the SCAQMD and LA County Fire in sweeping 190 (as of 12/20/16) businesses in town to review their operations, permit status and reporting paperwork to ensure the businesses were fully compliant with various environmental laws. Of these, 143 businesses have been determined to not require permits or the businesses were in compliance. Additional follow up inspections and enforcement actions are happening.

According to State law, the SCAQMD has sole jurisdiction to adopt and enforce local air quality laws. The California Air Resources Board and the United States Environmental Protection Agency also adopt and enforce state and federal standards. Nonetheless, the City has played an active role in partnering with SCAQMD in order to enable the agency to move as fast as possible and is working to provide timely and accurate information to residents to help them understand the issues. Because the City has not been responsible for air quality, it has not had expertise in air quality issues. However, this issue has raised broader questions about environmental quality and the City Council has directed City Staff to explore a long-term strategy for monitoring environmental quality factors and supporting policies that will facilitate cleaner jobs in our community.

The City also adopted a 45-day moratorium on all new metal-related businesses in town on December 13, 2016. This means that no new metal-related businesses can open up or expand in town until the City Council lifts this ban or it expires. The City Council can extend the moratorium for up to 18 months.

The City adopted a 45-day moratorium on all new metal-related businesses in town on December 13, 2016. This means that no new metal-related businesses can open up in town until the City Council lifts this ban or it expires. Also, no existing metal-related businesses in town can expand while the ban is in place. The initial 45-day period is mandated by State law. The City Council can extend the moratorium for up to 22 months and five days.

The City has launched a new information website, paramountenvironment.com that provides links and information on a full array of environmental questions, as well as links to other resources. Additionally, the SCAQMD website (www.aqmd.gov) has a lot of information specific to air quality, including test results from the various monitoring stations and updates on enforcements actions. You can also dial into a public conference call that AQMD hosts on the fourth Tuesday night of each month at 6:30PM. The number is 866.244.8528 Access Code: 4063768.

Lastly, you can visit the California Environmental Protection Agency (Cal EPA)’s page dedicated to this issue (www.calepa.ca.gov/enforcement/paramount/) for an overview of the work of the various state and local agency partners to address pollution concerns in Paramount.

Late October 2016. As background, in late summer of 2016, SCAQMD staff reported in a Town Hall meeting the results from long-term air monitoring in another area of town that found slightly elevated readings of hexavalent chromium during the first few months of 2016. This prompted SCAQMD to deploy further air monitors in other areas of the industrial sector to identify the sources of hexavalent chromium emissions. In late October 2016, two of these monitors found the extremely high levels referenced in an earlier question. At that point, SCAQMD notified, and sought assistance from, Paramount staff on November 4, 2016. Paramount staff immediately provided the venue for the first Town Hall meeting that was held on Wednesday, November 9, 2016. Paramount staff has worked, and continues to work, with the SCAQMD by providing assistance and resources to them and all other regulatory agencies that have become involved in addressing and resolving the hexavalent chromium issue.

The City has taken numerous actions including adopting a moratorium on new metal-related businesses and expansion of existing businesses, and continues to partner closely with SCAQMD on a daily basis.

SCAQMD is conducting a systematic air monitoring program throughout Paramount to determine if there are other sources of hexavalent chromium emissions. SCAQMD also will be monitoring for a wide range of metal emissions in selected industrial areas.In addition to this, SCAQMD is monitoring in residential areas and at some schools. Lastly, for long-range monitoring, the City is planning to purchase air monitors to be set up and tested by SCAQMD. Details on that program are still pending, including details on the costs of the program and effort.

Yes. While SCAQMD is the lead agency for air regulation, there are many other established regulatory agencies (Federal, State, and Local) whose laws and rules apply to businesses. Agencies that can play a part in regulating businesses for issues related to various pollutants and toxins include: the Federal Environmental Protection Agency, California Environmental Protection Agency, California Air Resources Board, State Water Resources Control Board, California Department of Toxic Substances Control, California Division of Occupational Safety and Health, Los Angeles County Fire Department, and Los Angeles County Department of Public Health.

The City’s water supply is deep underground at nearly 1,200 feet. That is supplemented by imported water from the Metropolitan Water District that most typically comes from the Colorado River or Northern California. In all such cases, the likelihood of hexavalent chromium entering the water supply is very low.

The water is tested for hexavalent chromium levels every three years as part of the Federal water quality standards. At no point in the history of testing Paramount water supply has hexavalent chromium been found above acceptable trace amounts. However, in light of recent events related to hexavalent chromium emissions and out of an abundance of caution, the City is testing hexavalent chromium levels in the City’s water supply more frequently to ensure the water supply is not being impacted by hexavalent chromium emissions.

Test results from December 2016 are posted on paramountenvironment.com and can be found here [Hexavalent Chromium Test Results].

The District and the City are two separate government agencies but share a long history of cooperating to address community challenges. Neither the District nor the City are experts in air quality matters, and both of these organizations rely on the expertise of environmental regulators to provide information and enforcement on air quality. The City is supportive of all testing that SCAQMD is seeking, especially when it concerns testing the air near our schools.

SCAQMD has indicated that those monitors will remain in place throughout the enforcement period associated with the abatement orders that have been entered into by Anaplex and Aerocraft heat Treating. This is likely to be between one to two years.

Based upon additional scientific evidence and business conditions at the time that SCAQMD concludes that ongoing monitoring is no longer required to enforce their abatement order, the City of Paramount may step in as needed to sustain the monitoring in these areas to provide additional public confidence and oversight on air quality concerns in this area of the city.

When the South Coast Air Quality Management District (SCAQMD) began their investigation into the elevated levels of hexavalent chromium found by their long-term air quality monitoring efforts, the City of Paramount provided a list of metal-related businesses to assist the District in identifying the source of the carcinogen. Metal-related businesses were defined as: grinding, sanding, plating, electroplating, welding, deburring, heating, heat treating, straightening, forming, machining, cutting, rolling, pressing, forging, fabricating, polishing, milling, swaging, cooling, conversion coating, anodizing, passivation, and spray-coating operations.

This list, taken from Paramount’s permit database, contained 86 facilities located throughout the city. SCAQMD then added businesses of various types to this list of entities so as to inspect all facilities within their jurisdiction. These additions included businesses near Aerocraft Heat Treating and Anaplex Corporation, regardless of whether the business was metal-related, as well as businesses identified by community members who discovered these facilities primarily through Internet searches for metal-related businesses noted to be in the city. Further, the list grew as SCAQMD added facilities by identifying them through permits issued in Paramount for metal-related businesses. As a result of combining all these sources of information, the list of entities to be inspected grew to a total of 194 facilities and businesses. Hence, when SCAQMD states that they had investigated 194 businesses, this means that the District reviewed a list of 194 business entities that had been assembled from several sources and not all of which were metal-related.

Many of these 194 properties/businesses that were reviewed by SCAQMD were found to be either out of business, not located in Paramount, or not involved in metal-related activities. For example, SCAQMD and City Staff determined the following thirteen businesses were no longer operating: Hanks Sheet Metal, JM Metal Polishing, California Precision Deburring, Leavitts Metal Finishing, Luisteel Welding, Western Integrated Materials, Rosenberg Metals, United Sheet Metal, Aluminum Interior Moldings, El Tigre Metal Polish, Best Western Rolling, and E.S. Scales/Somerset Steel.

After extensive investigation, City Staff removed from the list all businesses that were not metal-related, any duplicate listings, and the entities that were no longer operating, listed above. The final number of metal-related facilities licensed to do business in Paramount totals 85, which amounts to 3% of total business licenses issued in the city. Of the 85 businesses, the City and SCAQMD determined that 68 of those businesses do not require SCAQMD permits for metal-related operations (examples include metal dealers, metal screw sales shops, metal supply shops, metal etching companies). To be clear, these businesses may have an SCAQMD permit for a backup generator or other equipment unrelated to metal processing.

The remaining 17 facilities require SCAQMD permits for metal-related processing (as of February 16, 2017).

To summarize: 194 names or locations were added onto a list assembled from multiple sources that was reviewed by SCAQMD; each name or address was investigated. After the investigation was completed, it was determined that there are 85 metal-related businesses in the city limits of Paramount. Of those 85 metal-related businesses, 68 do not require any permits from SCAQMD for metal-related processing. In total, 17 businesses do require SCAQMD permitting for metal-related work.

In general, the uptake of metals by plants is not expected to pose a health risk hazard to consumers. However, the accumulation of metals on the outside of garden foods is more difficult to predict. The Los Angeles County Department of Public Health recommends washing of all foods, as well as hand-washing, to remove any residual soil. For more information, please refer to “Soil and Water Testing Guidelines for Home and Community Gardens.”

According to the South Coast Air Quality Management District (SCAQMD), the sample for Site #19 on May 1st was not collected: it was used for an off-schedule sample that was collected on May 3rd. Due to the off-schedule sample on May 3rd, the typical May 4th sample was not collected. The normal schedule for sampling will resume on May 7th. SCAQMD is preparing another sampler so they do not have to alter the schedule for Site #19 to collect on off-schedule sample in the future.

Additionally, the portable City samplers should not have been marked on the ambient data spreadsheet. They will be removed, as the City monitor would not have been at Site #19 after the initial sample. The portable samplers are being implemented into the rotation of SCAQMD samplers. The agency will clarify this on their Expanded Monitoring Data and Map spreadsheet.

There has been some recent news coverage on the Tesoro Refinery’s planned expansion in the City of Carson. Since the beginning of the project, several community members in Carson have expressed various environmental concerns. Both the Carson Tesoro refinery and Paramount’s hexavalent chromium air quality concerns pose environmental challenges, which are unique to their specific situations. While the challenges are quite different, how these cities are responding have their own distinct merits. The following is an attempt to outline those key differences.



  • The City of Carson has sued SCAQMD for approving a project to allow Tesoro to integrate its Wilmington refinery into the Carson refinery, making Carson the largest petroleum refinery on the West Coast. The City will work with the agency moving forward.
  • The City of Paramount has been working closely with SCAQMD since fall 2016 to reduce chrome 6 emissions from Anaplex and Aerocraft, and other facilities in the future. Monitoring efforts are ongoing to ensure lasting reduction in emissions.
  • The City of Carson states that resident and city concerns were not taken into consideration while preparing the environmental assessment for the Tesoro project. However, this project is in its initial phases; SCAQMD may have plans to gather community input and discussion.
  • The City of Paramount has worked to ensure that community and city concerns are considered by the SCAQMD. Moreover, SCAQMD has actively responded to the situation to investigate and reduce emissions.
  • The City of Carson believes that local pollution effects were not considered in the Tesoro project. The City will need to further discuss this topic with SCAQMD as the project advances.
  • The City of Paramount and SCAQMD have led an unprecedented cooperative multi-agency investigation into hexavalent chromium emissions and have both dedicated significant resources to address this issue.
  • The City of Carson believes that the Tesoro project will increase pollution in the city.
  • The City of Paramount is working with SCAQMD to develop and adopt new regulations with the goal of ensuring that there is a reduction of pollutants, including chrome 6. These rules may benefit other communities in the future with better environmental standards.
  • Opponents of the Tesoro project claim that outdated technology related to pollution monitoring was used in the environmental analysis.
  • The City of Paramount, the California Air Resources Board, and SCAQMD have worked to ensure that air monitoring devices are technologically advanced.
  • The City of Carson and the Tesoro Refinery came to an agreement that would allow the City to receive $45 million to, among other things, make public improvements around the refinery.
  • The City of Paramount is currently working on developing changes to the municipal zoning code that could include fees paid by industry.  Revenue from these fees could pay for ongoing air monitoring and other environmental programs.

This is just a brief comparison of the two situations. Should you have further questions or comments, we encourage you to write to us via our Contact page.