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Located near a benzene emitting refinery? Use this tool to find out!

Oil refinery against the background of blue skies

Oil refinery against the background of blue skies Exposure to benzene can pose several health risks and may cause acute or chronic health effects, depending on the level and duration of exposure. Benzene is a known carcinogen and can cause cancer, particularly leukemia and other blood disorders, even at low levels of exposure over long periods. Other potential health effects of benzene exposure include:

  • Damage to bone marrow, which can lead to decreased red blood cells, white blood cells, and platelets.
  • Irregular heartbeats, rapid heart rate, and low blood pressure.
  • Neurological effects such as dizziness, headaches, tremors, confusion, and loss of consciousness.
  • Skin irritation and chemical burns, particularly from prolonged or direct contact.
  • Reproductive effects, including decreased fertility and menstrual irregularities.

This compound is so detrimental to health that OSHA (Occupational Safety and Health Administration) has set a permissible exposure limit (PEL) for benzene in the workplace. But community exposure to benzene can come from many sources, such as cigarette smoke, gasoline, and industrial operations.

Refineries are one of the biggest emitters of benzene in the United States, and often exceed permitted limits. Are you downwind of one of these facilities? If you are unsure, the EPA has a great tool to locate refineries and view fence line monitoring data. Fence line data is what it sounds like – each facility has monitors located around the outside perimeter of its footprint. Unfortunately, it’s not the most intuitive website, and works best on a desktop/laptop.

Here’s a walkthrough of using the tool:

Browse to

Scroll down to the map, navigate to your location, and click on one of the circles (each circle represents a single refinery). The darker the circle the higher the benzene output. Screenshot of EPA map of refineries in the United States

After selecting a single plant, you can view the detected level of benzene at each fence line monitoring location.
Screenshot of EPA map of fence line monitoring stations at a refinery owned by Shell

There’s also a table that shows compliance and average emissions per month. Screenshot of average benzene output at a refinery owned by Shell

If you are concerned about potential benzene exposure, 4U Health’s Environmental Toxins Test quantifies the amount of benzene and 13 other potentially harmful pollutants in your urine. It’s available without a doctor’s order, includes all of the supplies required for at-home collection, and a prepaid mailing label to send your sample back to the lab. If you have any questions about this or other tests please reach out to us at

At Home Environmental Pollutants Test – Includes Benzene, Parabens, MTBE, & More

Measures 14 metabolites that can help define an individual’s toxic burden and provide valuable information for a targeted nutritional and detoxification intervention.


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Navigating the murky waters of legal marijuana and pre-employment drug screening

Marijuana Leaf Balls and Vape Pen

Marijuana Leaf Balls and Vape Pen

As of April 2023, forty states have legalized medical and/or recreational marijuana despite the federal government’s continued designation of cannabis as a Schedule 1 substance. In most of the country, employers can still require testing for THC as a condition of employment.<sup>1</sup>

For example, in California, where recreational marijuana is legal for adults, employers are still permitted to conduct pre-employment drug screenings and terminate employees who test positive for THC, as long as the testing complies with state laws and regulations.2 Similarly, in Colorado, one of the first states to legalize recreational marijuana, employers can still enforce drug-free workplace policies and require drug testing as a condition of employment.3

As of April 2023, forty states have legalized medical and/or recreational marijuana despite the federal

The Department of Transportation (DOT) regulates drug testing for employees in safety-sensitive positions such as commercial drivers, pilots, and railroad operators. DOT drug testing requirements include pre-employment testing, random testing, reasonable suspicion testing, post-accident testing, and follow-up testing. Marijuana is one of the five drugs in the DOT screen; the others are cocaine, opiates, amphetamines, and phencyclidine (PCP).

The detection window for THC (tetrahydrocannabinol) in urine & saliva can vary depending on several factors, including the frequency and amount of use, individual metabolism, and the sensitivity of the drug test. According to a review of studies published in the journal “Forensic Science International,” chronic users of cannabis may test positive for THC in urine for up to 30 days after last use, while occasional users may test positive for up to 10 days.4 However, it’s worth noting that some people may test positive for longer periods, especially those who use high doses or have a slower metabolism.5
If you are worried about passing a looming drug test, you can pre-test with 4U Health’s Urine and Saliva Drug Tests. We use the same sensitive and accurate technology as employer and DOT-mandated screening. We’ll ship you a kit with everything you need to collect a sample. Mail it back to the lab with a pre-paid shipping label and within 48 hours you will know if you are ready to test for employment.

1National Conference of State Legislatures. (2022). Marijuana Overview
2California NORML. (n.d.). Employment Rights
3Colorado Department of Labor and Employment. (2022). Workplace Drug Testing.
4Huestis, M. A. (2007). Human cannabinoid pharmacokinetics. Chemistry & Biodiversity
5Lowe, R. H. (2021). Cannabis drug testing: Current methods and emerging technologies

At Home Drug Test, Urine (78 Target)

Urine test for the presence and quantity of 31 different classes of drugs present in urine, such as alcohol, amphetamines, cannabis, cocaine, opiates/opioids, MDMA, & more.


At Home Drug Test, Saliva (54 Target)

Saliva test for the presence and quantity of 31 different classes of drugs present in urine, such as alcohol, amphetamines, cannabis, cocaine, opiates/opioids, MDMA, & more.


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