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October 10, 2016

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How much THC does it take to be impaired? Medical Marijuana and its' EffectsTHC-impaired drivers have long been a concern for road safety officials. While alcohol is the most commonly used drug in Driving Under the Influence (DUI) cases, THC, the psychoactive component of cannabis, is not far behind.

So, how much THC does it take to be impaired? The dangers of driving while impaired by drugs are well documented.

Road crashes are the leading cause of death among young people aged 16-29; drug-impaired driving accounts for about 18% of these crashes.

In the United States, marijuana is the most commonly detected drug in drivers involved in fatal crashes. It has been estimated that around 6% of weekend drivers are positive for THC.

Were you severely injured or lost a loved one in an accident caused by a THC-impaired driver? The personal injury attorneys at Rosenfeld Injury Lawyers, LLC provide legal representation for victims harmed by marijuana-impaired driving.

Call our THC accident lawyers at (888) 424-5757 (toll-free phone number) or use the contact form today for immediate legal advice and schedule a free consultation.

All confidential or sensitive information you share with our legal team remains private through an attorney-client relationship.

What is THC?

Tetrahydrocannabinol (THC) is a chemical responsible for producing most of the psychological effects of smoking and consuming marijuana.

The chemical effects of cannabinoid receptors are concentrated in specific areas of the brain that are known to affect memory, thinking, coordination, pleasure, and time perception.

While the human body naturally makes cannabinoid chemicals, the compound THC can also be consumed or inhaled from the resin in the glands of marijuana plants.

The chemical stimulates brain cells to release dopamine, creating euphoria and other side effects.

Why Marijuana Impairment Remains the Leading Drugged Driving Offense

Several factors contribute to recreational marijuana use leading to crashes who tested positive for marijuana. When drivers use marijuana for any reason, the effects take hold immediately.

First, THC impairs psychomotor skills such as reaction time, hand-eye coordination, and vigilance leading to slower decision-making and driving mistakes.

According to the Governors Highway Safety Association, THC can affect judgment and decision-making, leading to risks such as engaging in other dangerous driving activities (such as texting or using a cell phone).

Finally, THC can increase anxiety and arousal levels, leading to more risky behavior, including drugged driving beyond the legal limit.

As medical and recreational marijuana continues to be legalized throughout the United States, it has proven important to lawmakers and police officers to find a way to measure a driver’s impairment with THC (tetrahydrocannabinol) in their system.

The main issue with finding a standardizing level of THC impairments is that THC is not processed similarly to alcohol blood level.

While the legal limit for alcohol is easy to measure at 0.08 using proven devices, it is difficult for a law enforcement officer to determine a driver’s blood THC concentrations that encompass its effects differently for everyone who uses it for medical or recreational use.

Testing for Marijuana Impairment is Not Yet an Exact Science

There is still debate among experts over whether marijuana is impairing drivers. Some say yes, others no of per se limits to detect cannabis-related driving impairment.

Even so, many jurisdictions use per se limits to determine impairment of medical or recreational marijuana and identify THC concentrations to follow zero-tolerance laws.

Accurately identifying the suspect’s THC concentration identifying drug impairment is like alcohol testing, which uses machinery to identify accurate blood levels at a rate measured by nanograms per milliliter.

The National Highway Traffic Safety Administration (NHTSA) says urine tests are unreliable in accurately identifying THC concentrations.

They detect THC levels using saliva, hair, sweat, breath, and blood tests. However, according to the agency, “Urine samples cannot reliably indicate recent use of marijuana.”

Unlike alcohol, the THC level remains in the fat deposits after cannabis use. So even if someone doesn’t smoke marijuana within the last few hours, they could potentially be tested positive for THC.

The Correlation Between THC and Car Accidents

More research needs to be done. In February 2018, a highway safety study found that marijuana use correlated with an increased risk of fatal crashes.

However, it wasn’t clear whether the correlation was due to marijuana with active THC itself or other factors such as age, gender, race, education level, or socioeconomic status.

The Insurance Institute of Highly Safety concluded that “more studies are needed to better understand the relationship between marijuana use and traffic safety.”

A 2016 review of scientific evidence gathered since 2000 showed that most studies found increased drivers’ erratic driving behavior and involvement in car crashes who tested positive for marijuana use.

For example, one study found that crashes involving drivers who tested positive for THC increased by 50 percent compared to those who didn’t use legal or illegal drugs.

Another study found that having five drinks per day was associated with a 30 percent increase in crash risk compared to abstaining from drinking.

Marijuana Affecting Driving Performance

In addition to the studies mentioned above, several researchers have examined the effects of marijuana on driving skills.

One study found that, like drunken driving behavior, subjects with an average THC limit performed worse on cognitive tasks like memory, attention, reaction time, and working memory after smoking marijuana.

Another study found that people had slower reaction times and poorer accuracy when performing visual searches after smoking marijuana.

Yet another study found that marijuana users took longer to complete simple motor tasks.

What happens when you test positive for THC? There is a zero-tolerance policy for driving impaired, and you’ll likely receive a citation.

Depending on your location, you might face fines ranging from $100-$500. Chronic users might lose their driver’s license if they receive multiple citations.

Different Forms of Cannabis Extracts, Edibles, and Topicals

Health Canada recently announced it would allow cannabis companies to sell cannabis-infused foods, drinks, and cosmetics. The new law will enable edibles, extracts, and tinctures.

But there are some rules you need to know before stocking up on marijuana.

These marijuana regulations include:

  • Products cannot contain more than 10 ng/ml of THC.
  • Users can only purchase products online.
  • Only adults aged 19 and older can buy them.
  • The drugs must be stored out of children’s reach.
  • Labels must include clear instructions on how to consume them safely

The government says it will monitor the market closely and keep track of consumer safety issues.

Smoked/Inhaled Cannabis vs. Edible Cannabis

Edible cannabis products are typically consumed by mouth or as oral fluid, whereas smoked/inhaled products are often taken via inhalation.

This difference makes it necessary to know how much THC you’re consuming.

If you’re unsure about what dose you’re taking, start with marijuana products that have low doses.

Products containing 2 mg or less of THC per serving should relieve adequately.

Cannabis Extracts Used for Vaping

Cannabis extracts are usually smoked, not vaporized. Marijuana concentrates contain high levels of THC, the psychoactive ingredient in marijuana, which makes it easier to feel the effects of the drug.

However, it also requires inhaling more smoke into the lungs.

Smoking cannabis extracts is typically less safe than vaping because it exposes the smoker to more tar and carcinogens. But the benefits of vaping over smoking might outweigh the risks.

Vaping is safer than smoking. No combustion products, like carbon monoxide, and the aerosol produced contains fewer toxins than cigarette smoke.

However, vaping does expose people to some chemicals found in tobacco known to cause cancer, including:

  • Nicotine
  • Acetaldehyde
  • Formaldehyde
  • Acrolein
  • Crotonaldehyde
  • Benzene
  • Ammonia
  • Hydrogen cyanide
  • Hydrogen chloride
  • Fluoride
  • Hydrogen sulfide
  • Nitrogen oxides
  • Nitric oxide
  • Phenols
  • Propylene glycol
  • Pyrolysis compounds
  • Sulfur dioxide
  • Tars

Combining alcohol use with cannabis use increases the risks associated with both substances, according to the National Institute on Alcohol Abuse and Alcoholism.

The risks include increased impairment and chances of a fatal crash.

People who consume cannabis while drinking alcohol are likelier to experience drowsiness, dizziness, impaired coordination, slower reaction times, lower blood pressure, and difficulty thinking clearly.

The Effects of THC-Cannabis Edibles, THC Oils, and Extracts on Driving Ability

An edible cannabis product and oral fluid can impair judgment, motor skills, reactions, and other cognitive functions similar to those caused by smoking cannabis, including impairments of perception, attention, memory, reasoning, problem-solving, decision-making, and reaction times.

These effects are most pronounced 30 minutes after consumption, although some people report feeling the effects immediately.

Driving while impaired by any substance is illegal. However, it is essential to note that cannabis does not make you immune to being pulled over by police.

If you plan to use cannabis-infused foods or drinks while driving, do not consume anything within two hours before driving.

You must wait at least 2 hours before getting behind the wheel again. Talk to your doctor if you are concerned about how cannabis might impact your driving abilities.

Your physician can help determine whether you are fit to drive safely.

The Risks of Driving after Consuming Edible Cannabis

Driving while under the influence of marijuana can be dangerous. Edibles take longer to kick into effect, making people think they are safe to operate vehicles.

But one thing that makes driving while high different from drinking alcohol — you cannot legally consume cannabis and still drive.

Driving while impaired by cannabis is against the law whether you smoke, eat or drink, vape, or even swallow.

Cannabis affects everyone differently. Some feel fine after consuming it; others do not.

And because there is no safe level of THC in blood, drivers should never assume they can drive after eating or smoking cannabis.

How Long to Wait to Drive after Consuming Edible Cannabis

Cannabis edibles are often consumed slowly over several hours while smoking cannabis causes immediate intoxication. However, no set waiting time is required before driving after ingesting either product.

A study by researchers at the University of British Columbia found that drivers who had ingested cannabis three hours before driving did not show signs of impairment.

Drivers who had smoked cannabis showed signs of impairment within one hour of consumption.

The findings suggest that people who consume cannabis products should wait at least three hours before driving because THC levels take about one hour to reach peak concentrations in the blood.

If someone consumes cannabis within three hours prior, their THC levels will still be low enough to avoid causing impairment.

How Police Test for Edible Cannabis in Drivers

Police officers can now use oral fluid drug screening equipment to detect whether someone has consumed marijuana.

This technology allows officers to determine whether a driver has ingested cannabis, even if it hasn’t been detected in blood samples taken from the person.

The SFST is one of several field sobriety tests police use. These standard tests involve walking heel to heel, counting backward, reciting the alphabet, and others.

They’re designed to help officers identify signs of impairment, such as slurred speech, staggering gait, and lack of coordination.

Oral fluid drug testing equipment works similarly to breathalyzers, except it collects saliva rather than air. Saliva contains many components that can indicate recent consumption of drugs.

Blood samples are another way for police to screen people suspected of impaired driving. A blood sample is collected via finger prick and sent to a lab for analysis.

Cannabis Legislation Changes the Workplace

Cannabis legalization in Canada has been associated with a rise in traffic accidents involving drivers with THC levels over the national legal limit.

But a recent study suggests it might be because people aren’t driving while impaired anymore.

Even though drivers are not intoxicated — they’re just high — they could still be affected by other factors like fatigue or stress.

And no standard test exists for how much THC is present in a person’s bloodstream.

A study found that drivers who tested positive for THC had lower accident rates than those who tested negative.

Researchers believe this is because the former group took breaks during work shifts and drove slower.

But even though drivers are not intoxicated, they should not drive if they are feeling any effects of cannabis.

They should immediately pull off the road and call a cab, even though THC levels drop rapidly.

Cutoff THC Levels Make Measuring a Legal Limit for Impaired Driving Challenging

There is no clear definition of what THC level causes drivers to be considered impaired. This makes it hard to enforce laws against driving under the influence of marijuana.

A study published Monday in JAMA Internal Medicine found that the current legal thresholds are arbitrary and vary depending on where you live.

The researchers analyzed data from over 15,000 National Survey on Drug Use and Health participants, including those who reported having driven within the previous month.

They used self-reported information about THC levels in blood drawn during the survey.

They found that the median THC concentration in the blood samples was 0.05 ng/ml. At this level, just one out of every 20 drivers tested would fail a standard field sobriety test.

However, the researchers found a significant difference in the number of drivers who failed tests depending on whether they lived in a state with a lower or higher cutoff.

Hire Personal Injury Attorneys to Resolve your Marijuana-Impaired Driving Compensation Claim

Were you severely injured, or did a loved one lose their life in a marijuana-impaired driving accident?

The car accident injury attorneys at Rosenfeld Injury Lawyers, LLC can evaluate your claim and review a blood test to determine the impairing substance that led to your injurious or fatal crash.

Contact us at (888) 424-5757 (toll-free phone number) or use the contact form to schedule a free consultation.

We accept all cases on a contingency fee agreement, meaning you will pay no upfront fees until we resolve your case through a negotiated settlement or jury award.


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