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Post-Accident Drug Testing Laws Overview

When a motor vehicle or workplace accident happens, law enforcement and employers often require post-accident drug testing. This is to determine if drug use contributed to the incident. State laws and federal laws dictate the circumstances under which such testing is permissible. These laws aim to reduce incidents of impairment, particularly under the influence of drugs or alcohol.

Federal Guidelines

The Federal Motor Carrier Safety Administration (FMCSA) and the Department of Transportation (DOT) regulate post-accident drug testing for Commercial Motor Vehicle (CMV) drivers holding a Commercial Driver's License (CDL).

The CFR (Code of Federal Regulations) outlines these requirements. The code typically mandates a drug test within a few hours of the accident. Alcohol testing should be conducted within a two- to four-hour timeframe. Drug tests should happen within 32 hours.

FMCSA Guidelines

According to FMCSA guidelines, post-accident drug testing is mandatory in events involving:

  • Human fatality
  • Bodily injury requiring immediate medical treatment away from the scene
  • Vehicle damage requiring towing

It is critical for the CMV driver to remain available for testing. They should refrain from using alcohol for eight hours following the accident or until the test is performed. The primary reason for this is to ensure that the test results are accurate. The test results should reflect the driver's state at the time of the accident rather than any substance use that occurred afterward.

If a driver were to consume alcohol or drugs after an accident but before a test, it could skew the test results. This would make it difficult to determine whether impairment contributed to the accident. The rule also helps prevent drivers from using post-accident substance use as an excuse for positive test results.

Failure to remain available for testing or consuming alcohol before testing can result in the same penalties as a positive test result.

Penalties include:

  • Being placed out of service
  • Being fined
  • Losing commercial driving privileges

Occupational Safety and Health Administration (OSHA) Guidelines

The Occupational Safety and Health Administration (OSHA) also sets guidelines for drug testing policies in the workplace. They caution against indiscriminate post-accident drug testing, suggesting that such practices could discourage reporting of workplace injuries.

OSHA recommends testing only when there is a reasonable suspicion that drug use caused a work-related injury or workplace accident. They also encourage employers to include drug screening as part of their return-to-duty process following a workers' compensation claim.

Reasonable suspicion refers to a belief based on articulable facts and reasonable inferences drawn from those facts that an employee is under the influence of drugs or alcohol.

Reasonable suspicion might be drawn from things like:

  • Direct observation of drug use
  • Abnormal conduct while at work or a significant deterioration in work performance
  • Evidence of drug use or possession of drugs or drug paraphernalia in the workplace
  • Information provided either by reliable and credible sources or independently corroborated
  • Evidence that the employee has tampered with a drug test

Reasonable suspicion generally requires more than a guess or a hunch. The employer should be able to articulate why their suspicion is reasonable.

Testing Procedures

Standard post-accident drug testing often includes:

Drug tests generally screen for marijuana, cocaine, opioids, amphetamines, and PCP. Positive test results could affect:

  • A CDL driver's ability to maintain their license
  • An employee's job status
  • The outcome of a workers' compensation case

CDL Driver

CDL drivers are subject to strict drug and alcohol testing requirements. This is due to the nature of their work. Safety is key when operating large, dangerous vehicles.

If a CDL driver tests positive for drugs or alcohol, it can result in immediate suspension or revocation of their license. Additionally, they might be required to complete a return-to-duty process. This often includes substance abuse counseling or treatment. They must complete this before they can operate a commercial motor vehicle again. A positive test could also impact their future employment prospects.


In a workplace setting, an employee who tests positive for drug use might face disciplinary action. This could include termination.

The specifics can depend on the employer's policies and the nature of the job. For example, a position that requires operating heavy machinery or driving might have zero tolerance for drug use. Additionally, a positive test could affect an employee's eligibility for promotions. In some cases, an employee might be required to complete a drug rehabilitation program as a condition of continued employment.

Workers' Compensation Law Case

If an employee is injured at work and files a workers' compensation claim, a positive drug test can complicate matters. In many states, workers' compensation laws allow for a reduction or denial of benefits if the employee's injury is found to have been caused by drug or alcohol impairment. If the drug test shows that the worker was under the influence at the time of the accident, it could be argued that the worker's impairment contributed to the injury, leading to a denial of the claim.

State Laws

While federal guidelines provide a broad framework, state laws vary. Some states have strict testing requirements, particularly for car accidents leading to bodily injury or fatalities. Other states have more relaxed rules.

Here are some examples:


The state of California does not require mandatory post-accident drug testing after a motor vehicle accident. However, law enforcement may request a blood or breathalyzer test if they suspect a driver is under the influence of drugs or alcohol. 

In the workplace, employers generally have the discretion to implement drug testing policies. This means the employer must believe the employee caused or contributed to the accident. However, the employer must not violate the employees' right to privacy.


Texas has more specific requirements in relation to truck drivers. A commercial motor vehicle driver who is involved in an accident that results in severe injury or human fatality and a truck driver who receives a citation from either state or local law for a moving traffic violation must be drug tested if the accident involved:

  • Bodily injury to any person who received immediate medical treatment away from the scene
  • Disabling damage to one or more vehicles involved, and the vehicle had to be removed by a tow truck or another vehicle

This timeframe is typically within hours of the accident. Specifically, alcohol tests must be completed within eight hours, and drug tests must be completed within 32 hours of the accident. Texas workers' compensation law includes a provision where benefits can be denied if the injury is determined to be the result of the employee's drug or alcohol use.

New York

New York law does not mandate post-accident drug testing for typical car accidents. Still, law enforcement may require a test if they suspect impairment. For workplace accidents, New York law permits drug testing under certain circumstances.

These include:

  • When there's reasonable suspicion of drug use
  • After workplace accidents
  • As part of a return-to-duty process


Ohio requires mandatory drug and alcohol testing for commercial motor vehicle drivers in certain circumstances:

  • If they are involved in a fatal accident
  • Any accident in which the driver is cited for a moving violation prior to the accident and immediate medical treatment away from the scene is required for bodily injury to any person
  • If the wreck was serious enough to render a vehicle disabled, thus requiring it to be towed, and the commercial vehicle driver received a citation at the scene

In workplace injury cases, an injured worker's compensation may be denied if the injury was caused by being under the influence of drugs or alcohol.


Below, we have covered a few frequently asked questions about post-accident drug testing.

Can I Refuse a Post-Accident Drug Test?

You can refuse a post-accident drug test, but this refusal can have serious repercussions. In the case of a commercial motor vehicle driver, refusal to submit to a drug or alcohol test is seen as equal to testing positive, according to FMCSA regulations. This could lead to immediate removal from safety-sensitive functions and even job termination. For employees in other sectors, refusing might be grounds for termination, depending on company policies and state laws.

What Happens if I Test Positive?

For truck drivers, a positive test could result in removal from duty. It could also result in undergoing a return-to-duty process under a substance abuse professional's supervision. Other employees might face disciplinary actions, up to and including termination. From a legal perspective, a positive result could be used as evidence in a court case. This could lead to liability in an accident or denial of a workers' compensation claim.

Are Pre-Employment and Random Drug Tests Required?

The requirement for pre-employment and random drug tests varies based on:

  • Specific state laws
  • Federal regulations applicable to certain industries
  • Company policy

Under FMCSA and DOT regulations, pre-employment drug testing is required for truck drivers and other safety-sensitive positions. Random drug tests are also part of these regulations. In other industries, while such tests are permissible, they are not always mandatory. They must follow specific guidelines to ensure they do not infringe upon workers' rights.

Connect With a Lawyer Today

Understanding post-accident drug testing laws is essential. This is especially true if you are an employer or an employee in a safety-sensitive industry. If you need legal advice on this topic, reach out to an employment lawyer. They can provide up-to-date knowledge and guide you through state and federal laws related to drug testing.

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