Drug Testing

Does Your Co-op Drug Test?

Yes, many co-ops do require a drug test. Big companies are more likely to drug test than small companies, but some small companies drug test too. Check the company’s Human Resources website for policies on drug testing.

Drug Testing Policies

There are several types of drug tests that an employer can ask you to take. Sometimes, a drug test is required before getting hired. Additionally, drug testing can be requested during your employment period. It is important that you read and understand the human resource policies at your company so that you know what might be expected of you in regards to drug testing. Listed below are the common reasons for drug testing.

PRE-EMPLOYMENT TESTING – This type of drug testing is conducted to prevent the hiring of individuals who use drugs. Typically a candidate for a job is required to provide a specimen during the job application process. Generally, a negative drug test result is required before an employer will make a job offer to the applicant. If you know you really want a job, you should make sure that you are prepared to pass this kind of a drug test.

RANDOM DRUG TESTING – Random drug testing is a strong deterrent to drug users because it is conducted unannounced. Using a random selection process, the employer selects one or more individuals from all of the employees included in the employer’s workplace drug testing program. Federally mandated safety-sensitive workers- which include pilots, bus drivers, train operators, truck drivers and workers in nuclear power plants are required to undergo random drug testing as mandated by the U.S. Department of Transportation and the Nuclear Regulatory Commission.

PERIODIC – Periodic testing is usually scheduled in advance and is uniformly administered to all employees. Employees are generally informed ahead of time so that they know the date that their specimen will be collected.

REASONABLE SUSPICION – Reasonable suspicion drug tests, sometimes called “probable cause tests” are conducted when supervisors have concerns or evidence of drug abuse in the workplace. These types of tests are requested when an employer has witnessed the possession or use of drugs while at work, or if the employee is suspected to be under the influence while on the job. Typically, an employee would need to prove that they were drug-free to maintain their employment.

What kind of sample will you be asked to provide?

There are several ways to test whether or not there are drugs in your system. The most common method of determining that an employee is drug free is to ask them to visit a medical facility or lab and provide a sample for testing. The four most popular drug tests are urine test, saliva test, hair test, and blood test. By analyzing your body fluid, the presence or absence of drugs can be determined.

  • URINE TEST – Urine testing is the most common testing method. It detects recent or new drug use and can reveal the presence of drugs going as far back as 90 days for the heaviest drug users. Urine testing can be used to detect a wide variety of illicit and prescription drug use. It is currently the only approved modality of testing for federal safety-sensitive workers who are mandated to undergo drug testing. Typically tests are administered under the supervision of a test administrator to reduce the risk of sample tampering.
  • SALIVA TEST – Saliva testing, also called oral fluid drug testing, is the second most utilized screening method. It is best for detecting more recent drug use only. Employers typically collect an oral fluid specimen under the direct observation of the test administrator.
  • HAIR TESTING  Hair testing is gaining broader appeal because it provides a longer window of detection, revealing drug use going back as far as 90 days for virtually all illicit drugs, regardless of the amount consumed. Hair testing is also very reliable because a sample of hair is removed from the individuals head by a test administrator making it virtually impossible to tamper with the sample.
  • BLOOD TESTING  Blood testing is the least popular method of testing because it does not offer a long range detection window. Almost all drugs are no longer present in an individual’s blood stream after a couple of days making it easier to pass a blood test simply by abstaining from drug use for a few days when you are going to be tested. In addition blood testing is considered more intrusive given that a needle needs to be injected into the donors vein to obtain a sample. In addition, blood tests tend to be more expensive than the alternate methods, so fewer employers rely on them for drug screening because it is costly.

How Long Will Drugs Show Up on a Drug Test?

The amount of time that drugs stay in your system can depend on how much you are using the drug. If you are taking a urine or saliva test, the drug will appear in your sample for a longer period of time if you are a daily drug user. If you are an infrequent drug user, the drug will likely not stay in your system as long. The chart below shows the duration of time that various drug tests can reveal your drug use. In some cases a range of time is provided. If you are a heavy drug user, the drugs will likely stay in your system for the longest period of time. If you are concerned about passing a drug test, you should always allow yourself the maximum amount of time to ensure that the drug is no longer present in your body.


Urine Test

Saliva Test

Hair Test

Blood Test


12 Hours

1-5 Days

90 Days

12 Hours


30-90 Days

10 Days

90 Days

2 Days



2-5 Days

2-5 Days

90 Days

24 Hours


3-4 Days

1-4 Days

90 Days

24 Hours


10-30 Days

1-10 Days

90 Days

24 Hours


24 Hours

1-2 Days

90 Days

12 Hours

Myths vs. Truths About Passing a Drug Test

Myth: You can drink or eat something that will “cleanse” your body, resulting in a negative drug test.

Truth: While there are many commercial products available that claim to do this, and many urban myths about household products that will cleanse your system, the truth is that none of them works. Here are a number of products people have tried – none of which work.

  • B Vitamins and Niacin – These products turn urine yellow. Before creatinine testing became standard, basic specimen validity testing was based, in part, on the color of the specimen. Since clear specimens were not accepted, this was a useful method of avoiding detection when submitting a diluted specimen. Creatinine testing is a much better indicator of urine concentration and authenticity than color alone. Taking vitamins and niacin will not cover up the presence of drugs in your urine sample.
  • Pectin – Eating pectin does not help you pass a drug test. What pectin DOES do is act as a preservative and gelling agent in jams, jellies, pie fillings and some milk drinks. In addition, it is used to add dietary fiber to many of the foods we eat.
  • Herbal Teas – Herbal teas may have various beneficial effects, but passing your drug test is not one of them. Consumed in sufficient quantity, tea may make urine dilute as it is a diuretic, but there has been no evidence to show that tea has any ability to change the results of a drug test.
  • Vinegar – Enough vinegar will cause a pretty good case of heartburn, but will not clean your urine.
  • Herbs and Herbal Supplements – The ever-popular "Golden Seal" falls under this category, but much like herbal teas, there is no evidence what so ever to support claims that ANY herb can cleanse urine of drugs.
  • Energy Drinks – No amount of energy drink consumption will cause a false negative (or positive) test result due to the ingredients in the drink. Drinking several of them, of course, can cause urine to be diluted.
  • Chemical Cleaners – Drinking chemicals such as bleach and Drano will do nothing to eliminate drugs from your system. Instead, they may cause esophageal burning, vomiting, all sorts of digestive problems and maybe even death! This is extremely dangerous. Do not consume chemicals like bleach or Drano. 
  • Drinking Lots of Water- Consuming large quantities, about 1 liter, of any liquid will significantly dilute the specimen within 30 minutes to 1 hour of consumption. This is the reason that all specimens tested should have a Creatinine level determined to evaluate whether the sample is too dilute to provide a valid test result. If you drink too much water in an effort to hide drugs from appearing in your urine, it is likely that you will be asked to re test.
  • “Pass Your Drug Test” Drinks – Some people pay $50+ for these drinks that claim to clean urine. In reality, these drinks don’t do not do anything other than add suspicious and unnatural chemicals to your urine sample. These chemicals are picked up on immediately by all professional lab services, as they are known as a common methods for attempting to cover up drug use. If your urine specimen has unnatural chemicals, you will likely be asked to resubmit a new sample. You will not pass your test by taking these scam products.

To reiterate, a donor may be able to dilute their specimen, but there is nothing that can be consumed that will “fool” a drug test or “cleanse” the urine.

Myth: Antibiotics will not cause a false positive drug test.

Truth: There is a class of antibiotics that may cross react with the opiate screen and may alter the result. If you are taking any antibiotics, you may want to list them on your drug testing paperwork, or ask the test administrator.

Myth: Eating poppy seeds can cause you to have a positive test result for opiates.

Truth: You would have to eat an exorbitant amount of poppy seeds for it to impact the results of your drug test. In addition, the poppy seeds would need to be un-washed, and most commercial bakeries only use washed poppy seeds. It is extremely unlikely that eating baked goods with poppy seeds would cause any sort of change in your drug test.

Myth: Exposure to second hand marijuana smoke can yield a positive test result.

Truth: Passive exposure to a drug can make it appear in your urine, but actual consumption of the drug makes it appear at a much higher concentration. To avoid the argument that a positive result is due to passive contact, cut-off levels have been established. These cut-off levels are set to make it virtually impossible for a specimen to screen positive from passive contact.


National Council on Alcoholism and Drug Dependence  - provides education, information, help, and hope to the public. It advocates prevention, intervention, and treatment through a nationwide network.

Massachusetts Substance Abuse Information and Education - Find a treatment center, learn how to get help and information for family and friends.

Drug Screening - Wondering if you have a drug problem?  This screening will provide feedback about your use.

e-TOKE - Curious about your marijuana use? Get feedback from this quick assessment.