415 4th Street,
Oakland, CA 94607

(510) 625-7877 (patients or general inquiries)

(510) 681-4873 (vendors)

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Purple Heart Patient Center

Clean Cannabis Program

How Do We Compare?
We may be the safest and healthiest dispensary in Oakland and the East Bay.

Few labs or dispensaries in the Bay Area test for all three criteria:  bacteria, mold/yeast, and pesticides.  Most dispensaries that require safety testing only test for mold/yeast and possibly pesticides, but Purple Heart Patient Center is one of the few dispensaries that tests for bacteria.    

Not only do we require more tests before we deem a product safe for our patients, we also chose the lab that would help us implement the most stringent safety guidelines In the absence of industry wide standards, each dispensary decides for themselves which guidelines are appropriate for their patients.

AOAC and Purple Heart Patient Center guidelines:  Purple Heart Patient Center uses the same acceptable limits for APC, Mold, Yeast, Coliform, E. coli, and Pseudomonas that the FDA requires for raw food.  These are the only standards that ensure safety for patients with AIDS, Leukemia, or any other immune compromising disease.  While most flowers pass our mold/yeast and pesticide test, we turn away medicine every week for failing our APC limits on aerobic bacteria.  Most, if not all, of the flowers rejected by Purple Heart Patient Center could easily pass safety-testing standards of other dispensaries.  The flowers that fail our APC testing are extremely dangerous to patients with compromised immune systems.  While mostly harmless to healthy individuals, if bacteria on those flowers are breathed in by those with weak immune systems, the elderly, or those who have been hospitalized for long periods of time it could cause the patient to develop an infection.  Those with cystic fibrosis, AIDS those who have undergone chemotherapy, or are otherwise immunocompromised are at risk for developing bacterial infections. The bacteria can be inhaled and infections can become especially deadly when present in the lungs or bloodstream.

American Herbal Products Association Guidelines:  Some labs and dispensaries use the AHPA guidelines.  These guidelines allow 100,000 CFU/G of Mold – this is ten times more mold than we allow. The AHPA guidelines allow 10,000,000 CFU/G of Aerobic Bacteria, 100 times more bacteria than we allow.  Even if medicine passes the AHPA guidelines, it is still not clean enough for use by patients with AIDS, Leukemia, or any other immune compromising disease.


Continue reading for details of all our testing protocols:

All medicine at Purple Heart Patient Center are sent out to a third party lab and have passed the following tests:

Microbiological Testing:

·Bacterial testing (Aerobic Plate Count, APC)- This is a general test to survey the general numbers of bacteria present on a given sample. Aerobic bacteria are a general class of organisms that use atmospheric oxygen and are considered ubiquitous contaminants. In most cases, this is the only bacteriological test needed. Under normal hygienic conditions low colony numbers are recorded. In the event of a positive (large numbers of bacterial colonies being present) test, subsequent specific tests for coliforms, and E. coli would be recommended. Keeping our cannabis free of bacteria is extremely important, as inhaling these bacterium is dangerous for immunocompromised patients.

·Coliforms- Generally speaking, the spore-forming bacteria fall into the coliform bacteria group. These spore-forming bacteria are used as indicator organisms for poor hygiene conditions as they are commonly found in the gut of animals.

·E. Coli- This test, specific for Escherichia coli, is only performed following high APC counts and is indicative of human and animal waste.

·Pseudomonas - This test is only performed following high APC counts. Pseudomonas is a highly dangerous type of antibiotic resistant bacteria.

·Yeast/Mold - This is a very general test for the presence of a number of yeast and fungal species. This test provides a medium specific for variety yeast and fungal species and serves as an indicator based on total number growing colonies recorded. Under normal hygienic conditions low colony numbers are recorded. Since fungal species are somewhat more common on Cannabis flowers and some of them can be pathogenic to humans causing aspergillosis and other lung diseases, this test provides an important safeguard prior to patient consumption.

 Acceptable Limits:

All medicine must meet the acceptable standards set by the AOAC (International Association of Analytical Communities) for bacteria, yeast and mold. The FDA also uses the AOAC standards.

Screening Acceptable Limit
Aerobic Bacteria (APC)
Mold and Yeast Count
Coliform Count 
E. Coli Count
Pseudomonas Count 

Chemical Residue (Pesticide) Testing:

Insects and other pests are common in both indoor and outdoor cannabis cultivations. If left unchecked, these pests can infest and destroy entire crops, sometimes in a matter of days. As a result, many cultivators use toxic chemical pesticides to avoid potential crop loss. Unfortunately, most of these cultivators are either unaware of, or choose to ignore, the potential environmental and health consequences of their actions.

Chemical pesticides are, by design, highly toxic and persistent. Many kill on contact and remain active for weeks, months, and even years. Human exposure to pesticides may lead to acute health problems, such as abdominal pain, dizziness, headaches, nausea, vomiting, as well as skin and eye problems. Many serious diseases, such as cancer, reproductive dysfunction, and asthma have been linked to pesticide exposure.

Patients deserve to know whether or not the alternative medicines they choose contain harmful pesticide residues. It is bad enough that pesticides are used on many, if not most, of the foods sold at our local grocery stores. Our medicines should be clean!

We currently test for some of the most commonly available pesticides, including pyrethrins and pyrethroids. These are the products that are found on the shelves of your local home and garden store. We also test for some less common but highly toxic pesticides, such as Avid.

We use a combination of enzyme-linked immuno assays and gas chromatography to screen samples for pesticide residues.

All samples are first subjected to three independent enzyme-linked immunosorbent assays to verify the absence or presence of pesticide classes. The three assays screen for organophosphate and carbamate pesticides, pyrethroid pesticides, and avermectins (Avid).

Samples are then analyzed by gas chromatography / mass spectrometry (GC/MS) to verify results and in some cases identify the actual pesticide residue detected by the immuno assays. Our GC/MS is calibrated regularly using known standards to ensure the accuracy of our test results.


Residual Solvent Testing

We test all of our concentrates (Oils, Hash, Kief, Vapor Products, etc.) to ensure they do not contain trace amounts of residual solvents.  Solvents like butane, alcohol, and hexane are used to extract the active ingredients of cannabis to make wax and oils. These solvents must completely evaporate from the concentrate before patients can safely use them. 

Every concentrate at PHPC has been sent to a third party lab to be tested for trace amounts of all flammable chemicals such as butane, alcohol, hexane, naphtha and toluene.  PHPC’s acceptable limit for residual solvents is 400 ppm.  Unfortunately, there exists no data looking at the effects (positive or negative) of inhalation of various flammable solvents by smoking cannabis.  The CDC sets a limit of 800 ppm for a safe exposure limit of these chemicals for an 8-hour period. Until toxicologists or medical doctors conduct research on safe limits on inhaling residual solvents in concentrates, we have taken the conservative approach with our detection limit.

Please, consult with your doctor before using concentrates.


Glossary of Microbiological Terms:

CFU - Colony forming units, a measure of the viable bacterial or fungal cells found per gram of sample.  AOAC guidelines dictate this number must fall below a certain threshold to be safe for consumption. 

APC - Aerobic plate count bacteria, an all-encompassing term for bacteria that require oxygen to survive. This test indicates the CFU’s of oxygen consuming bacteria and is used as a screening measure for the general cleanliness of the sample.  High CFU’s (>100,000) found on the APC plate will trigger a Coliform/E. coli test, as it is likely that when there is a high bacterial load, some of the bacteria present may be pathogenic to humans. 

Yeast/Mold - A test to indicate the overall quality of the sample and the fungal load present on the sample. Common forms affecting Cannabis include Botrytis (commonly known as bud rot) and powdery mildew. More than 10 CFU’s of either mold or yeast will cause the sample to fail this test.

Total Coliforms - Total Coliforms include species of bacteria that may inhabit the intestines of warm-blooded animals or occur naturally in soil, vegetation, and water. In water supplies, these bacteria are often associated with disease outbreaks. Although they are not typically pathogenic themselves, their presence indicates the possible presence of pathogens.  More than 100 CFU’s will cause the sample to fail this test.

E. Coli - Escherichia E. coli is a coliform bacterium and is considered an indicator organism of fecal contamination. Some strains are pathogenic to humans.  More than 10 CFU’s will cause the sample to fail this test.

Pseudomonas aeruginosa: This is a robust bacterium that can survive in a variety of environments, such as soil, water and on vegetation. While healthy individuals rarely have problems with Pseudomonas, it is much more dangerous to certain populations, including those who have weak immune systems, the elderly, and those who have been hospitalized for long periods of time. Those with cystic fibrosis, AIDS those who have undergone chemotherapy, or are otherwise immunocompromised are at risk for developing bacterial infections due to Pseudomonas aeruginosa. This bacteria can be inhaled and infections can become especially deadly when present in the lungs or bloodstream.