Julius R. Petri (1852-1921), a German bacteriologist, invented the first petri dish. He used this shallow, circular glass dish with a loose-fitting cover to culture bacteria and other microorganisms. Then, in the mid 1960’s injection molding technology sufficiently developed so that petri dishes could be manufactured out of clear polystyrene plastic. These dishes were merely clones of the first, glass petri dish. They were large, heavy and over-constructed. In fact, they were almost twice the weight of most conventional plastic petri dishes manufactured today.

The first plastic dishes were inexpensive as crude oil and its by-products were cheap commodities. However, in the mid-1970's, the Organization of Petroleum Exporting Countries (OPEC) took advantage of shifting market conditions, and the geopolitical and economic disruptions in the Middle East which caused the price of petroleum-based products to skyrocket.

As the supply of polystyrene became restricted, the price started to soar; as a result, the cost of plastic petri dishes also escalated. Customer-pressure then forced petri dish manufacturers to cut back on the excess size and weight of the petri dishes to reduce cost. The 25-gram "DINOSAUR" petri dishes became extinct.

In the mid-80’s, further development in raw material and a better understanding of the injection molding process, allowed most manufacturers to reduce the weight of their petri dishes to the 15 to 17 grams range. This new petri dish remained unchanged and became an industry standard for almost 7 years without any advances or innovation. Since that time, every company merely copied other companies until the early 1990’s, when Phoenix Biomedical developed, perfected, and patented the STAR™DISH concept.

Phoenix Biomedical Products Inc., a Mississauga-based, Canadian company, has manufactured polystyrene petri dishes used for diagnostic testing in medical, industrial and research laboratories since 1980.

In its attempts to find a solution to the increasing cost of plastic and the environmental concern with regards to the disposal of medical waste, Phoenix Biomedical’s team of engineers and researchers has developed a new generation of petri dishes. The STAR™DISH is manufactured with 30% less plastic, thus helping to preserve our valuable, non-renewable resources by significantly reducing medical laboratory waste.

The STAR™DISH series not only reduces the amount of plastic required to manufacture the product but is also of higher quality, ensuring consistent test results.

The innovative design of the STAR™DISH incorporates transparent ribs moulded in the dish. These ribs reinforce the dishes, making them stronger and less brittle than conventionally designed dishes. The ribs also act as a stiffener to keep the bottom from warping, as flatness is very important.

A method known as "centre-gating" is used in manufacturing the STAR™DISH. In this process, the plastic enters the mould cavities from the centre of the dish, runs rapidly through the "ribs" that act as flow leaders, and then flows in a cobweb pattern, thus substantially reducing plastic stress during the filling of the cavity. This patented unique process, “the combination of centre-gating and low-profile ribs,” makes a resilient, flatter petri dish and allows us to substantially reduce the weight without sacrificing quality.

Phoenix Biomedical has manufactured over one billion of the environmentally-friendly STAR™DISH in its “class 10-100” clean rooms, sold in 50 countries.

The STAR™DISH makes an important contribution in support of strategies to reduce medical plastic waste that is burdening our global environment.

Given the current global size of the petri dish market, this product can help control diagnostic testing costs and reduce the amount of plastic entering our waste system by up to 80 million kilograms annually.