During National Consumers Week it is appropriate to note that the nation's marketplace operates on the premise that buyers will choose products they consider of good value and safe, and reject those that are not. A problem is that there are hazards that consumers cannot see, but that can be dangerous or even fatal. Some hazards are so hidden even the companies that make the products are unaware of the dangers.

A rubber pacifier on a store shelf seems harmless, but while an infant is sucking on it, cancer-causing nitrosamines could enter the tiny body. Asbestos fibers floating in the air of a school or workplace are visible only through an electron microscope, but the cancer- causing fibers can be inhaled into the body. Formaldehyde, vinyl chloride, benzene and some pesticides also harboed hidden hazards, but fortunately, as a result of government intercession and victims' court suits, some dangers have subsided.

Now comes a study by the Washington-based Media Institute, an organization interested in improving business- media relations, entitled, "Chemical Risks: Fears, Facts and the Media." The theme is that the media are relying too heavily on government warnings and not enough on industry and independent sources. The proof cited is that government sources are quoted more often and at greater length.

Underlying the content analysis approach is the notion that a newspaper or station should present an even-handed report on an issue regardless of what the facts might be. For example, if the subject were drunk driving, a robot-like reporter would quote persons with facts on the hazards of drunk driving and give equal space to those who, perhaps for self-interest reasons, think it's not so bad. If the Media Institute were to analyze the content of actual newspaper articles on drunk driving, it might decide this was unfairly presented too.

In addition to more statements by manufacturers and trade associations, the report urges more use of independent scientists by the media. In fact, in order to make a statement about ethylene dibromide hazards, one of the report's case studies, a scientist would have to study the issue deeply and become expert in it. Acquiring such expertise is time consuming and expensive, and as a result such scientists usually work for either an affected industry or the government.

In the case of EDB, a widely used cancer-causing pesticide found on grain products such as cereals and cake mixes, the government did the analysis of the cancer studies, sampled food supplies, did the chemical analysis and made the risk assessment, all of which led ultimately to action by the Environmental Protection Agency. These were government initiatives and the results probably surprised even thet conscientious manufacturers. The Media Institute report suspects government agencies are self-serving, exaggerate dangers and do not present an unbiased picture.

While commercial interests certainly should have a chance to have their say in the media, I believe most readers look to government to represent the public interest in health and safety. Obviously, I reject the views of the Media Institute report. My concern now is that the media are not reporting adequately the backsliding of health and safety agencies of government.

Take EDB again. In 1975 the National Cancer Institute, after tests with laboratory animals, branded it a carcinogen. Eight years later, prodded by Florida state action, EPA decided strong measures were required. Last spring the head of EPA announced long-term plans to root EDB out from the food chain, but in the interim he recommended tolerance levels he hoped states would adopt and enforce. His goal was "a consistent, coherent approach to what is clearly a national problem."

The result was hodge-podge regulation. EDB is bad for your health, but protection depends on where you live. Some states adopted standards tougher than at the federal level and forced noncomplying products off the shelves. Some adopted lesser standards and some states did absolutely nothing. Manufacturers with national products had to deal with widely varying, state- by-state standards.

Other than a few reports on the confusion in The New York Times and fewer in The Washington Post, where were the press watchdogs -- and the concerned cereal-makers and their industry spokespersons?