Chemical Contaminants in Food

Unintentional Constituents

Food additives are, by definition, added to food intentionally.  All the other chemicals that happen to be there as well are, by definition, unintentional.  These chemicals are generally referred to as contaminants.  There are many different types of molecules in food that are present in food in very tiny amounts.  Some are natural, others are not.  However, to really attract attention as a contaminant, an unintentional chemical constituent of food needs to be implicated. This is pretty much a basic feature of contaminants; no one cares about than unless they are hazardous at least a little bit hazardous.  Demonstrating safety is pretty much out of the question.  A lot of people don’t get that.  So here’s an example:  When Chinese pet food and infant formula producers put melamine into their products in order to fool the test used to determine protein content, they did so intentionally.  That use was also unapproved.  Therefore, as melamine is an illegal food additive, the food is adulterated under FFDCA 409 irrespective of whether or not it is hazardous.  If hazard can be demonstrated, then charges under FFDCA 402 may be brought as well.

The other thing about contaminants that is pretty much true by definition is that they are more difficult to avoid.  Additives can be avoided by simply not adding them.  Sometimes, contaminants get into food by accident, and accidents are at least somewhat avoidable.  Accidently mixing bitter almonds laced with cyanogenic glycosides with regular almonds, for instance.  Those are the relatively easy ones.   But, impossible to avoid is quite common too.  Fish has methylmercury.  Rice has arsenic.  Calcium supplements have lead. Spinach has cadmium.  Corn has fumonisin.  Peanuts have aflatoxin.  French fries and coffee have acrylamide.  Always have, always will.  If you really want to be safe from long-term risks that may happen, just don’t eat.  Don’t breathe either – the oxygen may kill you eventually. The problem with that strategy is, the short-term risks of not eating or not breathing are far greater.   As Hutt (1978) noted nearly 40 years ago: 

Until quite recently, a no-risk food safety policy was widely thought to be an acheivable goal.  To be sure, there was some recognition of potential hazards of the food supply, but they were not the subject of general public knowledge and were thought to be relatively few in number and controllable through appropriate regulatory measures.

In the past two years, however, there has accumulated substantial scientific evidence that carcinogens and other toxic substances pervade the entire food supply.  It is now clear that it is literally impossible to eliminate all carcinogens from food.  Morever, many of the substances whicih pose a potential risk are part of a long-accepted components of food, and any attempt to prohibit their use would raise the most serious questions both of practicality in implementation and of individual free choice in the marketplace.

Being precautionary is tough with contaminants.

Regulation of Contaminants in Food

The introduction of the 1954 Food Additive Amendment dramatically changed the way additives were regulated by the FDA.  It did nothing for the remaining class of chemicals.  Section 406 is just as ineffective as it ever was.  Section 402 must still be applied on a case-by-case basis.  However, even though it is a statute that is over 100 years old, because 402 is still the main legal tool that the FDA can use to regulate contaminants in food it is well worth discussing.   The key clause is 402(a)(1):

If it bears or contains any poisonous or deleterious substance which may render it injurious to health; but in case the substance is not an added substance such food shall not be considered adulterated under this clause if the quantity of such substance in such food does not ordinarily render it injurious to health

This one sentence created two different food safety standards.  The first standard of “may be injurious” applies to chemicals that are “added”.  When this law was first written in 1906, this meant intentional food additives.  But it has since come to be interpreted as any chemical with an anthropogenic (human) origin.  In fact, because the standard is easier to meet, FDA lawyers generally try to argue that everything is added (Hutt et al, 2007).  But, there is no getting around the fact that many potentially chemicals that occur in food have a natural origin.  The standard for those chemicals is “ordinarily injurious”.  The difference between these standards in this:  If a food contains a chemical that causes deleterious effects in some, but not all,  consumers then the food will be meet the “may be injurious” standard, but not the “ordinarily injurious” standard (Hutt et al, 2007). For example, if the peanut allergens that cause adverse effects in a sensitive population occur naturally, then peanuts are not adulterated under 402(a)(1) because the standard is “ordinarily” rather than “may”.

However, when it comes to chemical contaminants (402 can also be used for microbial contamination) there is no denying the fact that 402(a)(1) is rather clunky.  It is designed to regulate food, not chemicals.  The burden of proof is on the government to show harm.  Since it must be applied on a case-by-case basis, it is very difficult to argue that one lot or shipment of food will cause effects from long-term exposure.  So, unless there is a reasonable possibility of clearly observable short-term effects in at least some people, the FDA will probably lose if a case goes to court.

Guidance Values

The main way that the agency influences the food industry is by creation of guidance values.  These include so-called action levels, bottled water quality standards, and a gamut of other values that appear in the FDA Consumer Product Guide (USFDA, 2015), along with some values that are legally enforcable like pesticide tolerances.  The way guidance values really work is this: They represent a promise to the food industry that no action will be taken by the agency as long as the chemical is below the guidance level.  However, it does not mean that the agency will, as is the case with a legally enforceable tolerance, automatically consider a food to be adulterated if the guidance value is exceeded.

There are two reasons guidance values often work well.  The first is that, even though it is a little rusty, when used judiciously 402(a)(1) is a sabre that can be effectively rattled from time-to-time.  No one really wants to go to court over a small shipment of food; not the agency, and not the food industry either. Second, the opinion of the agency is a source of public trust.  It is in the interest of most of the food industry to maintain that trust, because if the FDA says a food is safe, then most people will believe that it is safe enough to eat.  Since guidance values aren’t legally enforceable, setting a level where the main concern is long term exposure is quite possible.  

Toxicology and Contaminants in Food

Compared to food additives, the role of toxicology in the regulation of contaminants is vastly different.  By definition, the food industry has less control  over contaminants additive.  The agency also has less control over the industry.  Then there is the third thing; a toxicologist working on contaminants has very little control over what the agency does.  An agency toxicologist concerned with contaminants functions like an internal consultant.  Advice may be given as to whether or not the agency can prevail with a 402(a)(1) charge; but that will only happen if the question gets asked.  When guidance levels are set, a toxicological review may serve to establish that there is a risk, but the actual level is far more likely to be driven by practical limitations on what is feasible, rather than any semblance of a structured evaluation process.  However, all of that does not preclude the toxicologist from being blamed when somebody doesn’t think the agency is doing enough – which is inevitably what will happen when it is thought that regulating contaminants is just like regulating food additives, only with a different set of chemicals.

References

Hutt PB (1978).  Unresolved Issues in the Conflict Between Individual Freedom and Government Control of Food Safety.  Food Drug Cosmetic Law Journal 33:558-589.

Hutt PB, Merrill RA, and Grossman LA (2007).  Food and Drug Law: Cases and Materials, 3rd Ed.  Foundation Press, New York.

U.S. Food and Drug Administration (2015).  Compliance Policy Guides. Chapter 5 - Food, Colors, and Cosmetics

Official Post Soundtrack

Ozark Mountain Daredevils (1973).  Black Sky.  In: Ozark Mountain Daredevils, Track 8 

Post Note

Thesis #11, part of Regulatory Toxicology thread.  Soundtrack is from a scratchy needle drop - best I could do.