By Shola Ogundipe

It was a hot day and the bumper- to- bumper traffic along the Oshodi-Apapa expressway did little to assuage the plight of hundreds of motorists caught in the late afternoon traffic as they sweated profusely, waiting impatiently to get past the failed portion of the road that was responsible for the gridlock.

But even as the traffic inched forward, scores of hawkers meandered through the long lines of vehicles, making brisk business as several trapped motorists and passengers made frenzied purchases from the assorted brands of packaged water and beverage drinks to douse their parched throats.

No one appeared bothered by the fact that the drinks they were consuming with relish had been kept for hours in less than ambient conditions. No one also  deemed it necessary to query the effect of exposure to the sun of the containers (usually plastic) on the liquid contents. But even if anyone had stopped to ask “what’s in this soft drink bottle?” or “what’s in that plastic container? The answer would probably have been lost in a chorus of “who cares?”
Concerns
Lately, concerns are being raised about the quality of the liquid contents within these bottles and the package they come in. Are they truly safe? Is the convenience of purchasing a bottle of table water or fruit juice or cola drink that has been left exposed in the sun for several hours really worth the health hazards?

The reason for this is not far-fetched. What you consume today determines your health tomorrow, so you need to ask if a beverage is a health-promoting choice.

Truly, many non-alcoholic beverage drinks out there in the market come under so many evocative names with labels depicting healthy living and promises of refreshment that convince the unwary consumer that the liquid within is the purest drink around.

But truth is that even though better regulated than most, are such packaged drinks indeed better and safer? The answers are varied.

Perceptions

When a friend who owns a nearby natural food store recently warned her that the plastic could leach chemicals into the drinks, she could not be bothered because they were still within the expiry date limit. But Funke Oluwasanmi, a housewife, actually knows about these risks, and she is perpetually worried as a result.
Funke hardly ever takes drinks stored in plastic containers. Rather, she uses a stainless steel flask to carry soft drinks and water even for her children’s needs. But it is a different tale for Taiwo Ademola, a trader, who is used to buying soft drinks in plastic containers in bulk and storing in the open space behind her house, where it is exposed to high temperatures.

Survey
A recent international survey on more than 1,000 bottles and over 100 brands of assorted beverage drinks on sale on the open market, found that at least one sample of a third of the brands contained bacterial or chemical contaminants, including carcinogens, in levels exceeding state or industry standards.

While the report noted that majority of the brands passed safety tests at the time packaging from the factories, drastic changes had occurred in the safety quality between then and the time of purchase and consumption. Interestingly, the survey found that samples of two top brands were contaminated. It is often recommended that certain drinks, for instance, quinine-containing drinks, should never be stored in sunlight.

Rule of the thumb

Based on the foregoing, it makes sense to assume that before anyone can conclude that their penchant for packaged or table water, or soft drinks or non-alcoholic drinks or packaged juice has no negative effect on their health, they should find out a few facts first. For one, has it been kept as cool as recommended?

Has it been adequately refrigerated below 4 degrees centigrade (not frozen)? By and large, the use of plastic containers to store carbonated and other non-alcoholic beverages has always been a big issue.

A rule of the thumb in health circles is that it is unhealthy to drink from a plastic bottle that’s been subjected to high temperatures (sitting in the car, for example). Besides, such bottles should never be stored anywhere they will be exposed to heat or chemicals.

PET vs PEN bottles
To make plastic more suitable material for making soft drink containers, several means of protection have been developed — first, to retain the clarity and physical properties, and second, to maintain the natural barrier properties to harmful effects of ultraviolet light in sunlight.

Two of the most popular non-limiting materials include Poly- Ethylene Terephthalate (PET) and Poly- Ethylene Naphthalate (PEN). Industry watchers say PET bottles are rather cheap and have acceptable barrier properties. On the other hand, PEN bottles have much better barrier properties than PET and also excellent mechanical properties.

Most soft drinks on the market come in PET bottles (check the bottle’s bottom). Due to new demands from the industry, suppliers of plastic bottles have begun to develop thin-walled PEN bottles which compete well with conventional PET bottles. Contents of a PEN bottle are better protected from sunlight than that of a PET bottle.

Light barrier
The reason for this is that the increased light barrier depends on the fact that PEN absorbs a greater amount of light at certain wavelengths. An increased absorbance of ultraviolet light as a part of the sunlight brings about the effect that PEN is more easily degraded, which in the polymer art is called photo-oxidative degradation. Hence ultraviolet stabilisers must be added to several of the most usual polymers, if they are to be used in an outdoor environment subjecting them to sunlight.
Hazing
In the case of PEN bottles, degradation due to exposure to sunlight is really a problem.

The sunlight degrades the outer surface layer of the plastic bottle creating an uneven surface which, when viewed under a microscope, has very small crater-like voids, which are invisible to the naked eye.

Due to a diffuse reflection, this uneven surface appears as haziness to a viewer. It is wise to refuse buying a bottle having such haziness because , hazing of such bottles is disadvantageous.

Plastic safety
Although plastic bottles are generally safe, environmentalists however warn that when stored in hot or warm temperatures, a plastic bottle may leach chemicals into the water. One of such undesirable constituents are Phthalates—- common chemicals used to make plastic softer, and also found in cosmetics and fragrances, even baby toys. They have been under increasing scrutiny because of their strong connection as endocrine disrupters, which mean they block or mimic hormones, affecting the body’s normal functions.

Potential risk
But evidently, high temperatures in storage space aren’t the only potential risk. Experts warn against storing drinks in plastic bottles in places such as the garage, near gas fumes, pesticides and other chemicals that could, at the very least, affect the smell and taste of the liquid content.

It’s not just where the drinks are stored, but what you do with the drink in the container as you carry it with you. Many people sip from a bottle that’s been sitting in a hot car, a potentially dangerous move because leaving bottled water or soft drink in a car’s hot interior changes the chemical equilibrium so that materials from the plastic go into the water faster.