Pesticides

Tea, especially green tea, tends to be accused by some institutions as polluted with pesticides and, therefore, as being unhealthy.
Especially consumer watch groups tend to interpret the test results in uncorrect ways. The pollutants are caused by the use of pesticides.

What are pesticides?

Generally speaking, all plant protection products are pesticides if they are produced artificially!
The plant protection products can be categorised in 3 groups:
Herbicides: weed control
Insecticides: pest control
Fungicides: combat fungal infestation and leaf diseases

With respect to tea, insecticides are almost always referred to.
Generally speaking, all three groups, including the heavy metals, should be investigated. Pesticides are used worldwide in all areas of the agriculture today. The chemical industry produces several hundred presticides. Many of these substances are already forbidden in many countries. However, many of these substances remain in the soil for a long period of time and are very persistent in that they still affect the plants after several years. Of course, in many so-called Third World countries, a large number of questionable or even poisonous pesticides are still used if the importing countries do not exert pressure against this.

Examinations, tests and regulations

Based on the much more sensible methods of analysis which can be used today, it is possible to find even the smallest residues of pesticides on the plants. Tea is generally analysed with respect to a certain number of possible pesticides. Hereby, a certain maximum amount per pesticide is determined by the EU. These residue amounts are definitely binding and regulated by the the RHmV in Germany.
The amounts of the pesticides which are present are only written down if a certain maximum amount is surpassed. Apart from this, the amounts are declared as "smaller than" or "n.n." (not traceable).

These analyses also often provide the ground for misinterpretations. Especially journalists like to publish and interpret these analyses. It is then often the journalists and not the experts who arrogate to appraise and judge the teas using their own, arbitrary measurements. Particularly the setting of subjective judgement criteria, such as slightly polluted or questionable, is hereby especially confusing. Traces of pesticides or heavy metals are nowadays unfortunately everywhere, i.e. in every foodstuff. Subsequently, the label "pesticide-free" is wrong and confusing.

When interpreting the analytic data of the residue analyses, some details have to be taken into account: the results of the residue analyses vary quite a lot due to
– the very small amounts which are to be identified and quantified,
– the type of the material which was analysed, which is often very inhomogenous
– the differing quality standards of the laboratories. According to the statement of a laboratory, fluctuations of up to 60% (+/-) are definitely possible!

Due to this, the foodstuff examination office declared the range of variaton at 50% +/-. This means that a trespassing of the peak amount is only given if the entire range of variation lies above the peak amount and also does not touch it.

Additionally, it has to be noted that only about 2-15% of the pesticide residues, which can be found in the tea leaf, are solved and can be found in the infusion. The largest proportion remains unsolved in the leaf. Hence, a pesticide pollution of tea has to be rated differently than in other foodstuff which is consumed in its entirety.

Unfortunately, and paradoxically, the accepted amounts are higher for some foodstuff which is consumed in its entirety than for tea.
For example, up to 2,0 mg/kg of Lindan may be contained in leaf salad. With respect to tea, the maximum amount allowed for Lindan is 0,2 mg/kg. If you then consider that only about 2-15% of the residue on the leaf is solved in the tea, it is almost neglectable to even talk about.

In the important tea producing countries which also have a large per capita amount of tea consumption (such as Japan), strict rules are also in place according to the cleanliness and purity of the product. However, in these countries, the basis of the analysis is always the Eluat, that is, the infusion of the tea, which much more represents the reality.

A brief description of the residues on tea.

chloride pesticides
are acutely poisonous and even small doses lead to long-term damage and cancer. The most frequently used chloride pesticide is DDT. The smallest amounts of this are deposited in fat tissue and need years to be broken down. Hence, the use of pesticides is highly problematic and has been forbidden by many tea cultivating countries for years. Therefore, the pesticide residue analysis is only of limited relevance to tea nowadays and it is more important in how far the soil is still polluted with the pesticides which were used years ago.
Some more widely known chloride pesticides are, for example, DDT, isodrin, endirn, triallat.

cyanogene pesticides
A group of pesticides which appears frequently and which has a highly toxical effect on the human organism. They, however, have not been playing any major role in tea cultivation for many years.

phosphorous pesticides
This is a group of highly toxical, but biologically degradable substances such as ethion. They are broken down quickly in the soil and, therefore, are only of a short relevance, e.g.: carbophenothion, chlorthion, diazion, ethion, phosalon

heavy metals
Especially copper combinations cause a stir with respect to residues in tea. Copper salt is highly toxic and also responsible for long-time damages in the liver. Generally, however, heavy metals are only detectable in tea in very small doses. Their effect on the human organism is almost non-existant.

KbA – controlled organic cultivation

The label kbA refers to the cultivation methods which are controlled, and not to the possible residues on the product. That means, a product with a “ kbA“ label may contain residues of pesticides and heavy metals.

What is meant by controlled organic cultivation?

Controlled organic cultivation of natural plant families, the support of organic plant protection products. Synthetic spray and fertilizing substances are forbidden under kbA.

The conversion from conventional cultivation to organic agriculture can be achieved in three years.
After the so-called first inspection where all fields are analysed with respect to the soil, plants and harvests, the so-called "zero year" begins. During this year, the cultivation may not be called organic, even though all the rules which apply to organic cultivation have to be followed. This is a difficult phase for the tea cultivator, because the costs are significantly higher even though the prices may not be adapted to this new situation.

The phase of the “Cultivation with respect to the switch to controlled organic agriculture" lasts from the beginning of the second year until the end of the third year. During this period, the product may already be labeled: produced with respect to the switch to controlled organic cultivation".

After the successful finalisation of the three-year conversion, the products may now be called "from controlled organic cultivation".

Without doubt, the chemical industry is, of course, interested to sell pesticides to the agricultural industry worldwide. On the other hand, the ambitions to replace these substances have increased within the last few years. New tendencies in conventional cultivation are, for example, the use of a new generation of pesticides, such as the fenfalerates. These belong to the so-called pyrethroids which are substances which are extracted from descendents of African carnicerous plants. These substances are organically degradable and can be consumed by humans. In more and more tea gardens and plantations these methods are used extensively and allow strict organic cultivation. For example, straw and bast mats are laid out against vermins and insecticides are exchanged or natural insect eaters such as frogs or lizards.