Hazardous pesticides in Tanzania
— the limits of registration


The development of the pesticide registration process has had achievements in Tanzania. At the same time, there are constraints which expose the hazardous nature of pesticides in a developing country. Alcheraus Rwazo of the Tanzanian Tropical Pesticides Research Institute outlines what is being done to overcome these difficult problems.  


In an effort to reduce and control problems associated with production, use and handling of pesticides such as human and animal poisoning, environmental pollution and presence of residues in several places in Tanzania the parliament enacted the Tropical Pesticides Research Institute (TPRI) Act in 1979’, and in 1984 Pesticides Control Regulations were formulated under section 412. These regulations and part V of the Act constitute the Tanzanian pesticide law. Its objectives are twofold: to ensure that pesticides used in the country are effective against target pests and disease and to protect users, livestock and the environment against possible harmful effects. Before any pesticide is imported, manufactured, formulated, compounded. distributed, sold or used in the country, that it has to be registered. This article explains the procedures for registration and import, and requirements for labelling, packaging and handling, as well as offences and their corresponding penalties.


Registration procedure

All documents for pesticides registration are dealt with by the Registrar of pesticides at TPRI. However, recommendation and approval is done by the Pesticides Approval and Registration Technical Committee (PARTC) and TPRI Council respectively. PARTC draws members mainly from the Ministries of Agriculture and Health, University of Agriculture, Tanzania Bureau of Standards, National Environment Management Council and TPRI.

    The product is recommended and approved or rejected after thorough scrutiny and discussion which includes examining:  

  • the dossier submitted to) support the registration of the product. It should contain sunmmanes of toxicological, environmental (degradation, bioaccumulation) and efficacy data obtained from other countries;

  • the label specimen to be supplied with the product which should conform to Tanzanian labelling requirements;

  • a field trial which should contain bioefficacy data carried out by a reputable scientist from a recognised research institution in the country.

  •     If the product is approved, it is registered under a given category- after paytiment of the registratiom fee and the certificate is issued by the registrar. The product is then gazetted.

Registration categories:

Four categories of pesticide registration in Tanzania are currently recognised:


  • Experimental registration This category consists of products which are introduced iii the country for the first time and are being tested in the field and laboratory.


  • Provisional registration Products which have been approved for general use after successful local field trials fall into this category-. Apart fronm positive bioefficacy. products in this category’ must have mininmunm adverse environnmemital and toxicological effects. How-ever they are subject to further laboratory- and field tests.


  • Full registration This category consists of products upgraded from the Provisional Registration after being used for at least three years without causing any serious envtronmimemmtal and toxicological problems. Their fommulations must have been analysed and approved in the pesticide quality control laboratory’. Products in this category can be imported. fornmulated. mammufactured and sold in the country’.

  • Restricted registration Some products upgraded from Experimental Registration are placed iii the Restricted Registration category if they are very toxic, environmentally persistent and hio-accunmulative. These include organochlorines such as dieldrin and funmigammts (methyl bromide and alunuinium phosphide). The category’ also consists of technical nmatemials with hich active ingredient content immtenmded for use in fomniulation plammts. Recemmtly pyrethroid acaricides have also been restricted in order to avoid the developmmmemmt of acaricide resistance.  


When a product loses its registration, the cancellation is mainly for one of three reasons:  

  • the registrant requests cancellation of the product for coninmercial reasons. usually because it is not selling well:  

  • non-payment of registration fees;  

  • theme is evidence that the product is cans-inc serious adverse side effects. Some examples in this category include methyl-parathion, ethyl-parathion and aldicarb deregistered and banned due to their high toxicity and captafol for its high carcinogenic potential.

Table 1: Active ingredients approved for sale and use by Dec. 1994

organochlorine           8
organophosphate       21
carbamates                6
synthetic pyrethroids 10  
inorganic                   6
others                      42
Total                        93

Thus the number of registered products has been fluctuating, rising from 370 in 1986 to 668 in l992~ and then falling to 307 in 1994 (Table 1). By the end of 1994, there were about 93 different kinds of active ingredients registered and approved for sale and use (Table 2) including aldrin. dieldrin, campechlor (toxaphene). heptachlor. paraquat, lindane, EDB and chlordane which are among the hazardous ‘Dirty Dozen’ pesticides outlined by’ the Pesticides Action Network.


Pesticide poisoning incidents

Pesticide poisoning cases including intentional (suicidal and homicidal), accidental (through exposure) and food poisonings have been reported. For example in Amusha region in Northern Tanzania about 19 cases involving 223 people and 15 deaths were reported between 1974-1978 just before the pesticide law was enacted. Most cases were due to parathion and occasionally to dieldnin, diazinon. sumithion. aldrin and lindane4. In 1991 and 1992, 179 and 175 cases respectively were reported to the Chief Government Chemist and Thiodan (endosulfan) was a leading cause9. But since most cases are never reported these figures may be misleading. Twenty years ago (1976) the death toll due to pesticide poisoning was estimated at 1,000 per year1’, but without an investigation it is not possible to put a figure on current poisonings.


Table 2 Pesticides Registered in Tanzania by December 1994  
Registration category
Type of pesticide Full Prov. Rest Expt Total
insecticide 6 63 13 61 142
fungicide 3 23 2 40 68
herbicide 32  25  59
acaricide - 7 7 7 21
nematicide - 3 - 5 8
rodenticide - 1 - 4 5
avicide - 2 - - 2
growth regulator 1 - - 1 2
Total 11 131 22 143 307

Successes and limitations

Theme is no doubt that through enforcement of the pesticide law much has been achieved iii terms of pesticide registration. Despite such achievements there have been some failures as shown by the incidence of import for general use of unregistered and experimental pesticides. This has been due to: gaps in the pesticide law- which need a serious review, laxity’ on the part of customs officials and law enforcers, uncontrolled donations which sometimes include a package of pesticides, and liberalisation of trade leading to loopholes for importers.    

    Tanzania, like other developing countries needs further to intensify the enforcement of the law. In order to) succeed, central parties such as judiciary, customs and police force must be fully involved. TPRI is curmeumtly planning to conduct seminars at all border points with custom officials as a first step in this endeavour. Other pertinent issues relating to pesticide registration which should be critically considered in order to) improve the system are listed below.  

  • Funds should he available for the smooth operation of a registration scheme. Registmation fees should be strictly devoted to registration issues rather than diverting them to cover co)sts for other activities.

  • Dossiers should be updated as sonic still lack important information such as shelf-life, persistence in the environment, toxicological data, analytical methods for the active ingredient and precautions in handling the product.

  • Currently data is submitted in folders which are both bulky and less secure in terms of confidentiality. In order to modernise. registrants should submit data on computer disks which are more easy to handle and keep for future reference.  

  • At present, emphasis is put on bioefficacy data. Efforts should he made to involve fully trained analysts (for quality- assessment), and toxicologists (to evaluate human health risks) as well as environmentalists to assess residue levels and environmental risks.  

1.The TPRI Act, 1979, Act No. 16, in the Acts supplement of the Gazette of the United Republic of Tanzania, No. 51, Vol. LX:225-245. 

2. The Pesticides Control Regulations (1984) in the Government Notice No. 193, 12 October 1984.

3. Akhabuhaya J and Mkalanga H, Progress report on pesticide registration control in Tanzania, August 1993.

4. Maeda D, et. al., Increasing threat to human life, TPRI Misc., Report No. 974, June 1979.

5. Fupi V, Health aspects of pesticide mishandling, Tanzania Experience, Seminar on pesticides and other agrochemical, Dodoma, Tanzania, 3-6 May 1993.

6.  Madati P, Pesticide poisoning cases in Tanzania, Proceedings of the 1st East African Ent. Pest Control, Nairobi, 6-10 December 1976.

Alcheraus Rwazo is the Senior Scientific Officer at the Tropical Pesticides Research Institute, P0 Box 3024, Arusha, Tanzania.

[This article first appeared in Pesticides News No.27, March 1995, pages 8 & 17]

Email the Editor