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Mozambique - Final Regulatory Action
Paraquat CAS number:
Date circular:

Chemical name: 4,4'-Bipyridinium, 1,1'-dimethyl-

Final regulatory action has been taken for the category: Pesticide

Final regulatory action: The chemical is Banned

Use or uses prohibited by the final regulatory action:

Ban all formulation and for all uses.

Pesticide use or uses that remain allowed:


The final regulatory action was based on a risk or hazard evaluation: Yes

Summary of the final regulatory action:

Based on the decision N. 001/DNSA/2014 paraquat was banned by the National Directorate of Agrarian Services from further import and use in Mozambique. The ban of all uses and the cancellation of the products containing paraquat in the country was decided due to the toxic nature and hazardous properties of this active substance, which combined with the local conditions of use can damage human and animal health and additionally cause potential damage to the environment The decision to cancel the registration of paraquat was taken as the last step of the project for Risk Reduction of Highly Hazardous Pesticides, which identified Highly Hazardous Pesticides that are registered in Mozambique. After consultations with different actors (public sector, private sector, civil society and others), cancelation of registrations and consequent non-approval for their use in Mozambique was approved.

The reasons for the final regulatory action were relevant to: Human health and environment

Summary of known hazards and risks to human health:

A project entitled Reducing Risks of Highly Hazardous Pesticides (HHPs) in Mozambique was initiated by the Government of Mozambique with the objective to reduce the risks associated with pesticide use in the country. The ultimate goal was to develop and implement an "HHP Risk Reduction Action Plan" for the most dangerous pesticides and use situations, resulting over time in the implementation of a variety of risk reduction measures based on a review of use conditions.
In the first step of the project, a review of all pesticides registered in Mozambique was carried out and a shortlist of highly hazardous pesticides was identified. This shortlist was based on an assessment of the hazards of the pesticides, based on criteria established by the FAO/WHO Joint Meeting on Pesticide Management (JMPM) (FAO/WHO, 2008).
Based on the hazard assessment in Step 1, a short list of HHPs, including "coming close" to HHPs, which were used in the country, was established.
Paraquat 200g/l (20%) SL pesticide formulation was on the short list as a pesticide "coming close" to HHPs based on the below indicated criteria:
-For liquid formulations: pesticide products with an acute oral LD50< 200 mg/kg or an acute dermal LD50< 400 mg/kg (note that these are the Class Ib limits in the previous version of the WHO Classification (WHO, 2005).
All pesticide formulations registered in Mozambique were classified using the oral and dermal LD50 value of the formulation, as provided in the registration dossier. LD50 values for the formulation were available or could be estimated for all registered pesticide products except for three microbial pesticides and one citronella oil (i.e. > 99% of the total).
Paraquat 200g/l (20%) SL pesticide formulation in Mozambique was identified as WHO class II, but chronic toxicity alert, dermal hazard was identified as close to Class Ib and very low AOEL (Come A.M. & van der Valk H., 2014). The a.i. was registered in US and banned for use in the European Union. In the case of paraquat, the WHO Classification notes in addition that it "has serious delayed effects if absorbed. It is of relatively low hazard in normal use but may be fatal if the concentrated product is taken by mouth or spread on the skin" (WHO, 2010). The occupational hazard of paraquat is confirmed by the very low Acceptable Operator Exposure Level defined in the EU (PPDB, 2012).
During the second step of the project, a pesticide use field surveys and exposure were carried out in selected regions and cropping systems in Mozambique. The main goal of the survey was to identify the conditions under which pesticides are being used in the country and their contribution to potential risks for human health and the environment.
The surveys (325 subsistence farmers interviewed) revealed that most of the farmers applied pesticides (95%), and that the conditions of use were likely to result in undue (excessive) exposure. Half of the farmers interviewed never received any training on pesticides use, and even the other half that did, often lacked understanding of the risks involved. Farmers were spraying vegetable crops at least 14 times per growing season. One out of three applications was involving one of the HHP containing formulation (Farmers using HHPs includes almost 30% of the interviewed farmers).
Also almost none of the farmers (93%) owned or wore adequate PPE having only one or no protective items at all. Only 2% of those applying HHPs wore adequate full body protection PPE. About half of the farmers had not received any training on the use of pesticides. The majority of pesticide applicators used manual sprayer (36%), followed by electric sprayer (with batteries); 33% and followed by inappropriate equipment such as watering can (13.5%) or other (unknown) means (12.5%). Approximately about half of the farmers surveyed reported that they noticed to receive pesticide on their clothes, bare skin or eyes when using pesticides. The main health symptoms associated with pesticide use by farmers noticing symptoms were headaches, skin rashes, burning eyes, vomiting, burning nose, blurred vision, dizziness and excessive sweating. Almost half of the farmers declared they did not read pesticide labels, including use instructions such as proper dosage and protective measures, the main reason being illiteracy. One out of four farmers poorly understood the hazard colour band on pesticide labels that indicates acute toxicity.
The survey results showed that the use of pesticides in general, and of HHPs in particular, was likely to result in excessive exposure of farmers in Mozambique. Therefore enforcing risk mitigation measures depending solely on wearing the appropriate PPE under the local conditions of use to be difficult and unlikely to give results.
The third step of the project consisted of a stakeholder consultation to further discuss the use and risks of highly hazardous pesticides in Mozambique and fine-tune the shortlist based on the survey results and the expertise and experience of stakeholders.
During the fourth step of the project, the risk of occupational exposure was assessed for a subset of the shortlisted pesticides, including paraquat. The subset included nine pesticides in seven different cropping systems using 13 application scenarios, each with and without personal protective equipment (PPE).
For the occupational risk assessment an estimate of operator exposure was made, which was then compared to a toxicologically acceptable level.
The exposure assessment used the registered dose rates and other application parameters for each pesticide based on farming conditions in Mozambique, including application with backpack sprayers (used in vegetables, tobacco, cereals and several other crops), hand-held rotary atomisers (used in cotton), and tractor- mounted sprayers. The exposure of pesticide applicators wearing full PPE that is realistically available in Mozambique was compared to the exposure of applicators wearing shorts and a T-shirt, as is often the case for smallholder farmers.
The toxicologically acceptable level of exposure applied in this study was the Acceptable Operator Exposure Level (AOEL), which is defined as the maximum amount of active substance to which the operator may be exposed without any adverse health effects (EC, 2006). The cropping systems that were evaluated are those for which the pesticide were registered. In some cases, crops were grouped together when the exposure to the pesticide were likely to be similar, based on height of the crop and the application method.
The volume application rates used in the model were generally those recommended on the label of the registered pesticide in Mozambique. If a volume application rate was not indicated on the label, 200 litres of pesticide mixture per ha was used as a default for EC or SC formulations applied with hydraulic nozzles or by air-assisted sprayers (high volume application). In the case of cotton applications, a scenario where 10 litres of mixture per ha was applied using rotary atomisers (low volume application) was also evaluated.
The dose rates used in the models were the highest rates recommended on the labels of the registered pesticide. In some cases where a wide range of dose rates was recommended, the lowest dose rate was also evaluated.
The risk of occupational exposure to pesticides was assessed, in particular when spraying the products. The risk of worker exposure (e.g. during harvesting) or bystander exposure was not evaluated. For the occupational risk assessment an estimate of operator exposure was made, which was then compared to a toxicologically acceptable level.
Exposure of pesticide applicators was estimated using occupational exposure models that are often applied in the European Union: the so-called "German model" and the "UK Predictive Operator Exposure Model" (UK-POEM) (Hamey et al. 2008; EFSA 2010). The models are different in their exposure calculations and also include different exposure scenarios. Therefore, both models are often used in parallel in the EU when assessing occupational exposure. Exposure scenarios and application parameters for the models were based on Mozambican pesticides application conditions.
Table 1. Details on the pesticides and cropping systems used in the operator risk assessments
Pesticide Concentration & type of formulation 1 Cropping systems Volume application rate (L mixture/ha) Dose rate (L or kg formulation/ha AOEL 2, 3 (mg a.i./kg bw/day)
Paraquat 200 g.a.i./L SL Sugar cane 200 3 0.0004 A
Bananas Vegetables 200 200 5 2.5
1 a.i. = active ingredient; WP = wettable powder; SL = soluble concentrate; WG -= wettable granules
2 bw = bodyweight
3 Sources of AOELs: A = FootPrint - Pesticide Properties Database (undated); B = Rotterdam Convention (2011); C = ERMA (2010)
- Expression of risk
The risk for the pesticide operator has been expressed as a risk quotient, which is the ratio between the estimated exposure of the operator to the pesticide (in mg a.i./kg bw/day) and the AOEL (in mg a.i./kg bw/day). A risk quotient > 1 implies that the risk is not acceptable; a risk quotient 1 implies an acceptable risk. For instance, a risk quotient of 100 means that the estimated exposure level of the operator, for the given pesticide application scenario, is a 100 times higher than the acceptable exposure level.
-Outcome of the risk assessments
The results of the pesticide operator risk assessments for paraquat are summarized in the table below. Risk quotients are given for the scenario when no PPE is worn during both mixing and spraying (worst case situation) and for the scenario with full PPE during both mixing and spraying (best practice situation). Crops were grouped together as crop structure and the application scenarios were considered similar.
Table 2. Outcome of the operator risk assessments for formulations containing Paraquat, a pesticide "coming close to a HHP".
Pesticide formulation Cropping system Application rate Exposure model Use of PPE Risk quotient
200 g/L SL Sugar cane 600 g a.i./ha UK - hand-held sprayer; low level target Mixing no; spraying no 1408
Mixing yes; spraying yes 255
UK - tractor-mounted boom sprayer; hydraulic nozzles Mixing no; spraying no 653
Mixing yes; spraying yes 95
Bananas 1000 g a.i./ha UK - hand-held sprayer; low level target Mixing no; spraying no 2268
Mixing yes; spraying yes 423
UK - tractor-mounted boom sprayer; hydraulic nozzles Mixing no; spraying no 1045
UK - tractor-mounted boom sprayer; hydraulic nozzles Mixing no; spraying no 1045
Mixing yes; spraying yes 155
Vegetables 500 g a.i./ha UK - hand-held sprayer; low level target Mixing no; spraying no 1193
Mixing yes; spraying yes 213
UK - home/ garden; low level target Mixing no; spraying no 203
The occupational risk assessments that were conducted showed that acceptable operator exposure levels were greatly exceeded for all crops and all pesticide application scenarios, irrespective of the application rate or use of PPE. This indicates that the application of paraquat likely poses a high risk under Mozambican use conditions.
-Occupational risks
The occupational risk assessments showed that the applications of six pesticides (among those paraquat) at registered dose rates would result in exceedance of acceptable operator exposure levels in all cropping systems that were assessed, both with and without PPE (Table 3).
Given the large risk quotient, it is unlikely that locally feasible mitigation measures would reduce the risk of paraquat to acceptable levels.
The occupational risk assessments reported in this study largely confirm that the majority of pesticide products identified as highly hazardous pesticides on the basis of hazard criteria would also lead to unacceptable occupational exposure on the basis of risk assessment.
Table 3. Summary of the results of the operator risk assessments.
Pesticide Formulation [type] (g a.i./L) Evaluated crops Evaluated application rates (g a.i./ha) Exceedance of AOEL
With PPE Without PPE
Paraquat 200 [SL] Sugar cane, bananas, vegetables 500 All cases All cases

Expected effect of the final regulatory action in relation to human health:

Reducing the risks posed by the use of HHPs in Mozambique in the context of human health. All registration of the Paraquat were cancelled.

Summary of known hazards and risks to the environment:

The Alterra study carried out by Wageningen University (WUR) analysed the following environmental hazard indicators: Environmental toxic load to aquatic organisms (fish, Daphnia, and algae), hazard to bees and groundwater leaching potential. The hazard assessment took into account the trends of registered pesticide imports in the country from 2002 to 2011 explored in terms of numbers (type) of pesticides and volume (amount) of pesticides. Paraquat was identified as pesticide of secondary concern based on the relative hazard to algae using the environmental toxic load (ETL) as a hazard indicator (details in Table 6, Table 1.3, Table 3.3, of Alterra report).
Environmental Toxic Loads (fish, aquatic invertebrates, algae, bees)
Secondary concern: Active ingredients of which the imported quantity of a.i. constitutes >10% of the total annual ETL value in 1 year or more.
Table 3.3: Active ingredients with the major contribution to the annual ETL for algae (i.e. > 0.5 %).
Year Rank Nr. Compound Nr. Compound name (kg) (%)
2002 1 128 Paraquat 1745 98.5
2003 2 128 Paraquat 4721 21.4
2004 2 128 Paraquat 7418 16.3
2005 2 128 Paraquat 5377 8.1
2006 2 128 Paraquat 6604 12.8
2007 2 128 Paraquat 4272 11.7
2008 2 128 Paraquat 4600 6.3
2009 2 128 Paraquat 8448 11.0
2010 2 128 Paraquat 4540 5.4
2011 2 128 Paraquat 7020 10.7

Expected effect of the final regulatory action in relation to the environment:

Significantly reduce the risk to aquatic organisms (algae) in Mozambique water basins.

Date of entry into force of the final regulatory action: 31/12/2014