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Mozambique - Final Regulatory Action
2,4-D-dimethylammonium CAS number:
2008-39-1
Date circular:
12/12/2020

Chemical name: Acetic acid, (2,4-dichlorophenoxy)-, compd. with N-methylmethanamine (1:1)

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:

None

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 2,4-D-dimethylamine 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 2,4-D dimethylamine 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 2,4-D-dimethylamine 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 ban and non-approval for their use in Mozambique was approved.

The reasons for the final regulatory action were relevant to:

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.
2,4-D dimethylamine 720g/l (72%) 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).
2,4-D dimethylamine 720g/l (72%) SL pesticide formulation in Mozambique was identified as WHO class II, but dermal hazard was identified as close to Class Ib (Come A.M. & van der Valk H., 2014). The a.i. was banned in US and approved for use in the European Union.
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 2,4-D dimethylamine. 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.
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 (2,4-D dimethylamine)
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)
2,4-D dimethylamine 720 g a.i./L SL Palm tree, cocoa, coconut 200 3 0.15 A
Cabbage, rice 200 3
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 2,4-D dimethylamine 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). Table 2 shows the results for the application of the herbicide 2,4-D dimethylamine in palm trees, cocoa and coconut, and in cabbage and rice. Crops were grouped together as crop structure and the application scenarios were considered similar. The occupational risk assessments that were conducted showed that acceptable operator exposure levels were exceeded for all crops and all pesticide application scenarios. In the cases when PPE was used, or when applying the herbicide in the home/garden scenario, limited exceedance of the AOEL was estimated, of about a factor 2.5.
Table 2. Outcome of the operator risk assessments for formulations containing 2,4-D dimethylamine, a pesticide "coming close to a HHP".
Pesticide formulation Cropping system Application rate Exposure model Use of PPE Risk quotient
720 g/L SL Palm tree Cocoa Coconut 2160 g a.i./ha UK - hand-held sprayer; low level target Mixing no; spraying no 14
Mixing yes; spraying yes 2.5
Cabbage Rice 2160 g a.i./ha UK - hand-held sprayer; low level target Mixing no; spraying no 14
Mixing yes; spraying yes 2.4
UK - home/ garden; low level target Mixing no; spraying no 2.3
The occupational risk assessments showed that the application of 2,4-D dimethylamine, 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).
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
2,4-D dimethylamine 720 [SL] Palm tree, cocoa, coconut, cabbage, rice 2160 All cases All cases
2,4-D dimethylamine and the products containing this a.i. were considered harmful for the human health under the local conditions of use in Mozambique requiring risk mitigation measures. Therefore the authorities decided to ban the a.i. 2,4-D dimethylamine from future use in the country and to cancel the registration of all the products containing it.

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 2,4-D dimethylamine products was cancelled.

Summary of known hazards and risks to the environment:

N/A

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

N/A

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