CONCLUSION ON PESTICIDE PEER REVIEW Conclusion regarding the peer review of the pesticide risk assessment of the active substance aluminium phosphide Issued on 29 September 2008

Aluminium phosphide is one of the 84 substances of the third stage Part B of the review programme covered by Commission Regulation (EC) No 1490/20021. This Regulation requires the European Food Safety Authority (EFSA) to organise upon request of the EU-Commission a peer review of the initial evaluation, i.e. the draft assessment report (DAR), provided by the designated rapporteur Member State and to provide within six months a conclusion on the risk assessment to the EU-Commission. Germany being the designated rapporteur Member State submitted the DAR on aluminium phosphide in accordance with the provisions of Article 10(1) of the Regulation (EC) No 1490/2002, which was received by the EFSA on 19 June 2007. The peer review was initiated on 29 October 2007 by dispatching the DAR for consultation of the Member States and the applicants Casa Bernardo, Detia Freyberg GmbH and United Phosphorus Ltd. Subsequently, the comments received on the DAR were examined and responded by the rapporteur Member State in the reporting table. This table was evaluated by EFSA to identify the remaining issues. The identified issues as well as further information made available by the applicant upon request were evaluated in a series of scientific meetings with Member State experts in June - July 2008. A final discussion of the outcome of the consultation of experts took place during a written procedure with the Member States in September 2008 leading to the conclusions as laid down in this report. This conclusion was reached on the basis of the evaluation of the representative uses as an insecticide, rodenticide, talpicide and leporicide as proposed by the notifier. Full details of the GAP can be found in the attached list of endpoints. The representative formulated products for the evaluation were "Phostoxin Tabletten", "Quickphos tablet/pellets/bags 56 GE", and "Gastoxin" gas generating products (GE). The gas phosphine that is produced is the true active ingredient. Pooling all the available data from all aluminium phosphide applicants a method of analysis for phosphine in products of plant origin is available; however ILV and a confirmatory method have been identified as a data gap. A method for products of animal origin is not required as MRLs have not been set. Methods for phosphine in soil are not required as the DT90 in soil is < 3 days for phosphine. A method is available for phosphine in water but a confirmatory method has been identified as a data gap. It should be noted however, that there is a confirmatory method in the magnesium phosphide DAR. The method of analysis for air did not have a low enough LOQ and a data gap was identified. Sufficient analytical methods as well as methods and data relating to physical, chemical and technical properties are available to ensure that quality control measurements of the plant protection products are possible. The meeting of experts considered the specification and impurities on the basis that the spent pellets were contained and removed from the treated material. Therefore, given the toxicity of phosphine, possible relevant impurities were ignored. The case where the spent material is not removed has not been considered in the peer review process. The batch data and the specification for the Casa Bernardo sources were not accepted. Some data gaps for physchem data for the individual formulations were identified. The mammalian toxicology of aluminium phosphide was assessed in a series of tests. When coming into contact with moisture aluminium phosphide decomposes to aluminium hydroxide and phosphine, which is the toxicologically active ingredient and the relevant component for the assessment of mammalian toxicology of aluminium phosphide. Aluminium phosphide is classified as R29 "Contact with water liberates toxic gas" and R32 "Contact with acids liberates very toxic gas". Phosphine is rapidly absorbed from the gastrointestinal tract and the lungs. It is widely and evenly distributed in the body and has no potential for accumulation. Phosphine is excreted as such via expired air or with the urine in form of hypophosphite or phosphite. Aluminium phosphide is very toxic by the oral and inhalation route and harmful by the dermal route. It is neither a skin nor an eye irritant nor a skin sensitizer. Based on data on acute toxicity a classification as T+; R28 "Very toxic if swallowed", Xn; R21 "Harmful in contact with skin" and T+; R26 "Very toxic by inhalation" is proposed. A short term NOAEL of 1.1 mg/kg bw/d (the highest dose tested, no adverse effects observed) was derived for phosphine from a rat 90-day inhalation study. Aluminium phosphide is not genotoxic. In a 2-year inhalation study with rats a NOAEL of 1.1 mg/kg bw/d was established for phosphine which was the highest dose level tested since no adverse effects were observed. A mouse carcinogenicity study was not carried out and not considered necessary based on the toxicity profile of the substance (lethality anticipated at low doses). In an inhalation developmental study with rats (a rabbit study was not provided) no specific developmental effects were observed and an overall NOAEL for phosphine of 1.9 mg/kg bw/d was set based on mortality occurring in dams. Effects on reproduction have not been assessed but are, based on the toxicity profile of the substance, not anticipated. The acceptable daily intake (ADI) and the acceptable operator exposure level (AOEL) have been set at 0.019 mg/kg bw/d. The acute reference dose (ARfD) was fixed at 0.032 mg/kg bw. The corresponding values for phosphine are 0.011 mg/kg bw/d (ADI and AOEL) and 0.019 mg/kg bw (ARfD). When applying aluminium phosphide containing formulations in rodent burrows without the use of respiratory protective equipment (RPE) maximum exposure levels amounted to 93% of the AOEL for operators, workers and bystanders, however more realistic exposure levels for workers and bystanders presented in the DAR accounted for 63% and 33% of the AOEL respectively. Application of aluminium phosphide in storage rooms when respiratory protective equipment is used amounted to 71% for operators and to 33% (or alternatively to 25%) for workers of the systemic AOEL. For unprotected bystanders a maximum value for exposure of 33% of the AOEL was derived. Two main uses of aluminium phosphide were evaluated, 1) as rodenticide, talpicide, leporicide to control rodent and non-rodent vertebrates by fumigation of underground tunnels and burrows in cropland and non-cropland situations, 2) as fumigant to control insects in various harvested plant products and in empty warehouses or transportation facilities. Due to its physico-chemical properties, no specific studies to evaluate metabolism and distribution of aluminium phosphide in treated commodities were submitted. In contact with soil or atmospheric moisture, aluminium phosphide is rapidly hydrolysed to produce phosphine (PH3) and aluminium hydroxide Al(OH)(3). After treatment the major part of phosphine is volatilised and diluted in air or oxidised to phosphorous oxyacids of no significant concern for human health. Considering stored fumigated commodities may contain residual gaseous phosphine and residual metal phosphide, the residue definition for monitoring and risk assessment was set as "phosphine and phosphine generators (relevant phosphide salts) determined and expressed as phosphine". No residue trials were submitted to support the uses of aluminium phosphide as a rodenticide, considering that the direct application of the active substance into underground tunnels of rodent or non-rodent animals excludes the direct contact with plants and therefore, the possible residues in plants. For post harvest applications, in addition to the aeration period, the RMS proposed for each commodity or group of commodities a withholding period. Thus, during the meeting, the MRL proposals were not discussed on the basis of the residue levels observed at the end of the aeration period as stated in the GAP, but at the end of these additional withholding periods of 7 to 35 days, depending on the commodities. Consequently and after the meeting, EFSA was of the opinion that the fumigation practices have not been sufficiently defined to allow MRL setting, and considers the fact that the withholding periods were not clearly described in the intended GAP as a data gap. No storage stability study was provided considering that the inherent properties of phosphine lead to a low stability in stored products. No processing studies and no livestock metabolism and feeding studies were provided since no significant residues of aluminium phosphide and phosphine are expected in post harvested plant commodities. No rotational crop studies were submitted since no residues in soil are expected from the outdoor uses on rodent and non-rodent vertebrates. No chronic or acute risks to consumers are expected after fumigation of stored commodities with aluminium phosphide if a withholding period is taken into account in the GAP, and considering that the proposed MRL values do not reflect the critical GAPs as initially defined by the applicants. When placed in animal burrows (i.e. the soil environment) aluminium phosphide will rapidly hydrolyse producing phosphine gas and aluminium salts. The phosphine gas produced, which was shown to exhibit very low persistence, will volatilise to the atmosphere or adsorb to soil and be converted to phosphate anions. Any phosphine gas that reaches the upper atmosphere will be subject to indirect photooxidation to phosphonic acid and phosphoric acid that would be removed from the atmosphere by wet deposition. The rate of indirect photooxidation of phosphine measured was rapid enough to indicate that phosphine will not be subject to long range atmospheric transport. The potential for groundwater exposure of aluminium phosphide and its breakdown products above the relevant parametric drinking water limits set out in the relevant EU legislation(2) was assessed as low from the applied for intended uses. There is a potential for surface water exposure by phosphine gas when treated target organism burrows are adjacent to surface water (via movement in the gas phase). A data gap was identified to better characterise this exposure potential. Due to the representative uses (applied outdoor directly into the burrow systems or indoor in food storage rooms), the exposure to non-target species was considered to be only local or negligible. On the basis of the potential exposure of surface water to phosphine where target organism burrows are adjacent to water bodies, the risk from the outdoor use to aquatic organisms needs to be addressed and therefore valid studies for invertebrates and algae should be provided. The risk to birds, mammals, bees, non-target arthropods, earthworms, soil non target macro- and micro- organisms, non-target plants and biological methods of sewage treatment was expected to be low for the representative use evaluated.