Dermal exposure Clause Samples
Dermal exposure. Potential non- occupational dermal exposure to Aspergillus flavus NRRL 21882 is unlikely because the use sites are commercial and agricultural, not residential, and because of the granular nature of the pesticide, which minimizes pesticide drift. As discussed earlier (see Unit III.), lack of hypersensitivity incidents, low application rates, and the return of levels of Aspergillus flavus to background levels shortly after germination, leads EPA to conclude that this pesticide poses minimal risk to human populations via non- occupational dermal exposure, which exposure is expected to be no greater than the existing exposure to Aspergillus flavus at current levels.
Dermal exposure. The conceptual model for dermal exposure is illustrated in Figure 6 and describes how the application of a plant protection product can eventually result in dermal exposure. The application of a PPP will result in an initial deposit on the crop because the spraying liquid is partially intercepted by the crop. A fraction of the deposit will not reach the target (i.e. the crop), but will be lost due to drift or will be deposited on the soil. Re-entry workers can come into contact with the deposit on the crop during re-entry activities such as harvesting. Re- entry however usually doesn’t take place immediately after application but sometime after the application. The time period between application and re-entry is known as the re-entry interval. During this interval, processes such as degradation and volatilisation may take place, resulting in a reduction of the initial deposit on the crop while dry (dust) or wet (rain) deposition may contribute to the deposit on the crop. When the worker re-enters the crop and makes contact with the crop, a fraction of the remaining residue is dislodged and transferred from the crop to the worker, resulting in dermal exposure. The extent of the exposure is mainly influenced by the intensity of the contact with the crop, the amount of dislodgeable residue on the crop and the duration of the contact. A certain amount of spray liquid will not reach the crop but will be deposited on the soil. Similar to the deposit on the crop, the amount of (available) residue on the soil will decrease during the re-entry interval due to processes such as degradation or sorption to the soil. Wash-off from the crop and deposition from the air may on the other hand contribute to the deposit on the soil. During activities that involve contact with the soil (e.g. weeding), dermal exposure can take place when small amounts of soil adhere to the skin and the substance is transferred from the soil to the worker. When making contact with the crop or soil, the skin of the worker can either be bare or covered by clothing and/or Personal Protective equipment (PPE). Clothing and PPE provide the worker a certain level of protection, because only a fraction of the transferred PPP migrates through the clothing and PPE and reaches the skin. Only a fraction of the substance that reaches the skin will penetrate the skin and be absorbed into the internal system of the worker. At this point, it is important to emphasize to difference between potential dermal ex...
Dermal exposure. Dermal exposure is estimated by assuming that the level of exposure depends of the amount of residue present on the crop, the amount of contact with the crop and the duration of exposure. First, the algorithms used to estimate dermal exposure are described. Next, the input parameters used in these algorithms are discussed in more detail.