## 7 Risk Assessment
### Estimated Daily Intake and Tolerable Daily Intake  
The exposure assessment from FCMs is typically derived from migration studies using standardized food simulants under controlled conditions (as seen in Section 4.1). The migration values obtained (usually in mg/kg of the food simulant) are then translated into human exposure scenarios as the estimated daily intake (EDI) by applying conventional assumptions. These include a food packaging surface-to-food mass ratio of 6 dm\({}^{2}\)/kg, a daily intake of 1 kg of packaged food per person, a consumption factor (CF) representing the fraction of the daily diet for a specific material, and a default body weight (bw), which is commonly 60 kg for adults in European assessments [83]. However, these default values may not adequately reflect sensitive or high-exposure populations, such as infants, toddlers, or pregnant women. For instance, infants have higher food consumption relative to their body weight, potentially leading to proportionally greater exposure, especially in scenarios involving baby food packaging [7; 83]. Accordingly, the EDI is calculated using the following expression:  
\[\text{EDI}\left(\text{mg}/\text{kg}\;\text{bw}/\text{day}\right)=\left[\text{ Migration}\left(\text{mg}/\text{kg}\;\text{food}\right)\times\text{Food intake}\left(\text{1 kg}/\text{day}\right)\times\text{CF}\right]/\text{bw} \tag{1}\]  
Once the EDI of a substance migrating from FCMs is calculated, it is compared with available toxicological reference values, most commonly the tolerable daily intake (TDI), which represents the amount of a substance that can be ingested daily over a lifetime without appreciable health risk. TDIs are often established by authorities, such as the European Food Safety Authority (EFSA), the U.S. Environmental Protection Agency (EPA), or the World Health Organization (WHO), based on toxicological studies and the application of safety factors to account for uncertainties [84]. In cases where a TDI is available, the hazard quotient (HQ) is used as an indicator to assess risk. The HQ is calculated as the ratio between the estimated exposure and the TDI as described in the follow equation:  
\[\text{HQ}=\text{EDI}/\text{TDI} \tag{2}\]  
An HQ value of \(<\)1 suggests that exposure is within the acceptable safety margins and is unlikely to pose a risk, whereas an HQ value of \(\geq\)1 may indicate potential concern and warrants further investigation. For example, if an EDI of 0.002 mg/kg bw/day is estimated for a substance with a TDI of 0.01 mg/kg bw/day, the HQ would be 0.2, implying no immediate risk under current exposure assumptions. In the work conducted by [PERSON] et al. [34] the TDI values for melamine and formaldehyde from EFSA [85; 86] were applied to evaluate the risk associated with the migration of these substances from melamine-formaldehyde utensils after UV irradiation, using consumption and food-type distribution factors based on the U.S. Food and Drug Administration (FDA) guidelines [87]. As only one food simulant was used, the food-type distribution factor was set to one. EDI values were compared to the TDI to assess potential health risks. Results indicated that melamine exposure (EDIs) ranged from 0.14% to 1.36% of the TDI in the control conditions and 0.26 to 11.78% under UV exposure. For formaldehyde, exposure ranged from 1.99 to 3.95% in the control samples and 2.23 to 7.95% under UV exposure. These values demonstrate that the migration levels of both compounds remain well below the respective TDI thresholds, indicating a low health risk for consumers under the tested conditions. However, these results did not account for the statistical uncertainty associated with EDI estimates, such as confidence intervals or variability in migration measurements, which may impact the interpretation of risk, especially near regulatory thresholds. Limitations exist, particularly when TDIs are lacking, as is common for many NIAS, or when data are insufficient for full hazard characterization. In such cases, alternative approaches like the TTC are applied.