The most characteristic point of food processing machines is that they require hygiene measures for risk reduction against contamination of manufactured food products for consumers, as well as safety measures for risk reduction to ensure safety for operators. The measures of risk reduction for safety aspects do not always match the risk reduction measures for hygiene aspects. The protective measures of safety aspects may increase the hygiene risk. Therefore, ISO 14159 has defined to decide the suitable protective measures for risk reduction by comparing both safety and hygiene. However, not only ISO14159 but also other standards do not illustrate a concrete method by comparing safety risk and hygiene risk. Harm contents differ between safety risk and hygiene risk, so methods of safety risk estimation are inapplicable to hygiene risk estimation. Consequently it has been an important issue in Food-processing machine industry to develop method of risk assessment by comparing the safety risk and hygiene risk, because of these circumstances. Authors devise the reduction measure of the hygiene aspects to be included in the process of the limits of the machine. We consider it is possible to perform both risk assessments, according to risk reduction process described in ISO 12100-1, without comparing both different risks. This paper mentions about the unprecedented assessment method including different risks.