2023年12月20日，据欧盟食品安全局（EFSA）消息，应欧盟委员会要求，欧盟动物饲料添加剂和产品（FEEDAP）研究小组就从凯泽施图尔火山岩中提取的钠沸石-响石（natrolite–phonolite）作为所有动物饲料添加剂的安全性和有效性发表科学意见。
经过评估，由于缺乏数据，专家小组无法就添加剂对目标物种、消费者和使用者的安全性得出结论，也无法对添加剂的功效做出结论。部分原文报道如下：
Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of natrolite–phonolite obtained from volcanic rock from Kaiserstuhl as a technological additive (functional group: anticaking) for all animal species. According to the conventional risk assessment, due to the lack of adequate data, the Panel is not in a position to conclude on the safety of the additive for the target species under the proposed conditions of use. However, from the tolerance studies in cattle for fattening and weaned piglets, effects observed in animal performance and blood clinical biochemistry suggest adverse effects on the animals supplemented with the additive. based on current knowledge, there is no indication of substantial absorption of the components of the additive and, therefore, of concern for the consumer. The FEEDAP Panel is not in the position to conclude on the potential of the additive to be a skin and eye irritant. The additive is considered a respiratory and dermal sensitiser. In the absence of suitable data, the presence of small/nanoparticles cannot be excluded. As no suitable data in line with the requirements of the Guidance on risk assessment of nanomaterials were provided by the applicant, the potential risks associated with the presence of nanoparticles for the target species, the consumer and the user could not be assessed. Due to the lack of sufficient data, the Panel is not in a position to conclude on the efficacy of the additive.
