There are no validated and regulatory accepted (animal) models to test for respiratory sensitization of low molecular weight (LMW) chemicals. Since several decades such chemicals are classified as respiratory sensitizers almost exclusively based on observations in workers. However, both respiratory allergens (in which process the immune system is involved) as well as asthmagens (no involvement of the immune system) may induce the same type of respiratory symptoms. Correct classification is very important from a health's perspective point of view. On the other hand, over-classification is not preferable in view of high costs to overdue workplace engineering controls or the chemical ultimately being banned due to Authorities' decisions. It would therefore be very beneficial if respiratory sensitizers can be correctly identified and distinguished from skin sensitizers and non-sensitizers/respiratory irritants. The purpose of this paper is to consider whether LMW chemicals can be correctly identified based on the currently available screening methods in workers, and/or via in silico, in vitro and/or in vivo testing. Collectively, based on the available information further effort is still needed to be able to correctly identify respiratory sensitizers and to distinguish these from skin sensitizers and irritants, not at least because of the far-reaching consequences once a chemical is classified as a respiratory sensitizer.

没有经过验证和监管认可的（动物）模型来测试低分子量（LMW）化学品的呼吸道致敏性。几十年来，几乎完全根据工人的观察将此类化学物质归类为呼吸道致敏剂。但是，呼吸道过敏原（涉及免疫系统的过程）和哮喘原（不涉及免疫系统）都可能诱发相同类型的呼吸道症状。从健康的角度来看，正确的分类非常重要。另一方面，考虑到逾期的工作场所工程控制成本高昂或由于当局的决定最终禁止使用该化学品，过度分类不是可取的。因此，如果能够正确地识别出呼吸道敏化剂并将其与皮肤敏化剂和非敏化剂/呼吸道刺激物区分开，那将是非常有益的。本文的目的是考虑是否可以基于当前工人可用的筛查方法正确地识别LMW化学品，和/或通过在硅片，在体外和/或体内测试。集体地，基于可获得的信息，仍然需要进一步的努力以能够正确地识别呼吸道敏化剂并将其与皮肤敏化剂和刺激物区分开，这至少不是因为一旦将化学品归类为呼吸道敏化剂会产生深远的后果。