暑期租房旺季到来，部分租客在入住后遭遇甲醛超标、墙体渗水、霉菌滋生等问题[1]。由于看房时间有限，租客往往难以在短时间内察觉这些隐蔽的房屋缺陷。租客叶旻因甲醛超标出现身体不适，定金1000元至今未能追回；租客龙依梵发现租住的房屋甲醛超标1.5倍，房东虽然返还了押金和租金，但搬家等相关损失超过3000元仍由租客自行承担[1]。
根据民法典第708条规定，出租人应当按照约定将租赁物交付承租人，并在租赁期内保持租赁物符合约定用途[1]。这意味着房东有义务保证房屋符合基本居住安全标准，租客因甲醛超标等危害健康的情形可以无条件解约并要求退款[1]。上海市第二中级人民法院的一起案例显示，即使房东以检测时非空房状态为由拒绝返还定金，法院仍判决房东全额返还4.1万元定金[1]。
为了有效规避风险，律师建议租客在签约时将空气质量不达标或存在渗漏、霉变问题时的无责解约权明确写入合同[1]。此外需要注意的是，甲醛释放是一个长期过程，温度越高、湿度越大，释放量就越大[1]。
As the summer rental season intensifies, numerous tenants have encountered substandard housing conditions including formaldehyde contamination exceeding safe levels, water seepage, and mold proliferation.[1] These issues often remain undetected during brief viewing periods, leaving renters vulnerable to health hazards after signing leases.
Tenant Ye Min experienced significant health problems after moving into a rental unit with excessive formaldehyde levels and has been unable to recover a 1,000 yuan deposit.[1] Another renter, Long Yifan, discovered formaldehyde concentrations 1.5 times above acceptable standards in her apartment; while the landlord eventually returned the security deposit and rent, Long bore approximately 3,000 yuan in moving and related expenses herself.[1] According to China's Civil Code Article 708, landlords are obligated to deliver rental properties in compliance with contractual terms and maintain them suitable for their intended purpose throughout the rental period.[1] Formaldehyde release represents a prolonged process intensified by higher temperatures and increased humidity.[1]
Legal precedent supports tenant protections in such cases. A Shanghai Intermediate People's Court ruled that a landlord must return a 41,000 yuan deposit in full, rejecting the landlord's claim that the property could not be properly assessed because it was occupied during testing.[1] Legal experts recommend that tenants explicitly include provisions in rental agreements establishing the right to terminate without penalty if air quality standards are not met or if seepage and mold issues are present.[1] Under civil law provisions, renters may unilaterally terminate rental agreements without penalty and demand full refunds when formaldehyde contamination or other health hazards exist.[1]