In Hong Kong, people who need portable oxygen cylinders to breathe are denied access to public transport. Along with more than 400 other substances, compressed oxygen is classified under 'dangerous goods' in law. All dangerous goods are prohibited from public transport vehicles.

In the United States, the Code of Federal Regulations clearly states that transport providers may not prohibit anyone with a disability from travelling with a respirator or portable oxygen supply. Guidelines established in some developed countries, such as by the Canadian Transportation Agency, assist people with disabilities when travelling. Europe has guidelines specifically written to assist people travelling with medical oxygen.

Hong Kong actually has an ordinance listing exemptions to the conveyance of dangerous goods. However, the local public transport sector seems to find it much easier to use the by-laws to exclude all oxygen users from its services than to exercise its social responsibility and make reasonable accommodations for people with disabilities. The right to use public transport belongs to every member of society, despite any physical or social barriers that may exist. While most attention is given to improving the physical side of accessibility, little has been done to deal with the situation faced by oxygen users. For them, barriers to reintegrate into the community have more to do with rules.