Article 4: Ban on slavery

No one shall be held in slavery or servitude; slavery and the slave trade shall be prohibited in all their forms.

Definitions of the ban on slavery

The ban on slavery is enshrined in 
Article 4 of the Universal Declaration of Human Rights.

The right is enshrined in Article 8 of the International Covenant on Civil and Political Rights:

1. No one shall be held in slavery; slavery and the slave- trade in all their forms shall be prohibited.
2. No one shall be held in servitude.
3. (a) No one shall be required to perform forced or compulsory labour;
(b) Paragraph 3 (a) shall not be held to preclude, in countries where imprisonment with hard labour may be imposed as a punishment for a crime, the performance of hard labour in pursuance of a sentence to such punishment by a competent court;
(c) For the purpose of this paragraph the term "forced or compulsory labour"; shall not include:
(i) Any work or service, not referred to in subparagraph (b), normally required of a person who is under detention in consequence of a lawful order of a court, or of a person during conditional release from such detention;
(ii) Any service of a military character and, in countries where conscientious objection is recognized, any national service required by law of conscientious objectors;
(iii) Any service exacted in cases of emergency or calamity threatening the life or well- being of the community;
(iv) Any work or service which forms part of normal civil obligations. 

The right is also contained in Article 11 of the International Convention on the Protection of the Rights of All Migrant Workers and Members of Their Families:

1. No migrant worker or member of his or her family shall be held in slavery or servitude.
2. No migrant worker or member of his or her family shall be required to perform forced or compulsory labour.
3. Paragraph 2 of the present article shall not be held to preclude, in States where imprisonment with hard labour may be imposed as a punishment for a crime, the performance of hard labour in pursuance of a sentence to such punishment by a competent court.
4. For the purpose of the present article the term "forced or compulsory labour" shall not include:
(a) Any work or service not referred to in paragraph 3 of the present article normally required of a person who is under detention in consequence of a lawful order of a court or of a person during conditional release from such detention;
(b) Any service exacted in cases of emergency or clamity threatening the life or well-being of the community;
(c) Any work or service that forms part of normal civil obligations so far as it is imposed also on citizens of the State concerned.

The Convention on the Rights of Persons with Disabilities contains this right in Article 27:

1. States Parties recognize the right of persons with disabilities to work, on an equal basis with others; this includes the right to the opportunity to gain a living by work freely chosen or accepted in a labour market and work environment that is open, inclusive and accessible to persons with disabilities. States Parties shall safeguard and promote the realization of the right to work, including for those who acquire a disability during the course of employment, by taking appropriate steps, including through legislation, to, inter alia: 
(a) Prohibit discrimination on the basis of disability with regard to all matters concerning all forms of employment, including conditions of recruitment, hiring and employment, continuance of employment, career advancement and safe and healthy working conditions; 
(b) Protect the rights of persons with disabilities, on an equal basis with others, to just and favourable conditions of work, including equal opportunities and equal remuneration for work of equal value, safe and healthy working conditions, including protection from harassment, and the redress of grievances; 
(c) Ensure that persons with disabilities are able to exercise their labour and trade union rights on an equal basis with others; 
(d) Enable persons with disabilities to have effective access to general technical and vocational guidance programmes, placement services and vocational and continuing training; 
(e) Promote employment opportunities and career advancement for persons with disabilities in the labour market, as well as assistance in finding, obtaining, maintaining and returning to employment; 
(f) Promote opportunities for self-employment, entrepreneurship, the development of cooperatives and starting one's own business; 
(g) Employ persons with disabilities in the public sector; 
(h) Promote the employment of persons with disabilities in the private sector through appropriate policies and measures, which may include affirmative action programmes, incentives and other measures; 
(i) Ensure that reasonable accommodation is provided to persons with disabilities in the workplace; 
(j) Promote the acquisition by persons with disabilities of work experience in the open labour market; 
(k) Promote vocational and professional rehabilitation, job retention and return-to-work programmes for persons with disabilities. 
2. States Parties shall ensure that persons with disabilities are not held in slavery or in servitude, and are protected, on an equal basis with others, from forced or compulsory labour. 

The right is also contained in Article 5 of the African Charter on Human and Peoples' Rights:

Every individual shall have the right to the respect of the dignity inherent in a human being and to the recognition of his legal status. All forms of exploitation and degradation of man particularly slavery, slave trade, torture, cruel, inhuman or degrading punishment and treatment shall be prohibited.