I recently received the question above and answer it herewith.
Firstly, one need to distinguish between a voluntary association and a statutory regulator. In the case of SHEQ, there are a few voluntary associations like Saiosh, SAIOH, SASOHN, SASOM, etc. None of these associations have any statutory powers, which means that were not established by an Act of Parliament.
Then there are those who were established by an Act of Parliament, like the SAHPC and its registration boards, The CBE with ECSA, the SACPCMP, and the other 5 councils as well as SANASP for the Environmental scientists and others.
These statutory bodies all have one thing in common. No person can practice in the fields they regulate, except if a person is registered with them.
Back to the question…
If you join a VA, you bind yourself to their code of conduct and/or ethics. You then get registered if you meet their requirements for registration. Once registered, you remain bound by their codes. Should they receive a complaint that you breached the code, they are required to conduct an investigation and if found that you were in breach of that code, they may impose a sanction on you.
The procedure for reporting and investigation of complaints as well as the possible sanctions can be found in the Constitution of the Association.
Can you still practice after being sanctioned?
In the case of a VA, yes of course. VA rules are part of private law in SA and does not affect the public. It is private agreement between you and your association and its members.
In the case of a Statutory Council, you could be deregistered and may not practice in the field anymore. However, recently in Nthai v Pretoria Society of Advocates and Others (6271/18)  ZALMPPHC 23 (24 May 2019), the court ruled in favour of a reinstatement after being disbarred.
Being deregistered is not something to wish upon a person. Nthai had a 6 year battle to get his “professional status” back.