Hi Alison,
Thks for input. I agree with most of yr details.
I like preventive since its shorter but i often use preventative probably because it was, I think, more common in the earlier haccp texts. For example the 2003 Codex tree had the "at" but it's been extracted in the 2009 version. Interestingly, in both cases, the text only uses the shorter form. 
Grammatically it seems to be a simply a matter of choice, eg -
http://www.quickandd...us-preventative
@Ace -
In the context of FS- HACCP, specific definitions for CA/PA are often included although sources may vary. CA is typically a Reactive activity, PA is (or, if not, should be) a Proactive (hence the name) one. For example PRPs are Preventive control measures.
Quoting from ASQ -
Quality professionals frequently express confusion as to the difference between corrective and preventive action. A corrective action deals with a nonconformity that has occurred, and a preventive action addresses the potential for a nonconformity to occur. Many ISO 9000 registrar auditors tell their clients to use separate procedures and forms to document each type of action. Nothing in the standard says this must be done, but p. 13 includes the word “prevent” in the clauses on corrective and preventive action.
On closer reading, however, section 8.5.2 says corrective action eliminates the cause of nonconformities to prevent recurrence, and section 8.5.3 says preventive action determines and eliminates the causes of potential noncon- formities … to prevent occurrence. See, there is a difference!
http://asq.org/quali...ive-action.html
Some alternative FS interpretations -
codex
Corrective action - Any action to be taken when the results of monitoring at the CCP indicate a loss of control.
sqf
Correction - Action to eliminate a detected non-conformity. Shall have the same meaning as “corrected.”
Corrective Action - Action to eliminate the cause of a detected non-conformity or other undesirable situation.
Corrective action shall include:
a) Determine / document any immediate action required / taken
i. Determine the cause of the problem
ii. Evaluate action needed on the identified cause
iii. Determine if the problem exists elsewhere in the system and implement actions needed
b) Document the results of the action taken
i. Review/verify and document effectiveness of action taken with objective
evidence.
BRC
Preventive action - Action to eliminate the fundamental, underlying cause (root cause) of a detected non-conformity and prevent recurrence.
Correction - Action to eliminate the cause of a detected non-conformity.
Iso22000
corrective action - action to eliminate the cause of a detected nonconformity or other undesirable situation
Definitions of Prevent(at)ive Actions seem rarer, probably because it is considered to be relatively self-explanatory.
Both terms are fused in CAPA, eg
https://en.wikipedia...eventive_action
If yr query was non specific, I suppose, theoretically, you can make/choose yr own definitions.