"Where there was always a rule around immoderate consumption, we've added some more language in there around irresponsibility," she added.
The code was regularly reviewed and the merger did not come as the result of advertisers getting through loopholes, she said.
"With the alcohol code we have a pretty strict policy of regular review because it's an area of high interest and we have a particular process we follow for the review of that code."
The environmental code has a more detailed introduction and part of it has been rewritten.
It now states that:
*Environmental claims shall be relevant, specific and clearly explain the significance of the claim in language readily understood by consumers.
* Environmental claims shall be made only where there is a genuine benefit, not where they are simply promoting the observance of existing law.
* Environmental claims shall not overstate the level of scientific acceptance.
The changes did not come as the result of ads the ASA could not penalise, the spokeswoman said.
"We had a code that was quite old, and we've had a situation where there's been a lot more interest in this type of claim."
The code now better reflected what was happening in the advertising environment, she said.