Environmentally contaminated speech errors occur when material derived from the speaker's environment but irrelevant to the speaker's intended utterance is erroneously incorporated into speech. Such material may include the names of objects at which speakers are looking, words that speakers are concurrently reading, segments of speech that speakers overhear, or properties of objects in the environment. It was found that although environmental contaminations display less phonological facilitation than other speech error types, they display some semantic facilitation. If the target item and interfering item are from the same syntactic category, a word substitution is more likely to result than a word blend, whereas if the items are from different categories, a blend is more likely. It is hypothesized that environmental contamination occurs at a high level of processing, but with a relatively late insertion point.