>The polystyrene gives off styrene monomer for a while.

Interesting.  Below is all I could find that suggests this:

I wonder if any of the gases resemble chemical signals bees use?

--- excerpts from http://www.dyplastproducts.com/EPS_MSDS_0711.htm ---

NGREDIENT A: Polystyrene Foam (Ethenylbenzene homopolymer)
INGREDIENT B: Pentane Isomers (n-pentane, isopentane, cyclopentane)
INGREDIENT C: Styrene (residual vinyl benzene)

Note 1:NFPA and HMIS ratings based on pentane hazards, which are dramatically diminished by the time the product reaches the end-user - - at which time the above ratings would be less.

ROUTES OF ENTRY: During manufacture or re-grinding, inhalation or eye exposure to dust from this product dust may cause temporary irritation. Skin exposure to the product may cause mechanical irritation. Typical consumer contact would be through breathing of off-gases (i.e. pentane isomers).

POTENTIAL HEALTH EFFECTS

Summary: Inhalation or eye exposure to dust from this product may cu

Acute Inhalation: Breathing dust may cause temporary mechanical irritation and coughing.

Overexposure to extremely high concentrations of pentane can cause narcotic effects. Signs and symptoms of overexposure to pentane include headache, nausea, dizziness, difficulty walking or sleepiness.

Chronic Inhalation: None identified.

Acute Skin Contact: Direct contact with rough cut foam can cause mechanical abrasion to
exposed skin. Absorption through skin is unlikely.

Acute Eye Contact: Eye contact may cause mild mechanical irritation, redness, tearing and
blurred vision.

Chronic Eye Contact: None identified.

Acute Ingestion: Ingestion of this material is unlikely if used as intended. However,
ingestion of this product mayproduce gastrointestinal irritation and disturbances.

Chronic Ingestion: None identified.

Carcinogenicity: Styrene monomer

ACGIH: A4 – Not Classifiable as a Human Carcinogen

IARC: 2B – Possibly Carcinogenic to Humans (Vol. 60, 1994)

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm