Here is a vast and informative list of different oil medium recipes and experiments as to how they perform. The author has also tested the different mediums and drying oils for their yellowing tendency. I'm looking forward to experimenting with some of the mediums that don't use turpentine.

I have been using M. Graham's Walnut Alkyd Medium as a replacement for solvent based oil mediums for a number of years. I have found that even 'odourless' solvents make my throat hurt after only a couple of hours of use. I now stay away from all solvents whilst oil painting, and my studio has only the beautiful smell of drying linseed oil.

From M. Graham's site:

Walnut/Alkyd Medium was developed to provide artist's with a non-toxic, environmentally responsible alternative to solvent based, rapid drying alkyd mediums. This is a medium that closely resembles the wonderful combinations of sun-thickened oil and natural resins used so effectively throughout the history of art but with the singular advantage of being free from solvents.

How I use the medium

• Dipping the brush in a very small amount of medium before picking up a certain colour or mixing a certain colour on the palette. This method gives great control to use as little or as much medium as necessary.
• Mixing the medium into a large amount of paint on the palette - this is best if you have a large area to cover with a specific consistency paint.
• Spreading a small amount of medium onto the canvas forming a 'couch' to paint into. Use a brush or a rag to spread the paint extremely thinly then wipe off all excess with a dry cloth leaving a very slight amount on the canvas to make it slippery. This method is fantastic for glazing and results in very fast drying to a high gloss.
• I have also experimented with mixing the medium with other ingredients to form new mixes. I have mixed it with the Langridge Safe-Gel medium to form a quick drying loose gel. I am also planning to experiment with other ingredients such as stand oil and Venice Turpentine.

Drying Time

• Thin layers or glazes will dry to the touch within 24 hours.
• Thicker layers will dry in a similar time to other solvent based alkyd mediums.

Purchasing

• Australia - The Art Shop.com.au
• Overseas/US - DickBlick.com

Here is a list of non-toxic pigments I found on WetCanvas a while ago:

Violet-Blue
Ultramarine (PB29)

Green-Blue
Phthalocyanine Blue GS (PB15:3)
Manganese Blue (PB33)

Violet-Red
Pyrrole Red (PR254)
Anthraquinoid Red (PR177) (good substitute for Alizarin Crimson in oils)
Naphthol Carbamide (PR170)

Yellow-Red
Quinacridone Red Y (PR209)
Naphthol AS (PR188)

Orange-Yellow
Benzimidazolone Yellow H3G (PY154)
Arylide Yellow RN (PY65)

Green-Yellow
Arylide Yellow 10G (Azo Yellow Light, PY3)
Barium Chromate Lemon (PY31)

Secondary Hue Positions
Ultramarine Violet (PV15)
Dioxazine Purple (PV23RS)
Phthalocyanine Green BS (PB7)
Viridian (PG18)
Chromium Oxide Green (PG17)
Perinone Orange (PO43)
Benzimidazolone Orange H5G (PO62)

Other pigments:
Yellow Ochre, Raw & Burnt Sienna, Raw & Burnt Umber, Red Oxide, Venetian Red, English Red Oxide, Mars Yellow, Mars Orange, Mars Red, Mars Brown, Mars Violet can all be considered completely safe too.

Another site with a list of pigments and their health hazards:
http://www.ci.tucson.az.us/arthazards/paint1.html