Talc(in 16,876 products)
1. Anti-caking Agent - Prevents lumps from forming in food due to excess water. They usually function as a water repellent or by absorbing excess moisture.
2. Bulking Agent - Non-nutritious or inactive substances added to increase stability of the mixture.
3. Gelling Agent / Thickener - Increases the viscosity by thickening the liquid to give it more texture
4. Glazing Agent - A waxy coating which provides protection and prevents water loss
The mineral talc is a hydrous magnesium silicate. A massive talcose rock is called steatite, and an impure massive variety is known as soapstone. Talc is used commercially because of its fragrance retention, luster, purity, softness, and whiteness. Other commercially important properties of talc are its chemical inertness, high dielectric strength, high thermal conductivity, low electrical conductivity, and oil and grease adsorption. Major markets for talc are paper making, plastic, paint and coatings, rubber, food, electric cable, pharmaceuticals, cosmetics, and ceramics. 
Talc is also often used in basketball to keep a player's hands dry. Most tailor's chalk, or French chalk, is talc, as is the chalk often used for welding or metalworking. It is also used as food additive (E number 553B) or in pharmaceutical products as a glidant.
It is approved to use as food additive in EU and generally recognized as safe food substance in US.
In the case of the trial of 22 women against Johnson & Johnson involving J&J's talc products, the plaintiff alleged that J&J's talc products were contaminated with asbestos which caused them to develop ovarian cancer (https://www.bbc.com/news/business-44816805). J&J has denied all accusations of contamination and the FDA has also found no traces of asbestos in J&J's talc samples from 2009 to 2010. The plaintiff then moved to accuse J&J of "flawed testing methods". Since the plaintiff has provided no scientific nor rigorous evidence that talc directly contributed to their occurrence of ovarian cancer, and that the outcome of the case relies on contamination by asbestos, or via flawed testing methods instead of the intrinsic properties of talc itself, the rating on talc shall remain unchanged unless further evidence proves otherwise.
Update: In 2019, the FDA has allegedly found traces of asbestos in J&J's baby powder. "The FDA test indicated the presence of no greater than 0.00002% of chrysotile asbestos in the tested sample, J&J said"
"When talking about whether or not talcum powder is linked to cancer, it is important to distinguish between talc that contains asbestos and talc that is asbestos-free. Talc that has asbestos is generally accepted as being able to cause cancer if it is inhaled. The evidence about asbestos-free talc is less clear." (https://www.cancer.org/cancer/cancer-causes/talcum-powder-and-cancer.html)
In a strange case, a woman inhaled talcum powder for 4 months which led to pulmonary talcosis 10 years later.  As this is a case report instead of a scientific study, details were limited.
The inertness of talc makes it a suitable choice for pleurodesis (where the pleural cavity is sealed up to prevent fluid or air from filling up the lungs). In a case of 78 patients between 1993-1997, it was found that respiratory complications or death resulted in 33% of cases and 9% of patients developed adult respiratory distress syndrome. The case revealed that the rate of complications is significantly higher than those reported in current literature so safer alternatives may need to be explored. 
In a separate study, talc has proven itself to be effective in treating malignant pleural effusion (cancer which causes the pleural cavity to fill up with fluid), and a comparative study between talc poudrage (powder form) and talc slurry (talc mixed with saline solution) showed talc poudrage to be "significantly more effective". 
One of the major health risks of talc is the potential risk of ovarian cancer. “Perineal talc use has been associated with an increased risk of ovarian cancer in a number of case-control studies; however, this association remains controversial because of limited supporting biologic evidence and the potential for recall bias or selection bias in case-control studies.”  In a human study of 215 white females with epithelial ovarian cancer and 215 women from the general population, “Ninety‐two (42.8%) cases regularly used talc either as a dusting powder on the perineum or on sanitary napkins compared with 61 (28.4%) controls. Adjusted for parity and menopausal status, this difference yielded a relative risk of 1.92 (P < 0.003) for ovarian cancer associated with these practices. Women who had regularly engaged in both practices had an adjusted relative risk of 3.28 (P < 0.001) compared to women with neither exposure.”  This provides some support for an association between talc and ovarian cancer. “Talc used regularly in the genital area was associated with a 33% increase in ovarian cancer risk overall while no apparent risk was associated with talc used only in nongenital areas.” 
Overall, it is advised to not intentionally nor excessively breathe in any kind of contaminant without medical supervision. It is unfortunate that there are limited options outside of talc to undergo pleurodesis though talc poudrage seems to be effective in treating malignant pleural effusion. There is also some evidence of an association between talc and ovarian cancer. Talc may be contaminated with asbestos during processing, please see asbestos for further information.
EU CosIng Annex III Restriction Information:
(EC) No 1223/2009
Product Type, body parts:
(a) Powdery products intended to be used for children under 3 years of age
(b) Other products
Wording of conditions of use and warnings:
(a) Keep powder away from children's nose and mouth
2. Pulmonary talcosis 10 years after brief teenage exposure to cosmetic talcum powder (BMJ Case Rep. 2011 Sep 19;2011 DOI: 10.1136/bcr.08.2011.4597)
3. Respiratory failure following talc pleurodesis (Am J Surg. 1999 May;177(5):437-40 DOI: 10.1016/S0002-9610(99)00075-6)
4. Talc poudrage versus talc slurry in the treatment of malignant pleural effusion. A prospective comparative study (Eur J Cardiothorac Surg. 2006 Dec;30(6):827-32 DOI: 10.1016/j.ejcts.2006.10.002)
5. Prospective Study of Talc Use and Ovarian Cancer. (J. Natl. Cancer Inst., 92(3), 249–252. doi:10.1093/jnci/92.3.249)
6. Ovarian cancer and talc. A case-control study. (Cancer, 50(2), 372–376. doi:10.1002/1097-0142(19820715)50:2<372::aid-cncr2820500235>3.0.co;2-s)
7. The Association Between Talc Use and Ovarian Cancer. (Epidemiology, 27(3), 334–346. doi:10.1097/ede.0000000000000434)
1. CANADA INGREDIENT HOTLIST, List of Ingredients that are Restricted for Use in Cosmetic Products 
2. EU CosIng Annex III, SUBSTANCES WITH RESTRICTIONS IN COSMETIC PRODUCTS 
- Ref: III/59
3. Argentina Ministerio de Salud - Restricciones
- Talco: Silicato de magnesio hidratado
4. EU Approved Food Additive 
Safety and Hazards (UN GHS):
1. Causes damage to organs (H370)
2. Causes damage to organs through prolonged or repeated exposure (H372)
Potential Health Concerns For:
1. Hypertension, Pulmonary (PubMed ID:7249763)