Rubber infill is one of the main sources of concerns when it comes to the debate about whether or not synthetic grass is a safe product or not. It is feared that when the crumbs become airborne they can be breathed in and tracked into homes on clothes and athletic gear. There are also questions about dermal and ingestional exposures, and about ecosystem effects.

For athletes, the little black rubber pellets may seem little more than a nuisance. Others express more concern, especially when it comes to children’s exposure to the infill. Patti Wood, executive director of the nonprofit Grassroots Environmental Education, argues, “This crumb rubber is a material that cannot be legally disposed of in landfills or ocean-dumped because of its toxicity. Why on earth should we let our children play on it?” Some studies suggest that the same chemicals that can be released profusely during a tire fire may also be released slowly during deterioration of crumb rubber.

The California Office of Environmental Health Hazard Assessment (OEHHA), in the January 2007 report Evaluation of Health Effects of Recycled Waste Tires in Playground and Track Products, concluded that 49 chemicals could be released from tire crumbs. In a hand-wipe experiment, the OEHHA calculated an increased cancer risk of 2.9 in 1 million for ingestion of chrysene (a suspected human carcinogen found in tire rubber) via hand-to-mouth contact with crumb rubber infill. This estimate assumed regular playground use for the first 12 years of life and was termed by the authors to be “slightly higher” than the 1 in 1 million di minimis risk threshold.

The industry has answered the concerns raised by manufacturing new products such as no infill synthetic grass and the recommendation is that you do not need infill if your grassed area is less than 500 square feet and backyard landscaping purposes. The alternative is to move away from using rubber infill and going for sand infill.

Typically, brads are used for thin, delicate moldings as opposed to gun nails which are used for more substantial fastening jobs. Brads are thinner than nails and usually come in 18 gauge sizes.

The more common brad nailers are set up so that the brad cartridge sits horizontal to the brad gun handle to help to drive the brads in straight. However, there are times, particularly when using brads, when the nailing job requires access to tight or angled corners. In order to perform these delicate operations you will need an angled bradder. This will allow you to position the brad gun correctly when nailing beading, stained glass surrounds and cornices.

Brads are used in these situations to avoid splitting thin or delicate wood. A brad will remain the same diameter from one end of the nail to the other, regardless of its length. Brads differ to nails in that nails are generally larger and widen from the tip to the top, giving a more robust fastening.

Nail guns and brad guns both need an electric compressor to provide the air pressure that drives the nails into the wood although the demand is relatively small. Compact models are available with motors rated between ¾ and 2 ½ horsepower in both oil-less and oil-lubricated designs. Either system will be fine for trim installations.

Retinoids are the most effective topical treatment for acne, but they can also irritate the skin more than other acne treatments. They are available in topical skin preparations, such as tretinoin (Retin-A), adapalene (Differin Topical Cream or Gel) and isotretinoin (Isotrex Gel), or as oral medicine (isotretinoin – brand name Roaccutane).

People taking retinoids may need non-oily moisturisers for their lips and face, as well as eye lubricant drops, as they can cause dry skin and eyes. Retinoids can cause severe birth defects, so cannot be taken by pregnant women, those planning pregnancy or women who are not using appropriate contraceptive measures.

Retinoids are natural and synthetic vitamin A derivatives, which regulate development, cell proliferation, and differentiation.

The best known topical retinoid is Tretinoin which is marketed under the names Retin-A, Avita and Renova, although it is also available as a generic brand. Retinoid breaks down in the presence of benzoyl peroxide so it must not be applied at the same time of day.

The way retinoid works is that it increases skin cell turnover which promotes the extrusion of the plugged material in the follicle that is the cause of acne. It also prevents the formation of new acne or comedones.

All of the kinds of retinoids must be prescribed by a health care provider.