Anti-fouling Coatings and Batteries

The Anti-fouling bottom paint you use on the hull of your boat in most cases is very harmful to the marine environment. Antifouling is conducted when biofouling (impairment or degradation due to the growth or activity of living organisms) occurs on a boats hull or mechanical equipment. Biocides are used to inhibit the growth and activity of the microorganisms responsible for biofouling. Because of its toxic effects the practice of antifouling has had a major impact on the marine ecosystem.


Organic booster biocides were recently introduced as alternatives to the organotin of one or more tin atoms in its molecules that are believed to decompose safely, but unfortunately they are now being found as toxins in the food chain. These alternatives were introduced because of the restrictions and bans imposed on the use of Tributyltin (TBT) tributyltin hydride or tributyltin oxide which  are all part of the compound group used in certain biocides. The Rotterdam Convention is considering including them in their treaty.

Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade.

The logo of the Rotterdam Convention Secretariat
The logo of the Rotterdam Convention Secretariat

Type: United Nations Treaty
Signed: September 10th 1998
Location: Rotterdam, The Netherlands
Effective: February 24th 2004
Condition: Ninety days after the ratification by at least 50 signatory states
Signatories: 72 Parties: 153
Depository: Secretary General of the United Nations
Languages: Arabic, Chinese, English, French, Russian, Spanish


Tributyltin compounds have been banned by the International Maritime Organization which was established in Geneva 1948 and met for the first time.

UN flag
United Nations

Org Type: UN Agency
Acronyms: IMO
Head: Koji Sekimizu
Status: Active
Established: 1959


The IMO develops and maintains a comprehensive regulatory framework for shipping. These include safety, environment, legal, technical, security, and efficiency in maritime shipping.

Replacement products are usually based on copper metal oxides and organic biocides. The biocides used in antifouling paints include: chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211®), Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine), zinc pyrithione and Zineb. The risks with the use of these products in aquaculture (aquafarming) include both humans and predators ingesting fish and shellfish that have ingested these contaminants which result in the antibiotic resistant bacteria.

Newer versions of these products are said to be less toxic and have a shorter toxic life span. The three main types used today are the ablative, non-ablative, and hard anti-fouling. The hard anti-fouling coatings are considered to be the least harmful to the environment. This particular coatings extended anti-fouling properties leach and slough fewer toxic metals into the water.

Tips on safe use of Anti-fouling Coatings:

  • Collect all anti-fouling coating that you remove from your boats hull and dispose of it properly at your local household waste disposal centre.
  • The “non-fouling” paints that contain Silicon, Teflon, Resin, and other like materials work because their slick surfaces inhibit marine growth.
  • Another method for anti-fouling is to use regular hull paint covered with a coat of slick bottom wax.
  • Storing small boats on land helps you to avoid using anti-fouling paint.
  • Always treat and dispose of solvents, thinners, old paint, etc as hazardous waste in the appropriate household waste facilities or offer them to other boaters who might need them.
  • Clean your boats hull often to help reduce the need for anti-fouling coatings.


  • Recycle all old batteries
  • Cleaning battery terminals with baking soda, rinsing them with fresh water, and coating the terminals ends with petroleum jelly will help reduce corrosion.
  • Keeping the battery cells filled with distilled water and fully charged will help to prevent them from freezing in colder weather.