Belsky served for "more than 28 years" as a senior kashrut advisor to the OU.
He faced criticism for his statements in reaction to sexual abuse accusations made against a Jewish camp counselor.
Belsky received his semicha from Yeshiva Torah Vodaas, in Brooklyn, NY, in 1962, and from Rabbi Moshe Feinstein in 1965. He also studied at Beth Medrash Elyon for a number of years. His Rosh Yeshiva was Rav Yaakov Kamenetsky.
He served as a member of a Beth din under, successively, Rabbis Yitzchok Isaac Liebes, Baruch Leizerowski, and Herschel Kurzrock. Some events that he addressed with this beth din were: the aftermath of the 9/11 World Trade Center attack and freeing its widows from agunah status, New York City tap water, human-hair wigs from India, surrogate motherhood, and a kashrus scandal in Monsey.
His first kashrus position was with the Kof-K. He served with the Orthodox Union starting in 1987, and was eventually described as one of "the chief experts for the Orthodox Union, which certifies more than 600,000 products as kosher." In 2004, Belsky ruled that water that might contain microscopic nonkosher organisms is kosher even if it is unfiltered. The same year he ruled that "gruesome" slaughtering of animals at Agriprocessors, then the largest glatt kosher meat producer in the United States, appeared not to violate kosher laws as long as the animal "felt nothing". He later ruled on a kashrus scandal surrounding Doheny Meats, which had been videoed violating the laws of kashrus, saying that food that had been sold by Doheny prior to the scandal could still be considered kosher.
In September 2005, Belsky served as the keynote speaker at the Igud Horabbonim Annual Siyum HaShas. The event also served as the chag ha’semichah where 35 students of his received their certificates of semichah.
Belsky publicly defended confessed sexual abuser Yosef Kolko, who taught children at a Lakewood, New Jersey, yeshiva. Further, he condemned the victim and his parents for reporting the sexual abuse to the police, and wrote that one who does so "has no share in the world to come." Belsky was criticized for his actions in this regard. According to The Jewish Week, the Ocean County, New Jersey District Attorney privately warned Belsky to cease and desist writing letters defending Kolko, or risk prosecution.
According to court documents, Belsky was alleged to have served on a Beth din together with Mendel Epstein and Martin Wolmark which approved the use of physical violence against Jews who were civilly divorced, yet refused to give a get (Jewish divorce document) to their wives.
In 2000, Belsky opposed the creation of an eruv in Brooklyn, and said the issue was not for "amateurs."
In a 2011 interview with The New York Times about a divorce case, Belsky described a court-ordered child custody order as "a joke" since it allegedly interfered with observance of the Jewish Sabbath.
Belsky was the son of Rabbi Berel and Chana Tzirel Belsky. His maternal grandfather is Binyomin Wilhelm, a founder of Yeshiva Torah Vodaas.
In 2012, he suffered a serious medical emergency. At that time, the name Chaim was added to Rav Belsky's name. He recovered, and was able to return to Torah Vodaath. In 2013, the annual Yeshiva Torah Vodaath dinner honored the rosh yeshiva and highlighted 50 young men who earned semichah from him.
Belsky was re-hospitalized in January 2016 and died on January 28, 2016.Piske halakhot (Brooklyn 2002) - responsa
Einei Yisroel on Chumash (currently Bereishis, Shemos, Vayikra, and Devarim) (Kiryat Sefer 2005, 2006, 2011, and 2008 respectively) - Lectures edited and adapted by Moshe Armel and Reuven Mathieson
Sha'alos U'Teshuvos Shulchan Halevi, questions and answers on a wide variety of topics, (Kiryat Sefer 2008)